Updating release to sign checksums

* Initial plan

* chore: pin GitHub Actions dependencies to specific commit SHAs (OSSF)

Agent-Logs-Url: https://github.com/mikefarah/yq/sessions/cbd03f0a-f2dc-4da4-b01c-7dd06ad83ee9

Co-authored-by: mikefarah <1151925+mikefarah@users.noreply.github.com>

* chore: pin Dockerfile base images to specific SHA digests (OSSF)

Agent-Logs-Url: https://github.com/mikefarah/yq/sessions/7a8f6690-37fb-42ab-b3dc-0dd23c270fbe

Co-authored-by: mikefarah <1151925+mikefarah@users.noreply.github.com>

* chore: revert yq pins in test-yq.yml; add release note for github-action/Dockerfile SHA

Agent-Logs-Url: https://github.com/mikefarah/yq/sessions/e1b35d79-92a3-47d5-b4ac-a2efe2fd58ce

Co-authored-by: mikefarah <1151925+mikefarah@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: mikefarah <1151925+mikefarah@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report_v4.md

@@ -34,13 +34,13 @@ The command you ran:
 yq eval-all 'select(fileIndex==0) | .a.b.c' data1.yml data2.yml
 ```
 
-**Actual behavior**
+**Actual behaviour**
 
 ```yaml
 cat: meow
 ```
 
-**Expected behavior**
+**Expected behaviour**
 
 ```yaml
 this: should really work

.github/instructions/instructions.md

@@ -0,0 +1 @@
+When you find a bug - make sure to include a new test that exposes the bug, as well as the fix for the bug itself.

.github/workflows/codeql.yml

@@ -38,11 +38,11 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v6
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@c10b8064de6f491fea524254123dbe5e09572f13 # v4.35.1
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -53,7 +53,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v4
+      uses: github/codeql-action/autobuild@c10b8064de6f491fea524254123dbe5e09572f13 # v4.35.1
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
@@ -67,4 +67,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@c10b8064de6f491fea524254123dbe5e09572f13 # v4.35.1

.github/workflows/docker-release.yml

@@ -14,16 +14,16 @@ jobs:
       IMAGE_NAME: mikefarah/yq
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4.0.0
         with:
           platforms: all
 
       - name: Set up Docker Buildx
         id: buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
         with:
           version: latest
 
@@ -31,13 +31,13 @@ jobs:
         run: echo ${{ steps.buildx.outputs.platforms }} && docker version
 
       - name: Login to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           registry: ghcr.io
           username: ${{ github.actor }}

.github/workflows/go.yml

@@ -11,13 +11,13 @@ jobs:
     steps:
 
     - name: Set up Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
       with:
         go-version: '^1.20'
       id: go
 
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v6
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
     - name: Get dependencies
       run: |

.github/workflows/release.yml

@@ -8,9 +8,12 @@ on:
 jobs:
   publishGitRelease:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      id-token: write
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-go@v5
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
           go-version: '^1.20'
           check-latest: true
@@ -37,14 +40,22 @@ jobs:
             --output=yq.1
             man.md
 
+      - name: Install cosign
+        uses: sigstore/cosign-installer@v3
+
       - name: Cross compile
         run: |
           sudo apt-get install rhash -y
           go install github.com/goreleaser/goreleaser/v2@latest
           ./scripts/xcompile.sh
 
+      - name: Sign checksums
+        run: |
+          cosign sign-blob --yes --output-bundle build/checksums.bundle build/checksums
+          cosign sign-blob --yes --output-bundle build/checksums-bsd.bundle build/checksums-bsd
+
       - name: Release
-        uses: softprops/action-gh-release@v1
+        uses: softprops/action-gh-release@3bb12739c298aeb8a4eeaf626c5b8d85266b0e65 # v2.6.2
         with:
           files: build/*
           draft: true

.github/workflows/snap-release.yml

@@ -12,14 +12,14 @@ jobs:
       environment: snap
       runs-on: ubuntu-latest
       steps:
-        - uses: actions/checkout@v6
-        - uses: snapcore/action-build@v1
+        - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        - uses: snapcore/action-build@3bdaa03e1ba6bf59a65f84a751d943d549a54e79 # v1.3.0
           id: build
           env:
             SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
           with:
             snapcraft-args: "remote-build --launchpad-accept-public-upload"
-        - uses: snapcore/action-publish@v1
+        - uses: snapcore/action-publish@214b86e5ca036ead1668c79afb81e550e6c54d40 # v1.2.0
           env:
             SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
           with:

.github/workflows/test-yq.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Get test
         id: get_value
         uses: mikefarah/yq@master

.gitignore

@@ -43,9 +43,11 @@ yq*.snap
 
 test.yml
 test*.yml
+test*.tf
 test*.xml
 test*.toml
 test*.yaml
+*.kyaml
 test_dir1/
 test_dir2/
 0.yml
@@ -68,3 +70,7 @@ debian/files
 .vscode
 
 yq3
+
+# Golang
+.gomodcache/
+.gocache/

.golangci.yml

@@ -14,6 +14,11 @@ linters:
     - unconvert
     - unparam
   settings:
+    misspell:
+      locale: UK
+      ignore-rules:
+        - color
+        - colors
     depguard:
       rules:
         prevent_unmaintained_packages:

.goreleaser.yaml

@@ -39,7 +39,6 @@ builds:
       - openbsd_amd64
       - windows_386
       - windows_amd64
-      - windows_arm
       - windows_arm64
 
     no_unique_dist_dir: true

CODE_OF_CONDUCT.md

@@ -11,7 +11,7 @@ appearance, race, religion, or sexual identity and orientation.
 
 ## Our Standards
 
-Examples of behavior that contributes to creating a positive environment
+Examples of behaviour that contributes to creating a positive environment
 include:
 
 * Using welcoming and inclusive language
@@ -20,7 +20,7 @@ include:
 * Focusing on what is best for the community
 * Showing empathy towards other community members
 
-Examples of unacceptable behavior by participants include:
+Examples of unacceptable behaviour by participants include:
 
 * The use of sexualized language or imagery and unwelcome sexual attention or
  advances
@@ -34,13 +34,13 @@ Examples of unacceptable behavior by participants include:
 ## Our Responsibilities
 
 Project maintainers are responsible for clarifying the standards of acceptable
-behavior and are expected to take appropriate and fair corrective action in
-response to any instances of unacceptable behavior.
+behaviour and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behaviour.
 
 Project maintainers have the right and responsibility to remove, edit, or
 reject comments, commits, code, wiki edits, issues, and other contributions
 that are not aligned to this Code of Conduct, or to ban temporarily or
-permanently any contributor for other behaviors that they deem inappropriate,
+permanently any contributor for other behaviours that they deem inappropriate,
 threatening, offensive, or harmful.
 
 ## Scope
@@ -54,7 +54,7 @@ further defined and clarified by project maintainers.
 
 ## Enforcement
 
-Instances of abusive, harassing, or otherwise unacceptable behavior may be
+Instances of abusive, harassing, or otherwise unacceptable behaviour may be
 reported by contacting the project team at mikefarah@gmail.com. All
 complaints will be reviewed and investigated and will result in a response that
 is deemed necessary and appropriate to the circumstances. The project team is

CONTRIBUTING.md

@@ -197,6 +197,21 @@ Note: PRs with small changes (e.g. minor typos) may not be merged (see https://j
   make [local] test    # Run in Docker container
   ```
 
+- **Problem**: Tests fail with a VCS error:
+  ```bash
+  error obtaining VCS status: exit status 128
+  Use -buildvcs=false to disable VCS stamping.
+  ```
+- **Solution**:
+  Git security mechanisms prevent Golang from detecting the Git details inside
+  the container; either build with the `local` option, or pass GOFLAGS to
+  disable Golang buildvcs behaviour.
+  ```bash
+  make local test
+  # OR
+  make test GOFLAGS='-buildvcs=true'
+  ```
+
 ### Documentation Generation Issues
 - **Problem**: Generated docs don't update after test changes
 - **Solution**: 

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.25.5 AS builder
+FROM golang:1.26.2@sha256:2a2b4b5791cea8ae09caecba7bad0bd9631def96e5fe362e4a5e67009fe4ae61 AS builder
 
 WORKDIR /go/src/mikefarah/yq
 
@@ -10,7 +10,7 @@ RUN ./scripts/acceptance.sh
 
 # Choose alpine as a base image to make this useful for CI, as many
 # CI tools expect an interactive shell inside the container
-FROM alpine:3 AS production
+FROM alpine:3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 AS production
 LABEL maintainer="Mike Farah <mikefarah@users.noreply.github.com>"
 
 COPY --from=builder /go/src/mikefarah/yq/yq /usr/bin/yq

Dockerfile.dev

@@ -1,4 +1,4 @@
-FROM golang:1.25.5
+FROM golang:1.26.2@sha256:2a2b4b5791cea8ae09caecba7bad0bd9631def96e5fe362e4a5e67009fe4ae61
 
 RUN apt-get update && \
     apt-get install -y npm && \

Makefile

@@ -35,6 +35,7 @@ clean:
 ## prefix before other make targets to run in your local dev environment
 local: | quiet
 	@$(eval ENGINERUN= )
+	@$(eval GOFLAGS="$(GOFLAGS)" )
 	@mkdir -p tmp
 	@touch tmp/dev_image_id
 quiet: # this is silly but shuts up 'Nothing to be done for `local`'

Makefile.variables

@@ -4,6 +4,7 @@ IMPORT_PATH := github.com/mikefarah/${PROJECT}
 export GIT_COMMIT = $(shell git rev-parse --short HEAD)
 export GIT_DIRTY = $(shell test -n "$$(git status --porcelain)" && echo "+CHANGES" || true)
 export GIT_DESCRIBE = $(shell git describe --tags --always)
+GOFLAGS :=
 LDFLAGS :=
 LDFLAGS += -X main.GitCommit=${GIT_COMMIT}${GIT_DIRTY}
 LDFLAGS += -X main.GitDescribe=${GIT_DESCRIBE}
@@ -26,13 +27,15 @@ ifeq ($(CYG_CHECK),1)
 else
 	# all non-windows environments
 	ROOT := $(shell pwd)
-	SELINUX := $(shell which getenforce 2>&1 >/dev/null && echo :z)
+	# Deliberately use `command -v` instead of `which` to be POSIX compliant
+	SELINUX := $(shell command -v getenforce >/dev/null 2>&1 && echo :z)
 endif
 
 DEV_IMAGE := ${PROJECT}_dev
 
 ENGINERUN := ${ENGINE} run --rm \
 	-e LDFLAGS="${LDFLAGS}" \
+	-e GOFLAGS="${GOFLAGS}" \
 	-e GITHUB_TOKEN="${GITHUB_TOKEN}" \
 	-v ${ROOT}/vendor:/go/src${SELINUX} \
 	-v ${ROOT}:/${PROJECT}/src/${IMPORT_PATH}${SELINUX} \

README.md

@@ -3,7 +3,7 @@
 ![Build](https://github.com/mikefarah/yq/workflows/Build/badge.svg)  ![Docker Pulls](https://img.shields.io/docker/pulls/mikefarah/yq.svg) ![Github Releases (by Release)](https://img.shields.io/github/downloads/mikefarah/yq/total.svg) ![Go Report](https://goreportcard.com/badge/github.com/mikefarah/yq) ![CodeQL](https://github.com/mikefarah/yq/workflows/CodeQL/badge.svg)
 
 
-A lightweight and portable command-line YAML, JSON, INI and XML processor. `yq` uses [jq](https://github.com/stedolan/jq) (a popular JSON processor) like syntax but works with yaml files as well as json, xml, ini, properties, csv and tsv. It doesn't yet support everything `jq` does - but it does support the most common operations and functions, and more is being added continuously.
+A lightweight and portable command-line YAML, JSON, INI and XML processor. `yq` uses [jq](https://github.com/stedolan/jq) (a popular JSON processor) like syntax but works with yaml files as well as json, kyaml, xml, ini, properties, csv and tsv. It doesn't yet support everything `jq` does - but it does support the most common operations and functions, and more is being added continuously.
 
 yq is written in Go - so you can download a dependency free binary for your platform and you are good to go! If you prefer there are a variety of package managers that can be used as well as Docker and Podman, all listed below.
 
@@ -363,6 +363,8 @@ gah install yq
 - [Load content from other files](https://mikefarah.gitbook.io/yq/operators/load)
 - [Convert to/from json/ndjson](https://mikefarah.gitbook.io/yq/v/v4.x/usage/convert)
 - [Convert to/from xml](https://mikefarah.gitbook.io/yq/v/v4.x/usage/xml)
+- [Convert to/from hcl (terraform)](https://mikefarah.gitbook.io/yq/v/v4.x/usage/hcl)
+- [Convert to/from toml](https://mikefarah.gitbook.io/yq/v/v4.x/usage/toml)
 - [Convert to/from properties](https://mikefarah.gitbook.io/yq/v/v4.x/usage/properties)
 - [Convert to/from csv/tsv](https://mikefarah.gitbook.io/yq/usage/csv-tsv)
 - [General shell completion scripts (bash/zsh/fish/powershell)](https://mikefarah.gitbook.io/yq/v/v4.x/commands/shell-completion)
@@ -413,7 +415,7 @@ Flags:
   -h, --help                            help for yq
   -I, --indent int                      sets indent level for output (default 2)
   -i, --inplace                         update the file in place of first file given.
-  -p, --input-format string             [auto|a|yaml|y|json|j|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|lua|l|ini|i] parse format for input. (default "auto")
+  -p, --input-format string             [auto|a|yaml|y|json|j|kyaml|ky|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|hcl|h|lua|l|ini|i] parse format for input. (default "auto")
       --lua-globals                     output keys as top-level global variables
       --lua-prefix string               prefix (default "return ")
       --lua-suffix string               suffix (default ";\n")
@@ -422,7 +424,7 @@ Flags:
   -N, --no-doc                          Don't print document separators (---)
   -0, --nul-output                      Use NUL char to separate values. If unwrap scalar is also set, fail if unwrapped scalar contains NUL char.
   -n, --null-input                      Don't read input, simply evaluate the expression given. Useful for creating docs from scratch.
-  -o, --output-format string            [auto|a|yaml|y|json|j|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|shell|s|lua|l|ini|i] output format type. (default "auto")
+  -o, --output-format string            [auto|a|yaml|y|json|j|kyaml|ky|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|hcl|h|shell|s|lua|l|ini|i] output format type. (default "auto")
   -P, --prettyPrint                     pretty print, shorthand for '... style = ""'
       --properties-array-brackets       use [x] in array paths (e.g. for SpringBoot)
       --properties-separator string     separator to use between keys and values (default " = ")

SECURITY.md

@@ -0,0 +1,26 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+Please **do not** report security vulnerabilities through public GitHub issues.
+
+Instead, use GitHub's private vulnerability reporting feature:
+👉 https://github.com/mikefarah/yq/security
+
+This allows vulnerabilities to be triaged and addressed confidentially before any public disclosure.
+
+## Scope
+
+### HTTP / TLS / Network vulnerabilities
+
+yq is a command-line YAML/JSON/TOML processor that reads from files or standard input and writes to standard output. **yq does not include any HTTP or network libraries** and makes no network connections at runtime. CVEs related to HTTP, TLS, or networking are therefore **not applicable** to yq.
+
+### Dependency version bumps
+
+yq uses [Dependabot](https://docs.github.com/en/code-security/dependabot) to automatically raise pull requests for:
+
+- Go module dependencies
+- Go toolchain version
+- Docker base images
+
+Please **do not** raise pull requests or issues solely to bump dependency or Go versions — Dependabot handles this automatically and the maintainers merge those PRs regularly.

acceptance_tests/inputs-format.sh

@@ -6,6 +6,7 @@ setUp() {
   rm test*.csv 2>/dev/null || true
   rm test*.tsv 2>/dev/null || true
   rm test*.xml 2>/dev/null || true
+  rm test*.tf 2>/dev/null || true
 }
 
 testInputProperties() {
@@ -153,6 +154,37 @@ EOM
   assertEquals "$expected" "$X"
 }
 
+testInputKYaml() {
+  cat >test.kyaml <<'EOL'
+# leading
+{
+  a: 1, # a line
+  # head b
+  b: 2,
+  c: [
+    # head d
+    "d", # d line
+  ],
+}
+EOL
+
+  read -r -d '' expected <<'EOM'
+# leading
+a: 1 # a line
+# head b
+b: 2
+c:
+  # head d
+  - d # d line
+EOM
+
+  X=$(./yq e -p=kyaml -P test.kyaml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -p=kyaml -P test.kyaml)
+  assertEquals "$expected" "$X"
+}
+
 
 
 
@@ -255,4 +287,61 @@ EOM
   assertEquals "$expected" "$X"
 }
 
-source ./scripts/shunit2
+testInputTerraform() {
+  cat >test.tf <<EOL
+resource "aws_s3_bucket" "example" {
+  bucket = "my-bucket"
+  tags = {
+    Environment = "Dev"
+    Project = "Test"
+  }
+}
+EOL
+
+  read -r -d '' expected << EOM
+resource "aws_s3_bucket" "example" {
+  bucket = "my-bucket"
+  tags = {
+    Environment = "Dev"
+    Project = "Test"
+  }
+}
+EOM
+
+  X=$(./yq test.tf)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea test.tf)
+  assertEquals "$expected" "$X"
+}
+
+testInputTerraformGithubAction() {
+  cat >test.tf <<EOL
+resource "aws_s3_bucket" "example" {
+  bucket = "my-bucket"
+  
+  tags = {
+    Environment = "Dev"
+    Project = "Test"
+  }
+}
+EOL
+
+  read -r -d '' expected << EOM
+resource "aws_s3_bucket" "example" {
+  bucket = "my-bucket"
+  tags = {
+    Environment = "Dev"
+    Project = "Test"
+  }
+}
+EOM
+
+  X=$(cat /dev/null | ./yq test.tf)
+  assertEquals "$expected" "$X"
+
+  X=$(cat /dev/null | ./yq ea test.tf)
+  assertEquals "$expected" "$X"
+}
+
+source ./scripts/shunit2

acceptance_tests/output-format.sh

@@ -280,6 +280,55 @@ EOM
   assertEquals "$expected" "$X"
 }
 
+testOutputKYaml() {
+  cat >test.yml <<'EOL'
+# leading
+a: 1 # a line
+# head b
+b: 2
+c:
+  # head d
+  - d # d line
+EOL
+
+  read -r -d '' expected <<'EOM'
+# leading
+{
+  a: 1, # a line
+  # head b
+  b: 2,
+  c: [
+    # head d
+    "d", # d line
+  ],
+}
+EOM
+
+  X=$(./yq e --output-format=kyaml test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea --output-format=kyaml test.yml)
+  assertEquals "$expected" "$X"
+}
+
+testOutputKYamlShort() {
+  cat >test.yml <<EOL
+a: b
+EOL
+
+  read -r -d '' expected <<'EOM'
+{
+  a: "b",
+}
+EOM
+
+  X=$(./yq e -o=ky test.yml)
+  assertEquals "$expected" "$X"
+
+  X=$(./yq ea -o=ky test.yml)
+  assertEquals "$expected" "$X"
+}
+
 testOutputXmComplex() {
   cat >test.yml <<EOL
 a: {b: {c: ["cat", "dog"], +@f: meow}}

agents.md

@@ -0,0 +1,422 @@
+# General rules
+✅ **DO:**
+- You can use ./yq with the `--debug-node-info` flag to get a deeper understanding of the ast.
+- run ./scripts/format.sh to format the code; then ./scripts/check.sh lint and finally ./scripts/spelling.sh to check spelling.
+- Add comprehensive tests to cover the changes
+- Run test suite to ensure there is no regression
+- Use UK english spelling
+
+❌ **DON'T:**
+- Git add or commit
+- Add comments to functions that are self-explanatory
+
+
+
+# Adding a New Encoder/Decoder
+
+This guide explains how to add support for a new format (encoder/decoder) to yq without modifying `candidate_node.go`.
+
+## Overview
+
+The encoder/decoder architecture in yq is based on two main interfaces:
+
+- **Encoder**: Converts a `CandidateNode` to output in a specific format
+- **Decoder**: Reads input in a specific format and creates a `CandidateNode`
+
+Each format is registered in `pkg/yqlib/format.go` and made available through factory functions.
+
+## Architecture
+
+### Key Files
+
+- `pkg/yqlib/encoder.go` - Defines the `Encoder` interface
+- `pkg/yqlib/decoder.go` - Defines the `Decoder` interface
+- `pkg/yqlib/format.go` - Format registry and factory functions
+- `pkg/yqlib/operator_encoder_decoder.go` - Encode/decode operators
+- `pkg/yqlib/encoder_*.go` - Encoder implementations
+- `pkg/yqlib/decoder_*.go` - Decoder implementations
+
+### Interfaces
+
+**Encoder Interface:**
+```go
+type Encoder interface {
+    Encode(writer io.Writer, node *CandidateNode) error
+    PrintDocumentSeparator(writer io.Writer) error
+    PrintLeadingContent(writer io.Writer, content string) error
+    CanHandleAliases() bool
+}
+```
+
+**Decoder Interface:**
+```go
+type Decoder interface {
+    Init(reader io.Reader) error
+    Decode() (*CandidateNode, error)
+}
+```
+
+## Step-by-Step: Adding a New Encoder/Decoder
+
+### Step 1: Create the Encoder File
+
+Create `pkg/yqlib/encoder_<format>.go` implementing the `Encoder` interface:
+- `Encode()` - Convert a `CandidateNode` to your format and write to the output writer
+- `PrintDocumentSeparator()` - Handle document separators if your format requires them
+- `PrintLeadingContent()` - Handle leading content/comments if supported
+- `CanHandleAliases()` - Return whether your format supports YAML aliases
+
+See `encoder_json.go` or `encoder_base64.go` for examples.
+
+### Step 2: Create the Decoder File
+
+Create `pkg/yqlib/decoder_<format>.go` implementing the `Decoder` interface:
+- `Init()` - Initialize the decoder with the input reader and set up any needed state
+- `Decode()` - Decode one document from the input and return a `CandidateNode`, or `io.EOF` when finished
+
+See `decoder_json.go` or `decoder_base64.go` for examples.
+
+### Step 3: Create Tests (Mandatory)
+
+Create a test file `pkg/yqlib/<format>_test.go` using the `formatScenario` pattern:
+- Define test scenarios as `formatScenario` structs with fields: `description`, `input`, `expected`, `scenarioType`
+- `scenarioType` can be `"decode"` (test decoding to YAML) or `"roundtrip"` (encode/decode preservation)
+- Create a helper function `test<Format>Scenario()` that switches on `scenarioType`
+- Create main test function `Test<Format>FormatScenarios()` that iterates over scenarios
+- The main test function should use `documentScenarios` to ensure testcase documentation is generated.
+
+Test coverage must include:
+- Basic data types (scalars, arrays, objects/maps)
+- Nested structures
+- Edge cases (empty inputs, special characters, escape sequences)
+- Format-specific features or syntax
+- Round-trip tests: decode → encode → decode should preserve data
+
+See `hcl_test.go` for a complete example.
+
+### Step 4: Register the Format in format.go
+
+Edit `pkg/yqlib/format.go`:
+
+1. Add a new format variable:
+   - `"<format>"` is the formal name (e.g., "json", "yaml")
+   - `[]string{...}` contains short aliases (can be empty)
+   - The first function creates an encoder (can be nil for encode-only formats)
+   - The second function creates a decoder (can be nil for decode-only formats)
+
+2. Add the format to the `Formats` slice in the same file
+
+See existing formats in `format.go` for the exact structure.
+
+### Step 5: Handle Encoder Configuration (if needed)
+
+If your format has preferences/configuration options:
+
+1. Create a preferences struct with your configuration fields
+2. Update the encoder to accept preferences in its factory function
+3. Update `format.go` to pass the configured preferences
+4. Update `operator_encoder_decoder.go` if special indent handling is needed (see existing formats like JSON and YAML for the pattern)
+
+This pattern is optional and only needed if your format has user-configurable options.
+
+## Build Tags
+
+Use build tags to allow optional compilation of formats:
+- Add `//go:build !yq_no<format>` at the top of your encoder and decoder files
+- Create a no-build version in `pkg/yqlib/no_<format>.go` that returns nil for encoder/decoder factories
+
+This allows users to compile yq without certain formats using: `go build -tags yq_no<format>`
+
+## Working with CandidateNode
+
+The `CandidateNode` struct represents a YAML node with:
+- `Kind`: The node type (ScalarNode, SequenceNode, MappingNode)
+- `Tag`: The YAML tag (e.g., "!!str", "!!int", "!!map")
+- `Value`: The scalar value (for ScalarNode only)
+- `Content`: Child nodes (for SequenceNode and MappingNode)
+
+Key methods:
+- `node.guessTagFromCustomType()` - Infer the tag from Go type
+- `node.AsList()` - Convert to a list for processing
+- `node.CreateReplacement()` - Create a new replacement node
+- `NewCandidate()` - Create a new CandidateNode
+
+## Key Points
+
+✅ **DO:**
+- Implement only the `Encoder` and `Decoder` interfaces
+- Register your format in `format.go` only
+- Keep format-specific logic in your encoder/decoder files
+- Use the candidate_node style attribute to store style information for round-trip. Ask if this needs to be updated with new styles.
+- Use build tags for optional compilation
+- Add comprehensive tests
+- Run the specific encoder/decoder test (e.g. <format>_test.go) whenever you make ay changes to the encoder_<format> or decoder_<format>
+- Handle errors gracefully
+- Add the no build directive, like the xml encoder and decoder, that enables a minimal yq builds. e.g.  `//go:build !yq_<format>`. Be sure to also update the build_small-yq.sh and build-tinygo-yq.sh to not include the new format.
+
+❌ **DON'T:**
+- Modify `candidate_node.go` to add format-specific logic
+- Add format-specific fields to `CandidateNode`
+- Create special cases in core navigation or evaluation logic
+- Bypass the encoder/decoder interfaces
+- Use candidate_node tag attribute for anything other than indicate the data type
+
+## Examples
+
+Refer to existing format implementations for patterns:
+
+- **Simple encoder/decoder**: `encoder_json.go`, `decoder_json.go`
+- **Complex with preferences**: `encoder_yaml.go`, `decoder_yaml.go`
+- **Encoder-only**: `encoder_sh.go` (ShFormat has nil decoder)
+- **String-only operations**: `encoder_base64.go`, `decoder_base64.go`
+
+## Testing Your Implementation (Mandatory)
+
+Tests must be implemented in `<format>_test.go` following the `formatScenario` pattern:
+
+1. **Create test scenarios** using the `formatScenario` struct with fields:
+   - `description`: Brief description of what's being tested
+   - `input`: Sample input in your format
+   - `expected`: Expected output (typically in YAML for decode tests)
+   - `scenarioType`: Either `"decode"` or `"roundtrip"`
+
+2. **Test coverage must include:**
+   - Basic data types (scalars, arrays, objects/maps)
+   - Nested structures
+   - Edge cases (empty inputs, special characters, escape sequences)
+   - Format-specific features or syntax
+   - Round-trip tests: decode → encode → decode should preserve data
+
+3. **Test function pattern:**
+   - `test<Format>Scenario()`: Helper function that switches on `scenarioType`
+   - `Test<Format>FormatScenarios()`: Main test function that iterates over scenarios
+
+4. **Example from existing formats:**
+   - See `hcl_test.go` for a complete example
+   - See `yaml_test.go` for YAML-specific patterns
+   - See `json_test.go` for more complex scenarios
+
+## Common Patterns
+
+### Format with Indentation
+Use preferences to control output formatting:
+```go
+type <format>Preferences struct {
+    Indent int
+}
+
+func (prefs *<format>Preferences) Copy() <format>Preferences {
+    return *prefs
+}
+```
+
+### Multiple Documents
+Decoders should support reading multiple documents:
+```go
+func (dec *<format>Decoder) Decode() (*CandidateNode, error) {
+    if dec.finished {
+        return nil, io.EOF
+    }
+    // ... decode next document ...
+    if noMoreDocuments {
+        dec.finished = true
+    }
+    return candidate, nil
+}
+```
+
+---
+
+# Adding a New Operator
+
+This guide explains how to add a new operator to yq. Operators are the core of yq's expression language and process `CandidateNode` objects without requiring modifications to `candidate_node.go` itself.
+
+## Overview
+
+Operators transform data by implementing a handler function that processes a `Context` containing `CandidateNode` objects. Each operator is:
+
+1. Defined as an `operationType` in `operation.go`
+2. Registered in the lexer in `lexer_participle.go`
+3. Implemented in its own `operator_<type>.go` file
+4. Tested in `operator_<type>_test.go`
+5. Documented in `pkg/yqlib/doc/operators/headers/<type>.md`
+
+## Architecture
+
+### Key Files
+
+- `pkg/yqlib/operation.go` - Defines `operationType` and operator registry
+- `pkg/yqlib/lexer_participle.go` - Registers operators with their syntax patterns
+- `pkg/yqlib/operator_<type>.go` - Operator implementation
+- `pkg/yqlib/operator_<type>_test.go` - Operator tests using `expressionScenario`
+- `pkg/yqlib/doc/operators/headers/<type>.md` - Documentation header
+
+### Core Types
+
+**operationType:**
+```go
+type operationType struct {
+    Type                 string          // Unique operator name (e.g., "REVERSE")
+    NumArgs              uint            // Number of arguments (0 for no args)
+    Precedence           uint            // Operator precedence (higher = higher precedence)
+    Handler              operatorHandler // The function that executes the operator
+    CheckForPostTraverse bool            // Whether to apply post-traversal logic
+    ToString             func(*Operation) string // Custom string representation
+}
+```
+
+**operatorHandler signature:**
+```go
+type operatorHandler func(*dataTreeNavigator, Context, *ExpressionNode) (Context, error)
+```
+
+**expressionScenario for tests:**
+```go
+type expressionScenario struct {
+    description      string
+    subdescription   string
+    document         string
+    expression       string
+    expected         []string
+    skipDoc          bool
+    expectedError    string
+}
+```
+
+## Step-by-Step: Adding a New Operator
+
+### Step 1: Create the Operator Implementation File
+
+Create `pkg/yqlib/operator_<type>.go` implementing the operator handler function:
+- Implement the `operatorHandler` function signature
+- Process nodes from `context.MatchingNodes`
+- Return a new `Context` with results using `context.ChildContext()`
+- Use `candidate.CreateReplacement()` or `candidate.CreateReplacementWithComments()` to create new nodes
+- Handle errors gracefully with meaningful error messages
+
+See `operator_reverse.go` or `operator_keys.go` for examples.
+
+### Step 2: Register the Operator in operation.go
+
+Add the operator type definition to `pkg/yqlib/operation.go`:
+
+```go
+var <type>OpType = &operationType{
+    Type:       "<TYPE>",          // All caps, matches pattern in lexer
+    NumArgs:    0,                 // 0 for no args, 1+ for args
+    Precedence: 50,                // Typical range: 40-55
+    Handler:    <type>Operator,    // Reference to handler function
+}
+```
+
+**Precedence guidelines:**
+- 10-20: Logical operators (OR, AND, UNION)
+- 30: Pipe operator
+- 40: Assignment and comparison operators
+- 42: Arithmetic operators (ADD, SUBTRACT, MULTIPLY, DIVIDE)
+- 50-52: Most other operators
+- 55: High precedence (e.g., GET_VARIABLE)
+
+**Optional fields:**
+- `CheckForPostTraverse: true` - If your operator can have another directly after it without the pipe character. Most of the time this is false.
+- `ToString: customToString` - Custom string representation (rarely needed)
+
+### Step 3: Register the Operator in lexer_participle.go
+
+Edit `pkg/yqlib/lexer_participle.go` to add the operator to the lexer rules:
+- Use `simpleOp()` for simple keyword patterns
+- Use object syntax for regex patterns or complex syntax
+- Support optional characters with `_?` and aliases with `|`
+
+See existing operators in `lexer_participle.go` for pattern examples.
+
+### Step 4: Create Tests (Mandatory)
+
+Create `pkg/yqlib/operator_<type>_test.go` using the `expressionScenario` pattern:
+- Define test scenarios with `description`, `document`, `expression`, and `expected` fields
+- `expected` is a slice of strings showing output format: `"D<doc>, P[<path>], (<tag>)::<value>\n"`
+- Set `skipDoc: true` for edge cases you don't want in generated documentation
+- Include `subdescription` for longer test names
+- Set `expectedError` if testing error cases
+- Create main test function that iterates over scenarios
+- The main test function should use `documentScenarios` to ensure testcase documentation is generated.
+
+Test coverage must include:
+- Basic data types and nested structures
+- Edge cases (empty inputs, special characters, type errors)
+- Multiple outputs if applicable
+- Format-specific features
+
+See `operator_reverse_test.go` for a simple example and `operator_keys_test.go` for complex cases.
+
+### Step 5: Create Documentation Header
+
+Create `pkg/yqlib/doc/operators/headers/<type>.md`:
+- Use the exact operator name as the title
+- Include a concise 1-2 sentence summary
+- Add additional context or examples if the operator is complex
+
+See existing headers in `doc/operators/headers/` for examples.
+
+## Working with Context and CandidateNode
+
+### Context Management
+- `context.ChildContext(results)` - Create child context with results
+- `context.GetVariable("varName")` - Get variables stored in context
+- `context.SetVariable("varName", value)` - Set variables in context
+
+### CandidateNode Operations
+- `candidate.CreateReplacement(ScalarNode, "!!str", stringValue)` - Create a replacement node
+- `candidate.CreateReplacementWithComments(SequenceNode, "!!seq", candidate.Style)` - With style preserved
+- `candidate.Kind` - The node type (ScalarNode, SequenceNode, MappingNode)
+- `candidate.Tag` - The YAML tag (!!str, !!int, etc.)
+- `candidate.Value` - The scalar value (for ScalarNode only)
+- `candidate.Content` - Child nodes (for SequenceNode and MappingNode)
+- `candidate.guessTagFromCustomType()` - Infer the tag from Go type
+- `candidate.AsList()` - Convert to a list representation
+
+## Key Points
+
+✅ **DO:**
+- Implement the operator handler with the correct signature
+- Register in `operation.go` with appropriate precedence
+- Add the lexer pattern in `lexer_participle.go`
+- Write comprehensive tests covering normal and edge cases
+- Create a documentation header in `doc/operators/headers/`
+- Use `Context.ChildContext()` for proper context threading
+- Handle all node types gracefully
+- Return meaningful error messages
+
+❌ **DON'T:**
+- Modify `candidate_node.go` (operators shouldn't need this)
+- Modify core navigation or evaluation logic
+- Bypass the handler function pattern
+- Add format-specific or operator-specific fields to `CandidateNode`
+- Skip tests or documentation
+
+## Examples
+
+Refer to existing operator implementations for patterns:
+
+- **No-argument operator**: `operator_reverse.go` - Processes arrays/sequences
+- **Single-argument operator**: `operator_map.go` - Takes an expression argument
+- **Complex multi-output**: `operator_keys.go` - Produces multiple results
+- **With preferences**: `operator_to_number.go` - Configuration options
+- **Error handling**: `operator_error.go` - Control flow with errors
+- **String operations**: `operator_strings.go` - Multiple related operators
+
+## Testing Patterns
+
+Refer to existing test files for specific patterns:
+- Basic expression tests in `operator_reverse_test.go`
+- Multi-output tests in `operator_keys_test.go`
+- Error handling tests in `operator_error_test.go`
+- Tests with `skipDoc` flag to exclude from generated documentation
+
+## Common Patterns
+
+Refer to existing operator implementations for these patterns:
+- Simple transformation: see `operator_reverse.go`
+- Type checking: see `operator_error.go`
+- Working with arguments: see `operator_map.go`
+- Post-traversal operators: see `operator_with.go`

cmd/evaluate_all_command.go

@@ -60,7 +60,7 @@ func evaluateAll(cmd *cobra.Command, args []string) (cmdError error) {
 	out := cmd.OutOrStdout()
 
 	if writeInplace {
-		// only use colors if its forced
+		// only use colours if its forced
 		colorsEnabled = forceColor
 		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[0])
 		out, err = writeInPlaceHandler.CreateTempFile()
@@ -101,12 +101,15 @@ func evaluateAll(cmd *cobra.Command, args []string) (cmdError error) {
 	}
 
 	if frontMatter != "" {
+		originalFilename := args[0]
 		frontMatterHandler := yqlib.NewFrontMatterHandler(args[0])
 		err = frontMatterHandler.Split()
 		if err != nil {
 			return err
 		}
 		args[0] = frontMatterHandler.GetYamlFrontMatterFilename()
+		yqlib.SetFilenameAlias(args[0], originalFilename)
+		defer yqlib.ClearFilenameAliases()
 
 		if frontMatter == "process" {
 			reader := frontMatterHandler.GetContentReader()

cmd/evaluate_all_command_test.go

@@ -13,6 +13,7 @@ func TestCreateEvaluateAllCommand(t *testing.T) {
 
 	if cmd == nil {
 		t.Fatal("createEvaluateAllCommand returned nil")
+		return
 	}
 
 	// Test basic command properties

cmd/evaluate_sequence_command.go

@@ -74,7 +74,7 @@ func evaluateSequence(cmd *cobra.Command, args []string) (cmdError error) {
 	}
 
 	if writeInplace {
-		// only use colors if its forced
+		// only use colours if its forced
 		colorsEnabled = forceColor
 		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[0])
 		out, err = writeInPlaceHandler.CreateTempFile()
@@ -122,12 +122,15 @@ func evaluateSequence(cmd *cobra.Command, args []string) (cmdError error) {
 
 	if frontMatter != "" {
 		yqlib.GetLogger().Debug("using front matter handler")
+		originalFilename := args[0]
 		frontMatterHandler := yqlib.NewFrontMatterHandler(args[0])
 		err = frontMatterHandler.Split()
 		if err != nil {
 			return err
 		}
 		args[0] = frontMatterHandler.GetYamlFrontMatterFilename()
+		yqlib.SetFilenameAlias(args[0], originalFilename)
+		defer yqlib.ClearFilenameAliases()
 
 		if frontMatter == "process" {
 			reader := frontMatterHandler.GetContentReader()

cmd/evaluate_sequence_command_test.go

@@ -13,6 +13,7 @@ func TestCreateEvaluateSequenceCommand(t *testing.T) {
 
 	if cmd == nil {
 		t.Fatal("createEvaluateSequenceCommand returned nil")
+		return
 	}
 
 	// Test basic command properties

cmd/root.go

@@ -2,12 +2,12 @@ package cmd
 
 import (
 	"fmt"
+	"log/slog"
 	"os"
 	"strings"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/spf13/cobra"
-	logging "gopkg.in/op/go-logging.v1"
 )
 
 type runeValue rune
@@ -68,30 +68,21 @@ yq -P -oy sample.json
 		},
 		PersistentPreRunE: func(cmd *cobra.Command, _ []string) error {
 			cmd.SetOut(cmd.OutOrStdout())
-			level := logging.WARNING
-			stringFormat := `[%{level}] %{color}%{time:15:04:05}%{color:reset} %{message}`
 
 			// when NO_COLOR environment variable presents and not an empty string the coloured output should be disabled;
 			// refer to no-color.org
 			forceNoColor = forceNoColor || os.Getenv("NO_COLOR") != ""
 
-			if verbose && forceNoColor {
-				level = logging.DEBUG
-				stringFormat = `[%{level:5.5s}] %{time:15:04:05} %{shortfile:-33s} %{shortfunc:-25s} %{message}`
-			} else if verbose {
-				level = logging.DEBUG
-				stringFormat = `[%{level:5.5s}] %{color}%{time:15:04:05}%{color:bold} %{shortfile:-33s} %{shortfunc:-25s}%{color:reset} %{message}`
-			} else if forceNoColor {
-				stringFormat = `[%{level}] %{time:15:04:05} %{message}`
+			level := slog.LevelWarn
+			if verbose {
+				level = slog.LevelDebug
 			}
 
-			var format = logging.MustStringFormatter(stringFormat)
-			var backend = logging.AddModuleLevel(
-				logging.NewBackendFormatter(logging.NewLogBackend(os.Stderr, "", 0), format))
+			yqlib.GetLogger().SetLevel(level)
+			opts := &slog.HandlerOptions{Level: level, AddSource: verbose}
+			handler := slog.NewTextHandler(os.Stderr, opts)
+			yqlib.GetLogger().SetSlogger(slog.New(handler))
 
-			backend.SetLevel(level, "")
-
-			logging.SetBackend(backend)
 			yqlib.InitExpressionParser()
 
 			return nil
@@ -184,7 +175,7 @@ yq -P -oy sample.json
 	}
 	rootCmd.Flags().BoolVarP(&version, "version", "V", false, "Print version information and quit")
 	rootCmd.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the file in place of first file given.")
-	rootCmd.PersistentFlags().VarP(unwrapScalarFlag, "unwrapScalar", "r", "unwrap scalar, print the value with no quotes, colors or comments. Defaults to true for yaml")
+	rootCmd.PersistentFlags().VarP(unwrapScalarFlag, "unwrapScalar", "r", "unwrap scalar, print the value with no quotes, colours or comments. Defaults to true for yaml")
 	rootCmd.PersistentFlags().Lookup("unwrapScalar").NoOptDefVal = "true"
 	rootCmd.PersistentFlags().BoolVarP(&nulSepOutput, "nul-output", "0", false, "Use NUL char to separate values. If unwrap scalar is also set, fail if unwrapped scalar contains NUL char.")
 
@@ -203,6 +194,7 @@ yq -P -oy sample.json
 	}
 	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredYamlPreferences.LeadingContentPreProcessing, "header-preprocess", "", true, "Slurp any header comments and separators before processing expression.")
 	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredYamlPreferences.FixMergeAnchorToSpec, "yaml-fix-merge-anchor-to-spec", "", false, "Fix merge anchor to match YAML spec. Will default to true in late 2025")
+	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredYamlPreferences.CompactSequenceIndent, "yaml-compact-seq-indent", "c", false, "Use compact sequence indentation where '- ' is considered part of the indentation.")
 
 	rootCmd.PersistentFlags().StringVarP(&splitFileExp, "split-exp", "s", "", "print each result (or doc) into a file named (exp). [exp] argument must return a string. You can use $index in the expression as the result counter. The necessary directories will be created.")
 	if err = rootCmd.RegisterFlagCompletionFunc("split-exp", cobra.NoFileCompletions); err != nil {
@@ -220,6 +212,7 @@ yq -P -oy sample.json
 
 	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredSecurityPreferences.DisableEnvOps, "security-disable-env-ops", "", false, "Disable env related operations.")
 	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredSecurityPreferences.DisableFileOps, "security-disable-file-ops", "", false, "Disable file related operations (e.g. load)")
+	rootCmd.PersistentFlags().BoolVarP(&yqlib.ConfiguredSecurityPreferences.EnableSystemOps, "security-enable-system-operator", "", false, "Enable system operator to allow execution of external commands.")
 
 	rootCmd.AddCommand(
 		createEvaluateSequenceCommand(),

cmd/root_test.go

@@ -195,6 +195,7 @@ func TestNew(t *testing.T) {
 
 	if rootCmd == nil {
 		t.Fatal("New() returned nil")
+		return
 	}
 
 	// Test basic command properties

cmd/utils.go

@@ -3,12 +3,12 @@ package cmd
 import (
 	"fmt"
 	"io"
+	"log/slog"
 	"os"
 	"strings"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/spf13/cobra"
-	"gopkg.in/op/go-logging.v1"
 )
 
 func isAutomaticOutputFormat() bool {
@@ -104,8 +104,8 @@ func configureFormats(args []string) error {
 		return err
 	}
 
-	yqlib.GetLogger().Debug("Using input format %v", inputFormat)
-	yqlib.GetLogger().Debug("Using output format %v", outputFormat)
+	yqlib.GetLogger().Debugf("Using input format %v", inputFormat)
+	yqlib.GetLogger().Debugf("Using output format %v", outputFormat)
 
 	return nil
 }
@@ -117,7 +117,7 @@ func configureInputFormat(inputFilename string) error {
 		_, err := yqlib.FormatFromString(inputFormat)
 		if err != nil {
 			// unknown file type, default to yaml
-			yqlib.GetLogger().Debug("Unknown file format extension '%v', defaulting to yaml", inputFormat)
+			yqlib.GetLogger().Debugf("Unknown file format extension '%v', defaulting to yaml", inputFormat)
 			inputFormat = "yaml"
 			if isAutomaticOutputFormat() {
 				outputFormat = "yaml"
@@ -132,7 +132,7 @@ func configureInputFormat(inputFilename string) error {
 		//
 		outputFormat = yqlib.FormatStringFromFilename(inputFilename)
 		if inputFilename != "-" {
-			yqlib.GetLogger().Warning("yq default output is now 'auto' (based on the filename extension). Normally yq would output '%v', but for backwards compatibility 'yaml' has been set. Please use -oy to specify yaml, or drop the -p flag.", outputFormat)
+			yqlib.GetLogger().Warningf("yq default output is now 'auto' (based on the filename extension). Normally yq would output '%v', but for backwards compatibility 'yaml' has been set. Please use -oy to specify yaml, or drop the -p flag.", outputFormat)
 		}
 		outputFormat = "yaml"
 	}
@@ -166,6 +166,9 @@ func configureDecoder(evaluateTogether bool) (yqlib.Decoder, error) {
 	}
 	yqlib.ConfiguredYamlPreferences.EvaluateTogether = evaluateTogether
 
+	if format.DecoderFactory == nil {
+		return nil, fmt.Errorf("no support for %s input format", inputFormat)
+	}
 	yqlibDecoder := format.DecoderFactory()
 	if yqlibDecoder == nil {
 		return nil, fmt.Errorf("no support for %s input format", inputFormat)
@@ -197,16 +200,23 @@ func configureEncoder() (yqlib.Encoder, error) {
 	}
 	yqlib.ConfiguredXMLPreferences.Indent = indent
 	yqlib.ConfiguredYamlPreferences.Indent = indent
+	yqlib.ConfiguredKYamlPreferences.Indent = indent
 	yqlib.ConfiguredJSONPreferences.Indent = indent
 
 	yqlib.ConfiguredYamlPreferences.UnwrapScalar = unwrapScalar
+	yqlib.ConfiguredKYamlPreferences.UnwrapScalar = unwrapScalar
 	yqlib.ConfiguredPropertiesPreferences.UnwrapScalar = unwrapScalar
 	yqlib.ConfiguredJSONPreferences.UnwrapScalar = unwrapScalar
+	yqlib.ConfiguredShellVariablesPreferences.UnwrapScalar = unwrapScalar
 
 	yqlib.ConfiguredYamlPreferences.ColorsEnabled = colorsEnabled
+	yqlib.ConfiguredKYamlPreferences.ColorsEnabled = colorsEnabled
 	yqlib.ConfiguredJSONPreferences.ColorsEnabled = colorsEnabled
+	yqlib.ConfiguredHclPreferences.ColorsEnabled = colorsEnabled
+	yqlib.ConfiguredTomlPreferences.ColorsEnabled = colorsEnabled
 
 	yqlib.ConfiguredYamlPreferences.PrintDocSeparators = !noDocSeparators
+	yqlib.ConfiguredKYamlPreferences.PrintDocSeparators = !noDocSeparators
 
 	encoder := yqlibOutputFormat.EncoderFactory()
 
@@ -225,7 +235,7 @@ func maybeFile(str string) bool {
 	yqlib.GetLogger().Debugf("checking '%v' is a file", str)
 	stat, err := os.Stat(str) // #nosec
 	result := err == nil && !stat.IsDir()
-	if yqlib.GetLogger().IsEnabledFor(logging.DEBUG) {
+	if yqlib.GetLogger().IsEnabledFor(slog.LevelDebug) {
 		if err != nil {
 			yqlib.GetLogger().Debugf("error: %v", err)
 		} else {
@@ -270,7 +280,7 @@ func processArgs(originalArgs []string) (string, []string, error) {
 
 	if expressionFile == "" && maybeFirstArgIsAFile && strings.HasSuffix(args[0], ".yq") {
 		// lets check if an expression file was given
-		yqlib.GetLogger().Debug("Assuming arg %v is an expression file", args[0])
+		yqlib.GetLogger().Debugf("Assuming arg %v is an expression file", args[0])
 		expressionFile = args[0]
 		args = args[1:]
 	}
@@ -286,7 +296,7 @@ func processArgs(originalArgs []string) (string, []string, error) {
 
 	yqlib.GetLogger().Debugf("processed args: %v", args)
 	if expression == "" && len(args) > 0 && args[0] != "-" && !maybeFile(args[0]) {
-		yqlib.GetLogger().Debug("assuming expression is '%v'", args[0])
+		yqlib.GetLogger().Debugf("assuming expression is '%v'", args[0])
 		expression = args[0]
 		args = args[1:]
 	}

cmd/utils_test.go

@@ -911,7 +911,7 @@ func stringsEqual(a, b []string) bool {
 		return false
 	}
 	for i := range a {
-		if a[i] != b[i] {
+		if a[i] != b[i] { //nolint:gosec // G602 false positive: b length equality is checked above
 			return false
 		}
 	}
@@ -926,13 +926,13 @@ func TestSetupColors(t *testing.T) {
 		expectColors bool
 	}{
 		{
-			name:         "force color enabled",
+			name:         "force colour enabled",
 			forceColor:   true,
 			forceNoColor: false,
 			expectColors: true,
 		},
 		{
-			name:         "force no color enabled",
+			name:         "force no colour enabled",
 			forceColor:   false,
 			forceNoColor: true,
 			expectColors: false,

cmd/version.go

@@ -11,7 +11,7 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "v4.49.2"
+	Version = "v4.52.5"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
 	// then it means that it is a final release. Otherwise, this is a pre-release

cmd/version_test.go

@@ -1,6 +1,9 @@
 package cmd
 
-import "testing"
+import (
+	"strings"
+	"testing"
+)
 
 func TestGetVersionDisplay(t *testing.T) {
 	var expectedVersion = ProductName + " (https://github.com/mikefarah/yq/) version " + Version
@@ -25,6 +28,18 @@ func TestGetVersionDisplay(t *testing.T) {
 }
 
 func Test_getHumanVersion(t *testing.T) {
+	// Save original values
+	origGitDescribe := GitDescribe
+	origGitCommit := GitCommit
+	origVersionPrerelease := VersionPrerelease
+
+	// Restore after test
+	defer func() {
+		GitDescribe = origGitDescribe
+		GitCommit = origGitCommit
+		VersionPrerelease = origVersionPrerelease
+	}()
+
 	GitDescribe = "e42813d"
 	GitCommit = "e42813d+CHANGES"
 	var wanted string
@@ -49,3 +64,118 @@ func Test_getHumanVersion(t *testing.T) {
 		}
 	}
 }
+
+func Test_getHumanVersion_NoGitDescribe(t *testing.T) {
+	// Save original values
+	origGitDescribe := GitDescribe
+	origGitCommit := GitCommit
+	origVersionPrerelease := VersionPrerelease
+
+	// Restore after test
+	defer func() {
+		GitDescribe = origGitDescribe
+		GitCommit = origGitCommit
+		VersionPrerelease = origVersionPrerelease
+	}()
+
+	GitDescribe = ""
+	GitCommit = ""
+	VersionPrerelease = ""
+
+	got := getHumanVersion()
+	if got != Version {
+		t.Errorf("getHumanVersion() = %v, want %v", got, Version)
+	}
+}
+
+func Test_getHumanVersion_WithPrerelease(t *testing.T) {
+	// Save original values
+	origGitDescribe := GitDescribe
+	origGitCommit := GitCommit
+	origVersionPrerelease := VersionPrerelease
+
+	// Restore after test
+	defer func() {
+		GitDescribe = origGitDescribe
+		GitCommit = origGitCommit
+		VersionPrerelease = origVersionPrerelease
+	}()
+
+	GitDescribe = ""
+	GitCommit = "abc123"
+	VersionPrerelease = "beta"
+
+	got := getHumanVersion()
+	expected := Version + "-beta (abc123)"
+	if got != expected {
+		t.Errorf("getHumanVersion() = %v, want %v", got, expected)
+	}
+}
+
+func Test_getHumanVersion_PrereleaseInVersion(t *testing.T) {
+	// Save original values
+	origGitDescribe := GitDescribe
+	origGitCommit := GitCommit
+	origVersionPrerelease := VersionPrerelease
+
+	// Restore after test
+	defer func() {
+		GitDescribe = origGitDescribe
+		GitCommit = origGitCommit
+		VersionPrerelease = origVersionPrerelease
+	}()
+
+	GitDescribe = "v1.2.3-rc1"
+	GitCommit = "xyz789"
+	VersionPrerelease = "rc1"
+
+	got := getHumanVersion()
+	// Should not duplicate "rc1" since it's already in GitDescribe
+	expected := "v1.2.3-rc1 (xyz789)"
+	if got != expected {
+		t.Errorf("getHumanVersion() = %v, want %v", got, expected)
+	}
+}
+
+func Test_getHumanVersion_StripSingleQuotes(t *testing.T) {
+	// Save original values
+	origGitDescribe := GitDescribe
+	origGitCommit := GitCommit
+	origVersionPrerelease := VersionPrerelease
+
+	// Restore after test
+	defer func() {
+		GitDescribe = origGitDescribe
+		GitCommit = origGitCommit
+		VersionPrerelease = origVersionPrerelease
+	}()
+
+	GitDescribe = "'v1.2.3'"
+	GitCommit = "'commit123'"
+	VersionPrerelease = ""
+
+	got := getHumanVersion()
+	// Should strip single quotes
+	if strings.Contains(got, "'") {
+		t.Errorf("getHumanVersion() = %v, should not contain single quotes", got)
+	}
+	expected := "v1.2.3"
+	if got != expected {
+		t.Errorf("getHumanVersion() = %v, want %v", got, expected)
+	}
+}
+
+func TestProductName(t *testing.T) {
+	if ProductName != "yq" {
+		t.Errorf("ProductName = %v, want yq", ProductName)
+	}
+}
+
+func TestVersionIsSet(t *testing.T) {
+	if Version == "" {
+		t.Error("Version should not be empty")
+	}
+	if !strings.HasPrefix(Version, "v") {
+		t.Errorf("Version %v should start with 'v'", Version)
+	}
+}

examples/kyaml.kyaml

@@ -0,0 +1,10 @@
+# leading
+{
+  a: 1, # a line
+  # head b
+  b: 2,
+  c: [
+    # head d
+    "d", # d line
+  ],
+}

examples/kyaml.yml

@@ -0,0 +1,7 @@
+# leading
+a: 1 # a line
+# head b
+b: 2
+c:
+  # head d
+  - d # d line

examples/sample.hcl

@@ -0,0 +1,8 @@
+# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+
+# String interpolation and templates
+message = "Hello, ${name}!"
+
+# Application-provided functions
+shouty_message = upper(message)

examples/sample.tf

@@ -0,0 +1,27 @@
+# main.tf
+
+# Define required providers and minimum Terraform version
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 5.0"
+    }
+  }
+  required_version = ">= 1.2"
+}
+
+# Configure the AWS provider
+provider "aws" {
+  region = var.aws_region
+}
+
+# Define an S3 bucket resource
+resource "aws_s3_bucket" "example_bucket" {
+  bucket = var.bucket_name
+
+  tags = {
+    Environment = "Development"
+    Project     = "TerraformExample"
+  }
+}

examples/sample.toml

@@ -1,6 +1,26 @@
-[[fruits]]
 
-[animals]
 
-[[fruits.varieties]]  # nested array of tables
-name = "red delicious"
+# This is a TOML document
+
+title = "TOML Example"
+
+[owner]
+name = "Tom Preston-Werner"
+dob = 1979-05-27T07:32:00-08:00
+
+[database]
+enabled = true
+ports = [ 8000, 8001, 8002 ]
+data = [ ["delta", "phi"], [3.14] ]
+temp_targets = { cpu = 79.5, case = 72.0 }
+
+[servers]
+
+[servers.alpha]
+ip = "10.0.0.1"
+role = "frontend"
+
+[servers.beta]
+ip = "10.0.0.2"
+role = "backend"
+

examples/sample2.hcl

@@ -0,0 +1,8 @@
+# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+
+# String interpolation and templates
+message = "Hello, ${name}!"
+
+# Application-provided functions
+shouty_message = upper(message)

github-action/Dockerfile

@@ -1,4 +1,4 @@
-FROM mikefarah/yq:4
+FROM mikefarah/yq:4@sha256:603ebff15eb308a05f1c5b8b7613179cad859aed3ec9fdd04f2ef5d32345950e
 
 COPY entrypoint.sh /entrypoint.sh
 

go.mod

@@ -6,30 +6,36 @@ require (
 	github.com/alecthomas/repr v0.5.2
 	github.com/dimchansky/utfbom v1.1.1
 	github.com/elliotchance/orderedmap v1.8.0
-	github.com/fatih/color v1.18.0
+	github.com/fatih/color v1.19.0
 	github.com/go-ini/ini v1.67.0
-	github.com/goccy/go-json v0.10.5
-	github.com/goccy/go-yaml v1.19.0
+	github.com/goccy/go-json v0.10.6
+	github.com/goccy/go-yaml v1.19.2
+	github.com/hashicorp/hcl/v2 v2.24.0
 	github.com/jinzhu/copier v0.4.0
 	github.com/magiconair/properties v1.8.10
-	github.com/pelletier/go-toml/v2 v2.2.4
+	github.com/pelletier/go-toml/v2 v2.3.0
 	github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/pflag v1.0.10
-	github.com/yuin/gopher-lua v1.1.1
-	go.yaml.in/yaml/v4 v4.0.0-rc.3
-	golang.org/x/net v0.47.0
-	golang.org/x/text v0.31.0
-	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
+	github.com/yuin/gopher-lua v1.1.2
+	github.com/zclconf/go-cty v1.18.0
+	go.yaml.in/yaml/v4 v4.0.0-rc.4
+	golang.org/x/mod v0.34.0
+	golang.org/x/net v0.52.0
+	golang.org/x/text v0.35.0
 )
 
 require (
+	github.com/agext/levenshtein v1.2.1 // indirect
+	github.com/apparentlymart/go-textseg/v15 v15.0.0 // indirect
+	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	golang.org/x/sys v0.38.0 // indirect
+	github.com/mitchellh/go-wordwrap v1.0.1 // indirect
+	golang.org/x/sync v0.20.0 // indirect
+	golang.org/x/sys v0.42.0 // indirect
+	golang.org/x/tools v0.42.0 // indirect
 )
 
-go 1.24.0
-
-toolchain go1.24.1
+go 1.25.0

go.sum

@@ -1,26 +1,37 @@
 github.com/a8m/envsubst v1.4.3 h1:kDF7paGK8QACWYaQo6KtyYBozY2jhQrTuNNuUxQkhJY=
 github.com/a8m/envsubst v1.4.3/go.mod h1:4jjHWQlZoaXPoLQUb7H2qT4iLkZDdmEQiOUogdUmqVU=
+github.com/agext/levenshtein v1.2.1 h1:QmvMAjj2aEICytGiWzmxoE0x2KZvE0fvmqMOfy2tjT8=
+github.com/agext/levenshtein v1.2.1/go.mod h1:JEDfjyjHDjOF/1e4FlBE/PkbqA9OfWu2ki2W0IB5558=
 github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8vS6K3D0=
 github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
 github.com/alecthomas/participle/v2 v2.1.4 h1:W/H79S8Sat/krZ3el6sQMvMaahJ+XcM9WSI2naI7w2U=
 github.com/alecthomas/participle/v2 v2.1.4/go.mod h1:8tqVbpTX20Ru4NfYQgZf4mP18eXPTBViyMWiArNEgGI=
 github.com/alecthomas/repr v0.5.2 h1:SU73FTI9D1P5UNtvseffFSGmdNci/O6RsqzeXJtP0Qs=
 github.com/alecthomas/repr v0.5.2/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/apparentlymart/go-textseg/v15 v15.0.0 h1:uYvfpb3DyLSCGWnctWKGj857c6ew1u1fNQOlOtuGxQY=
+github.com/apparentlymart/go-textseg/v15 v15.0.0/go.mod h1:K8XmNZdhEBkdlyDdvbmmsvpAG721bKi0joRfFdHIWJ4=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dimchansky/utfbom v1.1.1 h1:vV6w1AhK4VMnhBno/TPVCoK9U/LP0PkLCS9tbxHdi/U=
 github.com/dimchansky/utfbom v1.1.1/go.mod h1:SxdoEBH5qIqFocHMyGOXVAybYJdr71b1Q/j0mACtrfE=
 github.com/elliotchance/orderedmap v1.8.0 h1:TrOREecvh3JbS+NCgwposXG5ZTFHtEsQiCGOhPElnMw=
 github.com/elliotchance/orderedmap v1.8.0/go.mod h1:wsDwEaX5jEoyhbs7x93zk2H/qv0zwuhg4inXhDkYqys=
-github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
-github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
+github.com/fatih/color v1.19.0 h1:Zp3PiM21/9Ld6FzSKyL5c/BULoe/ONr9KlbYVOfG8+w=
+github.com/fatih/color v1.19.0/go.mod h1:zNk67I0ZUT1bEGsSGyCZYZNrHuTkJJB+r6Q9VuMi0LE=
 github.com/go-ini/ini v1.67.0 h1:z6ZrTEZqSWOTyH2FlglNbNgARyHG8oLW9gMELqKr06A=
 github.com/go-ini/ini v1.67.0/go.mod h1:ByCAeIL28uOIIG0E3PJtZPDL8WnHpFKFOtgjp+3Ies8=
-github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4=
-github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
-github.com/goccy/go-yaml v1.19.0 h1:EmkZ9RIsX+Uq4DYFowegAuJo8+xdX3T/2dwNPXbxEYE=
-github.com/goccy/go-yaml v1.19.0/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
+github.com/go-test/deep v1.0.3 h1:ZrJSEWsXzPOxaZnFteGEfooLba+ju3FYIbOrS+rQd68=
+github.com/go-test/deep v1.0.3/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
+github.com/goccy/go-json v0.10.6 h1:p8HrPJzOakx/mn/bQtjgNjdTcN+/S6FcG2CTtQOrHVU=
+github.com/goccy/go-json v0.10.6/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
+github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
+github.com/goccy/go-yaml v1.19.2/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/hashicorp/hcl/v2 v2.24.0 h1:2QJdZ454DSsYGoaE6QheQZjtKZSUs9Nh2izTWiwQxvE=
+github.com/hashicorp/hcl/v2 v2.24.0/go.mod h1:oGoO1FIQYfn/AgyOhlg9qLC6/nOJPX3qGbkZpYAcqfM=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -33,8 +44,10 @@ github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHP
 github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
-github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/mitchellh/go-wordwrap v1.0.1 h1:TLuKupo69TCn6TQSyGxwI1EblZZEsQ0vMlAFQflz0v0=
+github.com/mitchellh/go-wordwrap v1.0.1/go.mod h1:R62XHJLzvMFRBbcrT7m7WgmE1eOyTSsCt+hzestvNj0=
+github.com/pelletier/go-toml/v2 v2.3.0 h1:k59bC/lIZREW0/iVaQR8nDHxVq8OVlIzYCOJf421CaM=
+github.com/pelletier/go-toml/v2 v2.3.0/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e h1:aoZm08cpOy4WuID//EZDgcC4zIxODThtZNPirFr42+A=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -48,20 +61,28 @@ github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3A
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
-github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
+github.com/yuin/gopher-lua v1.1.2 h1:yF/FjE3hD65tBbt0VXLE13HWS9h34fdzJmrWRXwobGA=
+github.com/yuin/gopher-lua v1.1.2/go.mod h1:7aRmXIWl37SqRf0koeyylBEzJ+aPt8A+mmkQ4f1ntR8=
+github.com/zclconf/go-cty v1.18.0 h1:pJ8+HNI4gFoyRNqVE37wWbJWVw43BZczFo7KUoRczaA=
+github.com/zclconf/go-cty v1.18.0/go.mod h1:qpnV6EDNgC1sns/AleL1fvatHw72j+S+nS+MJ+T2CSg=
+github.com/zclconf/go-cty-debug v0.0.0-20240509010212-0d6042c53940 h1:4r45xpDWB6ZMSMNJFMOjqrGHynW3DIBuR2H9j0ug+Mo=
+github.com/zclconf/go-cty-debug v0.0.0-20240509010212-0d6042c53940/go.mod h1:CmBdvvj3nqzfzJ6nTCIwDTPZ56aVGvDrmztiO5g3qrM=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-go.yaml.in/yaml/v4 v4.0.0-rc.3 h1:3h1fjsh1CTAPjW7q/EMe+C8shx5d8ctzZTrLcs/j8Go=
-go.yaml.in/yaml/v4 v4.0.0-rc.3/go.mod h1:aZqd9kCMsGL7AuUv/m/PvWLdg5sjJsZ4oHDEnfPPfY0=
-golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
-golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
+go.yaml.in/yaml/v4 v4.0.0-rc.4 h1:UP4+v6fFrBIb1l934bDl//mmnoIZEDK0idg1+AIvX5U=
+go.yaml.in/yaml/v4 v4.0.0-rc.4/go.mod h1:aZqd9kCMsGL7AuUv/m/PvWLdg5sjJsZ4oHDEnfPPfY0=
+golang.org/x/mod v0.34.0 h1:xIHgNUUnW6sYkcM5Jleh05DvLOtwc6RitGHbDk4akRI=
+golang.org/x/mod v0.34.0/go.mod h1:ykgH52iCZe79kzLLMhyCUzhMci+nQj+0XkbXpNYtVjY=
+golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
+golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
-golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/text v0.31.0 h1:aC8ghyu4JhP8VojJ2lEHBnochRno1sgL6nEi9WGFGMM=
-golang.org/x/text v0.31.0/go.mod h1:tKRAlv61yKIjGGHX/4tP1LTbc13YSec1pxVEWXzfoeM=
+golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
+golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
+golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
+golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
+golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473 h1:6D+BvnJ/j6e222UW8s2qTSe3wGBtvo0MbVQG/c5k8RE=
-gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473/go.mod h1:N1eN2tsCx0Ydtgjl4cqmbRCsY4/+z4cYDeqwZTk6zog=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

go_install_test.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"io"
+	"testing"
+
+	"golang.org/x/mod/module"
+	"golang.org/x/mod/zip"
+)
+
+// TestGoInstallCompatibility ensures the module can be zipped for go install.
+// This is an integration test that uses the same zip.CreateFromDir function
+// that go install uses internally. If this test fails, go install will fail.
+// See: https://github.com/mikefarah/yq/issues/2587
+func TestGoInstallCompatibility(t *testing.T) {
+	mod := module.Version{
+		Path:    "github.com/mikefarah/yq/v4",
+		Version: "v4.0.0", // the actual version doesn't matter for validation
+	}
+
+	if err := zip.CreateFromDir(io.Discard, mod, "."); err != nil {
+		t.Fatalf("Module cannot be zipped for go install: %v", err)
+	}
+}

pkg/yqlib/all_at_once_evaluator_test.go

@@ -54,3 +54,25 @@ func TestAllAtOnceEvaluateNodes(t *testing.T) {
 		test.AssertResultComplex(t, tt.expected, resultsToString(t, list))
 	}
 }
+
+func TestTomlDecoderCanBeReinitializedAcrossDocuments(t *testing.T) {
+	decoder := NewTomlDecoder()
+
+	firstDocuments, err := ReadDocuments(strings.NewReader("id = \"Foobar\"\n"), decoder)
+	if err != nil {
+		t.Fatalf("failed to read first TOML document: %v", err)
+	}
+	if firstDocuments.Len() != 1 {
+		t.Fatalf("expected first document count to be 1, got %d", firstDocuments.Len())
+	}
+	test.AssertResult(t, "Foobar", firstDocuments.Front().Value.(*CandidateNode).Content[1].Value)
+
+	secondDocuments, err := ReadDocuments(strings.NewReader("id = \"Banana\"\n"), decoder)
+	if err != nil {
+		t.Fatalf("failed to read second TOML document: %v", err)
+	}
+	if secondDocuments.Len() != 1 {
+		t.Fatalf("expected second document count to be 1, got %d", secondDocuments.Len())
+	}
+	test.AssertResult(t, "Banana", secondDocuments.Front().Value.(*CandidateNode).Content[1].Value)
+}

pkg/yqlib/candidate_node.go

@@ -27,6 +27,22 @@ const (
 	FlowStyle
 )
 
+// EncodeHint controls how a mapping node is serialised by format-specific encoders
+// that distinguish between inline and block/section representations (e.g. TOML, HCL).
+type EncodeHint int
+
+const (
+	// EncodeHintDefault lets the encoder choose the representation (e.g. TOML block
+	// mappings default to [section] headers).
+	EncodeHintDefault EncodeHint = iota
+	// EncodeHintSeparateBlock forces the node to be emitted as a separate block or
+	// table-section header (used by TOML [section] and HCL block decoders).
+	EncodeHintSeparateBlock
+	// EncodeHintInline forces the node to be emitted as an inline / flow table
+	// (used by TOML inline-table decoder and TOML encoder).
+	EncodeHintInline
+)
+
 func createStringScalarNode(stringValue string) *CandidateNode {
 	var node = &CandidateNode{Kind: ScalarNode}
 	node.Value = stringValue
@@ -97,6 +113,9 @@ type CandidateNode struct {
 	// (e.g. top level cross document merge). This property does not propagate to child nodes.
 	EvaluateTogether bool
 	IsMapKey         bool
+	// EncodeHint controls how a mapping node is serialised by format-specific encoders
+	// (e.g. TOML, HCL) that support both inline and block/section representations.
+	EncodeHint EncodeHint
 }
 
 func (n *CandidateNode) CreateChild() *CandidateNode {
@@ -277,7 +296,7 @@ func (n *CandidateNode) AddChild(rawChild *CandidateNode) {
 
 func (n *CandidateNode) AddChildren(children []*CandidateNode) {
 	if n.Kind == MappingNode {
-		for i := 0; i < len(children); i += 2 {
+		for i := 0; i < len(children)-1; i += 2 {
 			key := children[i]
 			value := children[i+1]
 			n.AddKeyValueChild(key, value)
@@ -320,11 +339,11 @@ func (n *CandidateNode) guessTagFromCustomType() string {
 	dataBucket, errorReading := parseSnippet(n.Value)
 
 	if errorReading != nil {
-		log.Debug("guessTagFromCustomType: could not guess underlying tag type %v", errorReading)
+		log.Debugf("guessTagFromCustomType: could not guess underlying tag type %v", errorReading)
 		return n.Tag
 	}
 	guessedTag := dataBucket.Tag
-	log.Info("im guessing the tag %v is a %v", n.Tag, guessedTag)
+	log.Infof("im guessing the tag %v is a %v", n.Tag, guessedTag)
 	return guessedTag
 }
 
@@ -407,6 +426,8 @@ func (n *CandidateNode) doCopy(cloneContent bool) *CandidateNode {
 
 		EvaluateTogether: n.EvaluateTogether,
 		IsMapKey:         n.IsMapKey,
+
+		EncodeHint: n.EncodeHint,
 	}
 
 	if cloneContent {
@@ -440,7 +461,7 @@ func (n *CandidateNode) UpdateFrom(other *CandidateNode, prefs assignPreferences
 }
 
 func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode, prefs assignPreferences) {
-	log.Debug("UpdateAttributesFrom: n: %v other: %v", NodeToString(n), NodeToString(other))
+	log.Debugf("UpdateAttributesFrom: n: %v other: %v", NodeToString(n), NodeToString(other))
 	if n.Kind != other.Kind {
 		// clear out the contents when switching to a different type
 		// e.g. map to array
@@ -460,6 +481,9 @@ func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode, prefs assignP
 		n.Anchor = other.Anchor
 	}
 
+	// Preserve EncodeHint for format-specific encoding hints
+	n.EncodeHint = other.EncodeHint
+
 	// merge will pickup the style of the new thing
 	// when autocreating nodes
 

pkg/yqlib/candidate_node_goccy_yaml.go

@@ -36,13 +36,13 @@ func (o *CandidateNode) UnmarshalGoccyYAML(node ast.Node, cm yaml.CommentMap, an
 					switch commentMapComment.Position {
 					case yaml.CommentHeadPosition:
 						o.HeadComment = comment.String()
-						log.Debug("its a head comment %v", comment.String())
+						log.Debugf("its a head comment %v", comment.String())
 					case yaml.CommentLinePosition:
 						o.LineComment = comment.String()
-						log.Debug("its a line comment %v", comment.String())
+						log.Debugf("its a line comment %v", comment.String())
 					case yaml.CommentFootPosition:
 						o.FootComment = comment.String()
-						log.Debug("its a foot comment %v", comment.String())
+						log.Debugf("its a foot comment %v", comment.String())
 					}
 				}
 			}
@@ -93,8 +93,8 @@ func (o *CandidateNode) UnmarshalGoccyYAML(node ast.Node, cm yaml.CommentMap, an
 			log.Debugf("folded Type %v", astLiteral.Start.Type)
 			o.Style = FoldedStyle
 		}
-		log.Debug("start value: %v ", node.(*ast.LiteralNode).Start.Value)
-		log.Debug("start value: %v ", node.(*ast.LiteralNode).Start.Type)
+		log.Debugf("start value: %v ", node.(*ast.LiteralNode).Start.Value)
+		log.Debugf("start value: %v ", node.(*ast.LiteralNode).Start.Type)
 		// TODO: here I could put the original value with line breaks
 		// to solve the multiline > problem
 		o.Value = astLiteral.Value.Value
@@ -187,7 +187,7 @@ func (o *CandidateNode) UnmarshalGoccyYAML(node ast.Node, cm yaml.CommentMap, an
 }
 
 func (o *CandidateNode) goccyProcessMappingValueNode(mappingEntry *ast.MappingValueNode, cm yaml.CommentMap, anchorMap map[string]*CandidateNode) error {
-	log.Debug("UnmarshalYAML MAP KEY entry %v", mappingEntry.Key)
+	log.Debugf("UnmarshalYAML MAP KEY entry %v", mappingEntry.Key)
 
 	// AddKeyValueFirst because it clones the nodes, and we want to have the real refs when Unmarshalling
 	// particularly for the anchorMap
@@ -197,7 +197,7 @@ func (o *CandidateNode) goccyProcessMappingValueNode(mappingEntry *ast.MappingVa
 		return err
 	}
 
-	log.Debug("UnmarshalYAML MAP VALUE entry %v", mappingEntry.Value)
+	log.Debugf("UnmarshalYAML MAP VALUE entry %v", mappingEntry.Value)
 	if err := valueNode.UnmarshalGoccyYAML(mappingEntry.Value, cm, anchorMap); err != nil {
 		return err
 	}

pkg/yqlib/candidate_node_json.go

@@ -120,7 +120,7 @@ func (o *CandidateNode) UnmarshalJSON(data []byte) error {
 	if err != nil {
 		return err
 	}
-	log.Debug("UnmarshalJSON -  scalar is %v", scalar)
+	log.Debugf("UnmarshalJSON -  scalar is %v", scalar)
 
 	return o.setScalarFromJson(scalar)
 

pkg/yqlib/candidate_node_yaml.go

@@ -55,13 +55,13 @@ func (o *CandidateNode) copyFromYamlNode(node *yaml.Node, anchorMap map[string]*
 
 	if o.Anchor != "" {
 		anchorMap[o.Anchor] = o
-		log.Debug("set anchor %v to %v", o.Anchor, NodeToString(o))
+		log.Debugf("set anchor %v to %v", o.Anchor, NodeToString(o))
 	}
 
 	// its a single alias
 	if node.Alias != nil && node.Alias.Anchor != "" {
 		o.Alias = anchorMap[node.Alias.Anchor]
-		log.Debug("set alias to %v", NodeToString(anchorMap[node.Alias.Anchor]))
+		log.Debugf("set alias to %v", NodeToString(anchorMap[node.Alias.Anchor]))
 	}
 	o.HeadComment = node.HeadComment
 	o.LineComment = node.LineComment
@@ -106,7 +106,7 @@ func (o *CandidateNode) UnmarshalYAML(node *yaml.Node, anchorMap map[string]*Can
 	log.Debugf("UnmarshalYAML %v", node.Tag)
 	switch node.Kind {
 	case yaml.AliasNode:
-		log.Debug("UnmarshalYAML - alias from yaml: %v", o.Tag)
+		log.Debugf("UnmarshalYAML - alias from yaml: %v", o.Tag)
 		o.Kind = AliasNode
 		o.copyFromYamlNode(node, anchorMap)
 		return nil
@@ -176,15 +176,15 @@ func (o *CandidateNode) UnmarshalYAML(node *yaml.Node, anchorMap map[string]*Can
 }
 
 func (o *CandidateNode) MarshalYAML() (*yaml.Node, error) {
-	log.Debug("MarshalYAML to yaml: %v", o.Tag)
+	log.Debugf("MarshalYAML to yaml: %v", o.Tag)
 	switch o.Kind {
 	case AliasNode:
-		log.Debug("MarshalYAML - alias to yaml: %v", o.Tag)
+		log.Debugf("MarshalYAML - alias to yaml: %v", o.Tag)
 		target := &yaml.Node{Kind: yaml.AliasNode}
 		o.copyToYamlNode(target)
 		return target, nil
 	case ScalarNode:
-		log.Debug("MarshalYAML - scalar: %v", o.Value)
+		log.Debugf("MarshalYAML - scalar: %v", o.Value)
 		target := &yaml.Node{Kind: yaml.ScalarNode}
 		o.copyToYamlNode(target)
 		return target, nil

pkg/yqlib/chown_linux.go

@@ -18,7 +18,7 @@ func changeOwner(info fs.FileInfo, file *os.File) error {
 			// this happens with snap confinement
 			// not really a big issue as users can chown
 			// the file themselves if required.
-			log.Info("Skipping chown: %v", err)
+			log.Infof("Skipping chown: %v", err)
 		}
 	}
 	return nil

pkg/yqlib/context.go

@@ -3,9 +3,8 @@ package yqlib
 import (
 	"container/list"
 	"fmt"
+	"log/slog"
 	"time"
-
-	logging "gopkg.in/op/go-logging.v1"
 )
 
 type Context struct {
@@ -75,7 +74,7 @@ func (n *Context) ChildContext(results *list.List) Context {
 }
 
 func (n *Context) ToString() string {
-	if !log.IsEnabledFor(logging.DEBUG) {
+	if !log.IsEnabledFor(slog.LevelDebug) {
 		return ""
 	}
 	result := fmt.Sprintf("Context\nDontAutoCreate: %v\n", n.DontAutoCreate)

pkg/yqlib/context_test.go

@@ -2,11 +2,11 @@ package yqlib
 
 import (
 	"container/list"
+	"log/slog"
 	"strings"
 	"testing"
 
 	"github.com/mikefarah/yq/v4/test"
-	logging "gopkg.in/op/go-logging.v1"
 )
 
 func TestChildContext(t *testing.T) {
@@ -155,8 +155,8 @@ func TestToString(t *testing.T) {
 	test.AssertResultComplex(t, "", result)
 
 	// Test with debug logging enabled
-	logging.SetLevel(logging.DEBUG, "")
-	defer logging.SetLevel(logging.INFO, "") // Reset to default
+	GetLogger().SetLevel(slog.LevelDebug)
+	defer GetLogger().SetLevel(slog.LevelWarn) // Reset to default
 
 	result2 := context.ToString()
 	test.AssertResultComplex(t, true, len(result2) > 0)

pkg/yqlib/data_tree_navigator.go

@@ -2,8 +2,7 @@ package yqlib
 
 import (
 	"fmt"
-
-	logging "gopkg.in/op/go-logging.v1"
+	"log/slog"
 )
 
 type DataTreeNavigator interface {
@@ -55,7 +54,7 @@ func (d *dataTreeNavigator) GetMatchingNodes(context Context, expressionNode *Ex
 		return context, nil
 	}
 	log.Debugf("Processing Op: %v", expressionNode.Operation.toString())
-	if log.IsEnabledFor(logging.DEBUG) {
+	if log.IsEnabledFor(slog.LevelDebug) {
 		for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 			log.Debug(NodeToString(el.Value.(*CandidateNode)))
 		}

pkg/yqlib/decoder_hcl.go

@@ -0,0 +1,471 @@
+//go:build !yq_nohcl
+
+package yqlib
+
+import (
+	"fmt"
+	"io"
+	"math/big"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+	"github.com/zclconf/go-cty/cty"
+)
+
+type hclDecoder struct {
+	file          *hcl.File
+	fileBytes     []byte
+	readAnything  bool
+	documentIndex uint
+}
+
+func NewHclDecoder() Decoder {
+	return &hclDecoder{}
+}
+
+// sortedAttributes returns attributes in declaration order by source position
+func sortedAttributes(attrs hclsyntax.Attributes) []*attributeWithName {
+	var sorted []*attributeWithName
+	for name, attr := range attrs {
+		sorted = append(sorted, &attributeWithName{Name: name, Attr: attr})
+	}
+	sort.Slice(sorted, func(i, j int) bool {
+		return sorted[i].Attr.Range().Start.Byte < sorted[j].Attr.Range().Start.Byte
+	})
+	return sorted
+}
+
+type attributeWithName struct {
+	Name string
+	Attr *hclsyntax.Attribute
+}
+
+// extractLineComment extracts any inline comment after the given position
+func extractLineComment(src []byte, endPos int) string {
+	// Look for # comment after the token
+	for i := endPos; i < len(src); i++ {
+		if src[i] == '#' {
+			// Found comment, extract until end of line
+			start := i
+			for i < len(src) && src[i] != '\n' {
+				i++
+			}
+			return strings.TrimSpace(string(src[start:i]))
+		}
+		if src[i] == '\n' {
+			// Hit newline before comment
+			break
+		}
+		// Skip whitespace and other characters
+	}
+	return ""
+}
+
+// extractHeadComment extracts comments before a given start position
+func extractHeadComment(src []byte, startPos int) string {
+	var comments []string
+
+	// Start just before the token and skip trailing whitespace
+	i := startPos - 1
+	for i >= 0 && (src[i] == ' ' || src[i] == '\t' || src[i] == '\n' || src[i] == '\r') {
+		i--
+	}
+
+	for i >= 0 {
+		// Find line boundaries
+		lineEnd := i
+		for i >= 0 && src[i] != '\n' {
+			i--
+		}
+		lineStart := i + 1
+
+		line := strings.TrimRight(string(src[lineStart:lineEnd+1]), " \t\r")
+		trimmed := strings.TrimSpace(line)
+
+		if trimmed == "" {
+			break
+		}
+
+		if !strings.HasPrefix(trimmed, "#") {
+			break
+		}
+
+		comments = append([]string{trimmed}, comments...)
+
+		// Move to previous line (skip any whitespace/newlines)
+		i = lineStart - 1
+		for i >= 0 && (src[i] == ' ' || src[i] == '\t' || src[i] == '\n' || src[i] == '\r') {
+			i--
+		}
+	}
+
+	if len(comments) > 0 {
+		return strings.Join(comments, "\n")
+	}
+	return ""
+}
+
+func (dec *hclDecoder) Init(reader io.Reader) error {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return err
+	}
+	file, diags := hclsyntax.ParseConfig(data, "input.hcl", hcl.Pos{Line: 1, Column: 1})
+	if diags != nil && diags.HasErrors() {
+		return fmt.Errorf("hcl parse error: %w", diags)
+	}
+	dec.file = file
+	dec.fileBytes = data
+	dec.readAnything = false
+	dec.documentIndex = 0
+	return nil
+}
+
+func (dec *hclDecoder) Decode() (*CandidateNode, error) {
+	if dec.readAnything {
+		return nil, io.EOF
+	}
+	dec.readAnything = true
+
+	if dec.file == nil {
+		return nil, fmt.Errorf("no hcl file parsed")
+	}
+
+	root := &CandidateNode{Kind: MappingNode}
+
+	// process attributes in declaration order
+	body := dec.file.Body.(*hclsyntax.Body)
+	firstAttr := true
+	for _, attrWithName := range sortedAttributes(body.Attributes) {
+		keyNode := createStringScalarNode(attrWithName.Name)
+		valNode := convertHclExprToNode(attrWithName.Attr.Expr, dec.fileBytes)
+
+		// Attach comments if any
+		attrRange := attrWithName.Attr.Range()
+		headComment := extractHeadComment(dec.fileBytes, attrRange.Start.Byte)
+		if firstAttr && headComment != "" {
+			// For the first attribute, apply its head comment to the root
+			root.HeadComment = headComment
+			firstAttr = false
+		} else if headComment != "" {
+			keyNode.HeadComment = headComment
+		}
+		if lineComment := extractLineComment(dec.fileBytes, attrRange.End.Byte); lineComment != "" {
+			valNode.LineComment = lineComment
+		}
+
+		root.AddKeyValueChild(keyNode, valNode)
+	}
+
+	// process blocks
+	// Count blocks by type at THIS level to detect multiple separate blocks
+	blocksByType := make(map[string]int)
+	for _, block := range body.Blocks {
+		blocksByType[block.Type]++
+	}
+
+	for _, block := range body.Blocks {
+		addBlockToMapping(root, block, dec.fileBytes, blocksByType[block.Type] > 1)
+	}
+
+	dec.documentIndex++
+	root.document = dec.documentIndex - 1
+	return root, nil
+}
+
+func hclBodyToNode(body *hclsyntax.Body, src []byte) *CandidateNode {
+	node := &CandidateNode{Kind: MappingNode}
+	for _, attrWithName := range sortedAttributes(body.Attributes) {
+		key := createStringScalarNode(attrWithName.Name)
+		val := convertHclExprToNode(attrWithName.Attr.Expr, src)
+
+		// Attach comments if any
+		attrRange := attrWithName.Attr.Range()
+		if headComment := extractHeadComment(src, attrRange.Start.Byte); headComment != "" {
+			key.HeadComment = headComment
+		}
+		if lineComment := extractLineComment(src, attrRange.End.Byte); lineComment != "" {
+			val.LineComment = lineComment
+		}
+
+		node.AddKeyValueChild(key, val)
+	}
+
+	// Process nested blocks, counting blocks by type at THIS level
+	// to detect which block types appear multiple times
+	blocksByType := make(map[string]int)
+	for _, block := range body.Blocks {
+		blocksByType[block.Type]++
+	}
+
+	for _, block := range body.Blocks {
+		addBlockToMapping(node, block, src, blocksByType[block.Type] > 1)
+	}
+	return node
+}
+
+// addBlockToMapping nests block type and labels into the parent mapping, merging children.
+// isMultipleBlocksOfType indicates if there are multiple blocks of this type at THIS level
+func addBlockToMapping(parent *CandidateNode, block *hclsyntax.Block, src []byte, isMultipleBlocksOfType bool) {
+	bodyNode := hclBodyToNode(block.Body, src)
+	current := parent
+
+	// ensure block type mapping exists
+	var typeNode *CandidateNode
+	for i := 0; i < len(current.Content); i += 2 {
+		if current.Content[i].Value == block.Type {
+			typeNode = current.Content[i+1]
+			break
+		}
+	}
+	if typeNode == nil {
+		_, typeNode = current.AddKeyValueChild(createStringScalarNode(block.Type), &CandidateNode{Kind: MappingNode})
+		// Mark the type node if there are multiple blocks of this type at this level
+		// This tells the encoder to emit them as separate blocks rather than consolidating them
+		if isMultipleBlocksOfType {
+			typeNode.EncodeHint = EncodeHintSeparateBlock
+		}
+	}
+	current = typeNode
+
+	// walk labels, creating/merging mappings
+	for _, label := range block.Labels {
+		var next *CandidateNode
+		for i := 0; i < len(current.Content); i += 2 {
+			if current.Content[i].Value == label {
+				next = current.Content[i+1]
+				break
+			}
+		}
+		if next == nil {
+			_, next = current.AddKeyValueChild(createStringScalarNode(label), &CandidateNode{Kind: MappingNode})
+		}
+		current = next
+	}
+
+	// merge body attributes/blocks into the final mapping
+	for i := 0; i < len(bodyNode.Content); i += 2 {
+		current.AddKeyValueChild(bodyNode.Content[i], bodyNode.Content[i+1])
+	}
+}
+
+func convertHclExprToNode(expr hclsyntax.Expression, src []byte) *CandidateNode {
+	// handle literal values directly
+	switch e := expr.(type) {
+	case *hclsyntax.LiteralValueExpr:
+		v := e.Val
+		if v.IsNull() {
+			return createScalarNode(nil, "")
+		}
+		switch {
+		case v.Type().Equals(cty.String):
+			// prefer to extract exact source (to avoid extra quoting) when available
+			// Prefer the actual cty string value
+			s := v.AsString()
+			node := createScalarNode(s, s)
+			// Don't set style for regular quoted strings - let YAML handle naturally
+			return node
+		case v.Type().Equals(cty.Bool):
+			b := v.True()
+			return createScalarNode(b, strconv.FormatBool(b))
+		case v.Type() == cty.Number:
+			// prefer integers when the numeric value is integral
+			bf := v.AsBigFloat()
+			if bf == nil {
+				// fallback to string
+				return createStringScalarNode(v.GoString())
+			}
+			// check if bf represents an exact integer
+			if intVal, acc := bf.Int(nil); acc == big.Exact {
+				s := intVal.String()
+				return createScalarNode(intVal.Int64(), s)
+			}
+			s := bf.Text('g', -1)
+			return createScalarNode(0.0, s)
+		case v.Type().IsTupleType() || v.Type().IsListType() || v.Type().IsSetType():
+			seq := &CandidateNode{Kind: SequenceNode}
+			it := v.ElementIterator()
+			for it.Next() {
+				_, val := it.Element()
+				// convert cty.Value to a node by wrapping in literal expr via string representation
+				child := convertCtyValueToNode(val)
+				seq.AddChild(child)
+			}
+			return seq
+		case v.Type().IsMapType() || v.Type().IsObjectType():
+			m := &CandidateNode{Kind: MappingNode}
+			it := v.ElementIterator()
+			for it.Next() {
+				key, val := it.Element()
+				keyStr := key.AsString()
+				keyNode := createStringScalarNode(keyStr)
+				valNode := convertCtyValueToNode(val)
+				m.AddKeyValueChild(keyNode, valNode)
+			}
+			return m
+		default:
+			// fallback to string
+			s := v.GoString()
+			return createStringScalarNode(s)
+		}
+	case *hclsyntax.TupleConsExpr:
+		// parse tuple/list into YAML sequence
+		seq := &CandidateNode{Kind: SequenceNode}
+		for _, exprVal := range e.Exprs {
+			child := convertHclExprToNode(exprVal, src)
+			seq.AddChild(child)
+		}
+		return seq
+	case *hclsyntax.ObjectConsExpr:
+		// parse object into YAML mapping
+		m := &CandidateNode{Kind: MappingNode}
+		m.Style = FlowStyle // Mark as inline object (flow style) for encoder
+		for _, item := range e.Items {
+			// evaluate key expression to get the key string
+			keyVal, keyDiags := item.KeyExpr.Value(nil)
+			if keyDiags != nil && keyDiags.HasErrors() {
+				// fallback: try to extract key from source
+				r := item.KeyExpr.Range()
+				start := r.Start.Byte
+				end := r.End.Byte
+				if start >= 0 && end >= start && end <= len(src) {
+					keyNode := createStringScalarNode(strings.TrimSpace(string(src[start:end])))
+					valNode := convertHclExprToNode(item.ValueExpr, src)
+					m.AddKeyValueChild(keyNode, valNode)
+				}
+				continue
+			}
+			keyStr := keyVal.AsString()
+			keyNode := createStringScalarNode(keyStr)
+			valNode := convertHclExprToNode(item.ValueExpr, src)
+			m.AddKeyValueChild(keyNode, valNode)
+		}
+		return m
+	case *hclsyntax.TemplateExpr:
+		// Reconstruct template string, preserving ${} syntax for interpolations
+		var parts []string
+		for _, p := range e.Parts {
+			switch lp := p.(type) {
+			case *hclsyntax.LiteralValueExpr:
+				if lp.Val.Type().Equals(cty.String) {
+					parts = append(parts, lp.Val.AsString())
+				} else {
+					parts = append(parts, lp.Val.GoString())
+				}
+			default:
+				// Non-literal expression - reconstruct with ${} wrapper
+				r := p.Range()
+				start := r.Start.Byte
+				end := r.End.Byte
+				if start >= 0 && end >= start && end <= len(src) {
+					exprText := string(src[start:end])
+					parts = append(parts, "${"+exprText+"}")
+				} else {
+					parts = append(parts, fmt.Sprintf("${%v}", p))
+				}
+			}
+		}
+		combined := strings.Join(parts, "")
+		node := createScalarNode(combined, combined)
+		// Set DoubleQuotedStyle for all templates (which includes all quoted strings in HCL)
+		// This ensures HCL roundtrips preserve quotes, and YAML properly quotes strings with ${}
+		node.Style = DoubleQuotedStyle
+		return node
+	case *hclsyntax.ScopeTraversalExpr:
+		// Simple identifier/traversal (e.g. unquoted string literal in HCL)
+		r := e.Range()
+		start := r.Start.Byte
+		end := r.End.Byte
+		if start >= 0 && end >= start && end <= len(src) {
+			text := strings.TrimSpace(string(src[start:end]))
+			return createStringScalarNode(text)
+		}
+		// Fallback to root name if source unavailable
+		if len(e.Traversal) > 0 {
+			if root, ok := e.Traversal[0].(hcl.TraverseRoot); ok {
+				return createStringScalarNode(root.Name)
+			}
+		}
+		return createStringScalarNode("")
+	case *hclsyntax.FunctionCallExpr:
+		// Preserve function calls as raw expressions for roundtrip
+		r := e.Range()
+		start := r.Start.Byte
+		end := r.End.Byte
+		if start >= 0 && end >= start && end <= len(src) {
+			text := strings.TrimSpace(string(src[start:end]))
+			node := createStringScalarNode(text)
+			node.Style = 0
+			return node
+		}
+		node := createStringScalarNode(e.Name)
+		node.Style = 0
+		return node
+	default:
+		// try to evaluate the expression (handles unary, binary ops, etc.)
+		val, diags := expr.Value(nil)
+		if diags == nil || !diags.HasErrors() {
+			// successfully evaluated, convert cty.Value to node
+			return convertCtyValueToNode(val)
+		}
+		// fallback: extract source text for the expression
+		r := expr.Range()
+		start := r.Start.Byte
+		end := r.End.Byte
+		if start >= 0 && end >= start && end <= len(src) {
+			text := string(src[start:end])
+			// Mark as unquoted expression so encoder emits without quoting
+			node := createStringScalarNode(text)
+			node.Style = 0
+			return node
+		}
+		return createStringScalarNode(fmt.Sprintf("%v", expr))
+	}
+}
+
+func convertCtyValueToNode(v cty.Value) *CandidateNode {
+	if v.IsNull() {
+		return createScalarNode(nil, "")
+	}
+	switch {
+	case v.Type().Equals(cty.String):
+		return createScalarNode("", v.AsString())
+	case v.Type().Equals(cty.Bool):
+		b := v.True()
+		return createScalarNode(b, strconv.FormatBool(b))
+	case v.Type() == cty.Number:
+		bf := v.AsBigFloat()
+		if bf == nil {
+			return createStringScalarNode(v.GoString())
+		}
+		if intVal, acc := bf.Int(nil); acc == big.Exact {
+			s := intVal.String()
+			return createScalarNode(intVal.Int64(), s)
+		}
+		s := bf.Text('g', -1)
+		return createScalarNode(0.0, s)
+	case v.Type().IsTupleType() || v.Type().IsListType() || v.Type().IsSetType():
+		seq := &CandidateNode{Kind: SequenceNode}
+		it := v.ElementIterator()
+		for it.Next() {
+			_, val := it.Element()
+			seq.AddChild(convertCtyValueToNode(val))
+		}
+		return seq
+	case v.Type().IsMapType() || v.Type().IsObjectType():
+		m := &CandidateNode{Kind: MappingNode}
+		it := v.ElementIterator()
+		for it.Next() {
+			key, val := it.Element()
+			keyNode := createStringScalarNode(key.AsString())
+			valNode := convertCtyValueToNode(val)
+			m.AddKeyValueChild(keyNode, valNode)
+		}
+		return m
+	default:
+		return createStringScalarNode(v.GoString())
+	}
+}

pkg/yqlib/decoder_ini.go

@@ -16,7 +16,7 @@ type iniDecoder struct {
 
 func NewINIDecoder() Decoder {
 	return &iniDecoder{
-		finished: false, // Initialize the flag as false
+		finished: false, // Initialise the flag as false
 	}
 }
 

pkg/yqlib/decoder_test.go

@@ -68,7 +68,7 @@ func mustProcessFormatScenario(s formatScenario, decoder Decoder, encoder Encode
 
 	result, err := processFormatScenario(s, decoder, encoder)
 	if err != nil {
-		log.Error("Bad scenario %v: %w", s.description, err)
+		log.Errorf("Bad scenario %v: %v", s.description, err)
 		return fmt.Sprintf("Bad scenario %v: %v", s.description, err.Error())
 	}
 	return result

pkg/yqlib/decoder_toml.go

@@ -8,16 +8,19 @@ import (
 	"fmt"
 	"io"
 	"strconv"
+	"strings"
 	"time"
 
 	toml "github.com/pelletier/go-toml/v2/unstable"
 )
 
 type tomlDecoder struct {
-	parser   toml.Parser
-	finished bool
-	d        DataTreeNavigator
-	rootMap  *CandidateNode
+	parser           toml.Parser
+	finished         bool
+	d                DataTreeNavigator
+	rootMap          *CandidateNode
+	pendingComments  []string // Head comments collected from Comment nodes
+	firstContentSeen bool     // Track if we've processed the first non-comment node
 }
 
 func NewTomlDecoder() Decoder {
@@ -28,7 +31,7 @@ func NewTomlDecoder() Decoder {
 }
 
 func (dec *tomlDecoder) Init(reader io.Reader) error {
-	dec.parser = toml.Parser{}
+	dec.parser = toml.Parser{KeepComments: true}
 	buf := new(bytes.Buffer)
 	_, err := buf.ReadFrom(reader)
 	if err != nil {
@@ -39,9 +42,24 @@ func (dec *tomlDecoder) Init(reader io.Reader) error {
 		Kind: MappingNode,
 		Tag:  "!!map",
 	}
+	dec.pendingComments = make([]string, 0)
+	dec.firstContentSeen = false
+	dec.finished = false
 	return nil
 }
 
+func (dec *tomlDecoder) attachOrphanedCommentsToNode(tableNodeValue *CandidateNode) {
+	if len(dec.pendingComments) > 0 {
+		comments := strings.Join(dec.pendingComments, "\n")
+		if tableNodeValue.HeadComment == "" {
+			tableNodeValue.HeadComment = comments
+		} else {
+			tableNodeValue.HeadComment = tableNodeValue.HeadComment + "\n" + comments
+		}
+		dec.pendingComments = make([]string, 0)
+	}
+}
+
 func (dec *tomlDecoder) getFullPath(tomlNode *toml.Node) []interface{} {
 	path := make([]interface{}, 0)
 	for {
@@ -56,13 +74,24 @@ func (dec *tomlDecoder) getFullPath(tomlNode *toml.Node) []interface{} {
 func (dec *tomlDecoder) processKeyValueIntoMap(rootMap *CandidateNode, tomlNode *toml.Node) error {
 	value := tomlNode.Value()
 	path := dec.getFullPath(value.Next())
-	log.Debug("processKeyValueIntoMap: %v", path)
 
 	valueNode, err := dec.decodeNode(value)
 	if err != nil {
 		return err
 	}
 
+	// Attach pending head comments
+	if len(dec.pendingComments) > 0 {
+		valueNode.HeadComment = strings.Join(dec.pendingComments, "\n")
+		dec.pendingComments = make([]string, 0)
+	}
+
+	// Check for inline comment chained to the KeyValue node
+	nextNode := tomlNode.Next()
+	if nextNode != nil && nextNode.Kind == toml.Comment {
+		valueNode.LineComment = string(nextNode.Data)
+	}
+
 	context := Context{}
 	context = context.SingleChildContext(rootMap)
 
@@ -77,15 +106,19 @@ func (dec *tomlDecoder) decodeKeyValuesIntoMap(rootMap *CandidateNode, tomlNode
 
 	for dec.parser.NextExpression() {
 		nextItem := dec.parser.Expression()
-		log.Debug("decodeKeyValuesIntoMap -- next exp, its a %v", nextItem.Kind)
+		log.Debugf("decodeKeyValuesIntoMap -- next exp, its a %v", nextItem.Kind)
 
-		if nextItem.Kind == toml.KeyValue {
+		switch nextItem.Kind {
+		case toml.KeyValue:
 			if err := dec.processKeyValueIntoMap(rootMap, nextItem); err != nil {
 				return false, err
 			}
-		} else {
+		case toml.Comment:
+			// Standalone comment - add to pending for next element
+			dec.pendingComments = append(dec.pendingComments, string(nextItem.Data))
+		default:
 			// run out of key values
-			log.Debug("done in decodeKeyValuesIntoMap, gota a %v", nextItem.Kind)
+			log.Debugf("done in decodeKeyValuesIntoMap, gota a %v", nextItem.Kind)
 			return true, nil
 		}
 	}
@@ -117,21 +150,39 @@ func (dec *tomlDecoder) createInlineTableMap(tomlNode *toml.Node) (*CandidateNod
 	}
 
 	return &CandidateNode{
-		Kind:    MappingNode,
-		Tag:     "!!map",
-		Content: content,
+		Kind:       MappingNode,
+		Tag:        "!!map",
+		EncodeHint: EncodeHintInline,
+		Content:    content,
 	}, nil
 }
 
 func (dec *tomlDecoder) createArray(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := make([]*CandidateNode, 0)
+	var pendingArrayComments []string
+
 	iterator := tomlNode.Children()
 	for iterator.Next() {
 		child := iterator.Node()
+
+		// Handle comments within arrays
+		if child.Kind == toml.Comment {
+			// Collect comments to attach to the next array element
+			pendingArrayComments = append(pendingArrayComments, string(child.Data))
+			continue
+		}
+
 		yamlNode, err := dec.decodeNode(child)
 		if err != nil {
 			return nil, err
 		}
+
+		// Attach any pending comments to this array element
+		if len(pendingArrayComments) > 0 {
+			yamlNode.HeadComment = strings.Join(pendingArrayComments, "\n")
+			pendingArrayComments = make([]string, 0)
+		}
+
 		content = append(content, yamlNode)
 	}
 
@@ -221,7 +272,7 @@ func (dec *tomlDecoder) Decode() (*CandidateNode, error) {
 
 		currentNode := dec.parser.Expression()
 
-		log.Debug("currentNode: %v ", currentNode.Kind)
+		log.Debugf("currentNode: %v ", currentNode.Kind)
 		runAgainstCurrentExp, err = dec.processTopLevelNode(currentNode)
 		if err != nil {
 			return dec.rootMap, err
@@ -248,24 +299,43 @@ func (dec *tomlDecoder) Decode() (*CandidateNode, error) {
 func (dec *tomlDecoder) processTopLevelNode(currentNode *toml.Node) (bool, error) {
 	var runAgainstCurrentExp bool
 	var err error
-	log.Debug("processTopLevelNode: Going to process %v state is current %v", currentNode.Kind, NodeToString(dec.rootMap))
+	log.Debugf("processTopLevelNode: Going to process %v state is current %v", currentNode.Kind, NodeToString(dec.rootMap))
 	switch currentNode.Kind {
+	case toml.Comment:
+		// Collect comment to attach to next element
+		commentText := string(currentNode.Data)
+		// If we haven't seen any content yet, accumulate comments for root
+		if !dec.firstContentSeen {
+			if dec.rootMap.HeadComment == "" {
+				dec.rootMap.HeadComment = commentText
+			} else {
+				dec.rootMap.HeadComment = dec.rootMap.HeadComment + "\n" + commentText
+			}
+		} else {
+			// We've seen content, so these comments are for the next element
+			dec.pendingComments = append(dec.pendingComments, commentText)
+		}
+		return false, nil
 	case toml.Table:
+		dec.firstContentSeen = true
 		runAgainstCurrentExp, err = dec.processTable(currentNode)
 	case toml.ArrayTable:
+		dec.firstContentSeen = true
 		runAgainstCurrentExp, err = dec.processArrayTable(currentNode)
 	default:
+		dec.firstContentSeen = true
 		runAgainstCurrentExp, err = dec.decodeKeyValuesIntoMap(dec.rootMap, currentNode)
 	}
 
-	log.Debug("processTopLevelNode: DONE Processing state is now %v", NodeToString(dec.rootMap))
+	log.Debugf("processTopLevelNode: DONE Processing state is now %v", NodeToString(dec.rootMap))
 	return runAgainstCurrentExp, err
 }
 
 func (dec *tomlDecoder) processTable(currentNode *toml.Node) (bool, error) {
 	log.Debug("Enter processTable")
-	fullPath := dec.getFullPath(currentNode.Child())
-	log.Debug("fullpath: %v", fullPath)
+	child := currentNode.Child()
+	fullPath := dec.getFullPath(child)
+	log.Debugf("fullpath: %v", fullPath)
 
 	c := Context{}
 	c = c.SingleChildContext(dec.rootMap)
@@ -276,27 +346,53 @@ func (dec *tomlDecoder) processTable(currentNode *toml.Node) (bool, error) {
 	}
 
 	tableNodeValue := &CandidateNode{
-		Kind:    MappingNode,
-		Tag:     "!!map",
-		Content: make([]*CandidateNode, 0),
+		Kind:       MappingNode,
+		Tag:        "!!map",
+		Content:    make([]*CandidateNode, 0),
+		EncodeHint: EncodeHintSeparateBlock,
+	}
+
+	// Attach pending head comments to the table
+	if len(dec.pendingComments) > 0 {
+		tableNodeValue.HeadComment = strings.Join(dec.pendingComments, "\n")
+		dec.pendingComments = make([]string, 0)
 	}
 
 	var tableValue *toml.Node
 	runAgainstCurrentExp := false
-	hasValue := dec.parser.NextExpression()
-	// check to see if there is any table data
-	if hasValue {
+	sawKeyValue := false
+	for dec.parser.NextExpression() {
 		tableValue = dec.parser.Expression()
-		// next expression is not table data, so we are done
-		if tableValue.Kind != toml.KeyValue {
-			log.Debug("got an empty table")
-			runAgainstCurrentExp = true
-		} else {
-			runAgainstCurrentExp, err = dec.decodeKeyValuesIntoMap(tableNodeValue, tableValue)
-			if err != nil && !errors.Is(err, io.EOF) {
-				return false, err
-			}
+		// Allow standalone comments inside the table before the first key-value.
+		// These should be associated with the next element in the table (usually the first key-value),
+		// not treated as "end of table" (which would cause subsequent key-values to be parsed at root).
+		if tableValue.Kind == toml.Comment {
+			dec.pendingComments = append(dec.pendingComments, string(tableValue.Data))
+			continue
 		}
+
+		// next expression is not table data, so we are done (but we need to re-process it at top-level)
+		if tableValue.Kind != toml.KeyValue {
+			log.Debug("got an empty table (or reached next section)")
+			// If the table had only comments, attach them to the table itself so they don't leak to the next node.
+			if !sawKeyValue {
+				dec.attachOrphanedCommentsToNode(tableNodeValue)
+			}
+			runAgainstCurrentExp = true
+			break
+		}
+
+		sawKeyValue = true
+		runAgainstCurrentExp, err = dec.decodeKeyValuesIntoMap(tableNodeValue, tableValue)
+		if err != nil && !errors.Is(err, io.EOF) {
+			return false, err
+		}
+		break
+	}
+	// If we hit EOF after only seeing comments inside this table, attach them to the table itself
+	// so they don't leak to whatever comes next.
+	if !sawKeyValue {
+		dec.attachOrphanedCommentsToNode(tableNodeValue)
 	}
 
 	err = dec.d.DeeplyAssign(c, fullPath, tableNodeValue)
@@ -307,7 +403,7 @@ func (dec *tomlDecoder) processTable(currentNode *toml.Node) (bool, error) {
 }
 
 func (dec *tomlDecoder) arrayAppend(context Context, path []interface{}, rhsNode *CandidateNode) error {
-	log.Debug("arrayAppend to path: %v,%v", path, NodeToString(rhsNode))
+	log.Debugf("arrayAppend to path: %v,%v", path, NodeToString(rhsNode))
 	rhsCandidateNode := &CandidateNode{
 		Kind:    SequenceNode,
 		Tag:     "!!seq",
@@ -330,8 +426,9 @@ func (dec *tomlDecoder) arrayAppend(context Context, path []interface{}, rhsNode
 
 func (dec *tomlDecoder) processArrayTable(currentNode *toml.Node) (bool, error) {
 	log.Debug("Enter processArrayTable")
-	fullPath := dec.getFullPath(currentNode.Child())
-	log.Debug("Fullpath: %v", fullPath)
+	child := currentNode.Child()
+	fullPath := dec.getFullPath(child)
+	log.Debugf("Fullpath: %v", fullPath)
 
 	c := Context{}
 	c = c.SingleChildContext(dec.rootMap)
@@ -346,23 +443,64 @@ func (dec *tomlDecoder) processArrayTable(currentNode *toml.Node) (bool, error)
 	hasValue := dec.parser.NextExpression()
 
 	tableNodeValue := &CandidateNode{
-		Kind: MappingNode,
-		Tag:  "!!map",
+		Kind:       MappingNode,
+		Tag:        "!!map",
+		EncodeHint: EncodeHintSeparateBlock,
 	}
+
+	// Attach pending head comments to the array table
+	if len(dec.pendingComments) > 0 {
+		tableNodeValue.HeadComment = strings.Join(dec.pendingComments, "\n")
+		dec.pendingComments = make([]string, 0)
+	}
+
 	runAgainstCurrentExp := false
-	// if the next value is a ArrayTable or Table, then its not part of this declaration (not a key value pair)
-	// so lets leave that expression for the next round of parsing
-	if hasValue && (dec.parser.Expression().Kind == toml.ArrayTable || dec.parser.Expression().Kind == toml.Table) {
-		runAgainstCurrentExp = true
-	} else if hasValue {
-		// otherwise, if there is a value, it must be some key value pairs of the
-		// first object in the array!
-		tableValue := dec.parser.Expression()
-		runAgainstCurrentExp, err = dec.decodeKeyValuesIntoMap(tableNodeValue, tableValue)
-		if err != nil && !errors.Is(err, io.EOF) {
-			return false, err
+	sawKeyValue := false
+	if hasValue {
+		for {
+			exp := dec.parser.Expression()
+			// Allow standalone comments inside array tables before the first key-value.
+			if exp.Kind == toml.Comment {
+				dec.pendingComments = append(dec.pendingComments, string(exp.Data))
+				hasValue = dec.parser.NextExpression()
+				if !hasValue {
+					break
+				}
+				continue
+			}
+
+			// if the next value is a ArrayTable or Table, then its not part of this declaration (not a key value pair)
+			// so lets leave that expression for the next round of parsing
+			if exp.Kind == toml.ArrayTable || exp.Kind == toml.Table {
+				// If this array-table entry had only comments, attach them to the entry so they don't leak.
+				if !sawKeyValue {
+					dec.attachOrphanedCommentsToNode(tableNodeValue)
+				}
+				runAgainstCurrentExp = true
+				break
+			}
+
+			sawKeyValue = true
+			// otherwise, if there is a value, it must be some key value pairs of the
+			// first object in the array!
+			runAgainstCurrentExp, err = dec.decodeKeyValuesIntoMap(tableNodeValue, exp)
+			if err != nil && !errors.Is(err, io.EOF) {
+				return false, err
+			}
+			break
 		}
 	}
+	// If we hit EOF after only seeing comments inside this array-table entry, attach them to the entry
+	// so they don't leak to whatever comes next.
+	if !sawKeyValue && len(dec.pendingComments) > 0 {
+		comments := strings.Join(dec.pendingComments, "\n")
+		if tableNodeValue.HeadComment == "" {
+			tableNodeValue.HeadComment = comments
+		} else {
+			tableNodeValue.HeadComment = tableNodeValue.HeadComment + "\n" + comments
+		}
+		dec.pendingComments = make([]string, 0)
+	}
 
 	// += function
 	err = dec.arrayAppend(c, fullPath, tableNodeValue)
@@ -375,23 +513,42 @@ func (dec *tomlDecoder) processArrayTable(currentNode *toml.Node) (bool, error)
 // Because TOML. So we'll inject the last index into the path.
 
 func getPathToUse(fullPath []interface{}, dec *tomlDecoder, c Context) ([]interface{}, error) {
-	pathToCheck := fullPath
-	if len(fullPath) >= 1 {
-		pathToCheck = fullPath[:len(fullPath)-1]
-	}
-	readOp := createTraversalTree(pathToCheck, traversePreferences{DontAutoCreate: true}, false)
+	// We need to check the entire path (except the last element), not just the immediate parent,
+	// because we may have nested array tables like [[array.subarray.subsubarray]]
+	// where both 'array' and 'subarray' are arrays that already exist.
 
-	resultContext, err := dec.d.GetMatchingNodes(c, readOp)
-	if err != nil {
-		return nil, err
+	if len(fullPath) == 0 {
+		return fullPath, nil
 	}
-	if resultContext.MatchingNodes.Len() >= 1 {
-		match := resultContext.MatchingNodes.Front().Value.(*CandidateNode)
-		// path refers to an array, we need to add this to the last element in the array
-		if match.Kind == SequenceNode {
-			fullPath = append(pathToCheck, len(match.Content)-1, fullPath[len(fullPath)-1])
-			log.Debugf("Adding to end of %v array, using path: %v", pathToCheck, fullPath)
+
+	resultPath := make([]interface{}, 0, len(fullPath)*2) // preallocate with extra space for indices
+
+	// Process all segments except the last one
+	for i := 0; i < len(fullPath)-1; i++ {
+		resultPath = append(resultPath, fullPath[i])
+
+		// Check if the current path segment points to an array
+		readOp := createTraversalTree(resultPath, traversePreferences{DontAutoCreate: true}, false)
+		resultContext, err := dec.d.GetMatchingNodes(c, readOp)
+		if err != nil {
+			return nil, err
+		}
+
+		if resultContext.MatchingNodes.Len() >= 1 {
+			match := resultContext.MatchingNodes.Front().Value.(*CandidateNode)
+			// If this segment points to an array, we need to add the last index
+			// before continuing with the rest of the path
+			if match.Kind == SequenceNode && len(match.Content) > 0 {
+				lastIndex := len(match.Content) - 1
+				resultPath = append(resultPath, lastIndex)
+				log.Debugf("Path segment %v is an array, injecting index %d", resultPath[:len(resultPath)-1], lastIndex)
+			}
 		}
 	}
-	return fullPath, err
+
+	// Add the last segment
+	resultPath = append(resultPath, fullPath[len(fullPath)-1])
+
+	log.Debugf("getPathToUse: original path %v -> result path %v", fullPath, resultPath)
+	return resultPath, nil
 }

pkg/yqlib/decoder_uri_test.go

@@ -0,0 +1,160 @@
+//go:build !yq_nouri
+
+package yqlib
+
+import (
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+func TestUriDecoder_Init(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("test")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+}
+
+func TestUriDecoder_DecodeSimpleString(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("hello%20world")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "!!str", node.Tag)
+	test.AssertResult(t, "hello world", node.Value)
+}
+
+func TestUriDecoder_DecodeSpecialCharacters(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("hello%21%40%23%24%25")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "hello!@#$%", node.Value)
+}
+
+func TestUriDecoder_DecodeUTF8(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("%E2%9C%93%20check")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "✓ check", node.Value)
+}
+
+func TestUriDecoder_DecodePlusSign(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("a+b")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	// Note: url.QueryUnescape does NOT convert + to space
+	// That's only for form encoding (url.ParseQuery)
+	test.AssertResult(t, "a b", node.Value)
+}
+
+func TestUriDecoder_DecodeEmptyString(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "", node.Value)
+
+	// Second decode should return EOF
+	node, err = decoder.Decode()
+	test.AssertResult(t, io.EOF, err)
+	test.AssertResult(t, (*CandidateNode)(nil), node)
+}
+
+func TestUriDecoder_DecodeMultipleCalls(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("test")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	// First decode
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "test", node.Value)
+
+	// Second decode should return EOF since we've consumed all input
+	node, err = decoder.Decode()
+	test.AssertResult(t, io.EOF, err)
+	test.AssertResult(t, (*CandidateNode)(nil), node)
+}
+
+func TestUriDecoder_DecodeInvalidEscape(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("test%ZZ")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	_, err = decoder.Decode()
+	// Should return an error for invalid escape sequence
+	if err == nil {
+		t.Error("Expected error for invalid escape sequence, got nil")
+	}
+}
+
+func TestUriDecoder_DecodeSlashAndQuery(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("path%2Fto%2Ffile%3Fquery%3Dvalue")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "path/to/file?query=value", node.Value)
+}
+
+func TestUriDecoder_DecodePercent(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("100%25")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "100%", node.Value)
+}
+
+func TestUriDecoder_DecodeNoEscaping(t *testing.T) {
+	decoder := NewUriDecoder()
+	reader := strings.NewReader("simple_text-123")
+	err := decoder.Init(reader)
+	test.AssertResult(t, nil, err)
+
+	node, err := decoder.Decode()
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "simple_text-123", node.Value)
+}
+
+// Mock reader that returns an error
+type errorReader struct{}
+
+func (e *errorReader) Read(_ []byte) (n int, err error) {
+	return 0, io.ErrUnexpectedEOF
+}
+
+func TestUriDecoder_DecodeReadError(t *testing.T) {
+	decoder := NewUriDecoder()
+	err := decoder.Init(&errorReader{})
+	test.AssertResult(t, nil, err)
+
+	_, err = decoder.Decode()
+	test.AssertResult(t, io.ErrUnexpectedEOF, err)
+}

pkg/yqlib/decoder_xml.go

@@ -64,7 +64,7 @@ func (dec *xmlDecoder) processComment(c string) string {
 }
 
 func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
-	log.Debug("createMap: headC: %v, lineC: %v, footC: %v", n.HeadComment, n.LineComment, n.FootComment)
+	log.Debugf("createMap: headC: %v, lineC: %v, footC: %v", n.HeadComment, n.LineComment, n.FootComment)
 	yamlNode := &CandidateNode{Kind: MappingNode, Tag: "!!map"}
 
 	if len(n.Data) > 0 {
@@ -92,7 +92,7 @@ func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
 		log.Debugf("label=%v, i=%v, keyValuePair.FootComment: %v", label, i, keyValuePair.FootComment)
 		labelNode.FootComment = dec.processComment(keyValuePair.FootComment)
 
-		log.Debug("len of children in %v is %v", label, len(children))
+		log.Debugf("len of children in %v is %v", label, len(children))
 		if len(children) > 1 {
 			valueNode, err = dec.createSequence(children)
 			if err != nil {
@@ -105,7 +105,7 @@ func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
 			if len(children[0].Children) == 0 && children[0].HeadComment != "" {
 				if len(children[0].Data) > 0 {
 
-					log.Debug("scalar comment hack, currentlabel [%v]", labelNode.HeadComment)
+					log.Debugf("scalar comment hack, currentlabel [%v]", labelNode.HeadComment)
 					labelNode.HeadComment = joinComments([]string{labelNode.HeadComment, strings.TrimSpace(children[0].HeadComment)}, "\n")
 					children[0].HeadComment = ""
 				} else {
@@ -151,7 +151,7 @@ func (dec *xmlDecoder) convertToYamlNode(n *xmlNode) (*CandidateNode, error) {
 
 	scalar := dec.createValueNodeFromData(n.Data)
 
-	log.Debug("scalar (%v), headC: %v, lineC: %v, footC: %v", scalar.Tag, n.HeadComment, n.LineComment, n.FootComment)
+	log.Debugf("scalar (%v), headC: %v, lineC: %v, footC: %v", scalar.Tag, n.HeadComment, n.LineComment, n.FootComment)
 	scalar.HeadComment = dec.processComment(n.HeadComment)
 	scalar.LineComment = dec.processComment(n.LineComment)
 	if scalar.Tag == "!!seq" {
@@ -211,17 +211,17 @@ func (n *xmlNode) AddChild(s string, c *xmlNode) {
 	if n.Children == nil {
 		n.Children = make([]*xmlChildrenKv, 0)
 	}
-	log.Debug("looking for %s", s)
+	log.Debugf("looking for %s", s)
 	// see if we can find an existing entry to add to
 	for _, childEntry := range n.Children {
 		if childEntry.K == s {
-			log.Debug("found it, appending an entry%s", s)
+			log.Debugf("found it, appending an entry%s", s)
 			childEntry.V = append(childEntry.V, c)
-			log.Debug("yay len of children in %v is %v", s, len(childEntry.V))
+			log.Debugf("yay len of children in %v is %v", s, len(childEntry.V))
 			return
 		}
 	}
-	log.Debug("not there, making a new one %s", s)
+	log.Debugf("not there, making a new one %s", s)
 	n.Children = append(n.Children, &xmlChildrenKv{K: s, V: []*xmlNode{c}})
 }
 
@@ -267,7 +267,7 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 
 		switch se := t.(type) {
 		case xml.StartElement:
-			log.Debug("start element %v", se.Name.Local)
+			log.Debugf("start element %v", se.Name.Local)
 			elem.state = "started"
 			// Build new a new current element and link it to its parent
 			var label = se.Name.Local
@@ -302,14 +302,14 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 			if len(newBit) > 0 {
 				elem.n.Data = append(elem.n.Data, newBit)
 				elem.state = "chardata"
-				log.Debug("chardata [%v] for %v", elem.n.Data, elem.label)
+				log.Debugf("chardata [%v] for %v", elem.n.Data, elem.label)
 			}
 		case xml.EndElement:
 			if elem == nil {
 				log.Debug("no element, probably bad xml")
 				continue
 			}
-			log.Debug("end element %v", elem.label)
+			log.Debugf("end element %v", elem.label)
 			elem.state = "finished"
 			// And add it to its parent list
 			if elem.parent != nil {
@@ -326,10 +326,10 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 				applyFootComment(elem, commentStr)
 
 			case "chardata":
-				log.Debug("got a line comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
+				log.Debugf("got a line comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
 				elem.n.LineComment = joinComments([]string{elem.n.LineComment, commentStr}, " ")
 			default:
-				log.Debug("got a head comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
+				log.Debugf("got a head comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
 				elem.n.HeadComment = joinComments([]string{elem.n.HeadComment, commentStr}, " ")
 			}
 
@@ -354,7 +354,7 @@ func applyFootComment(elem *element, commentStr string) {
 	if len(elem.n.Children) > 0 {
 		lastChildIndex := len(elem.n.Children) - 1
 		childKv := elem.n.Children[lastChildIndex]
-		log.Debug("got a foot comment, putting on last child for %v: [%v]", childKv.K, commentStr)
+		log.Debugf("got a foot comment, putting on last child for %v: [%v]", childKv.K, commentStr)
 		// if it's an array of scalars, put the foot comment on the scalar itself
 		if len(childKv.V) > 0 && len(childKv.V[0].Children) == 0 {
 			nodeToUpdate := childKv.V[len(childKv.V)-1]
@@ -363,7 +363,7 @@ func applyFootComment(elem *element, commentStr string) {
 			childKv.FootComment = joinComments([]string{elem.n.FootComment, commentStr}, " ")
 		}
 	} else {
-		log.Debug("got a foot comment for %v: [%v]", elem.label, commentStr)
+		log.Debugf("got a foot comment for %v: [%v]", elem.label, commentStr)
 		elem.n.FootComment = joinComments([]string{elem.n.FootComment, commentStr}, " ")
 	}
 }

pkg/yqlib/decoder_yaml.go

@@ -78,7 +78,7 @@ func (dec *yamlDecoder) processReadStream(reader *bufio.Reader) (io.Reader, stri
 		if separatorPrefixRe.MatchString(line) {
 			match := separatorPrefixRe.FindString(line)
 			remainder := line[len(match):]
-			// normalize separator newline: if original had none, default to LF
+			// normalise separator newline: if original had none, default to LF
 			sepNewline := newline
 			if sepNewline == "" {
 				sepNewline = "\n"

pkg/yqlib/doc/operators/anchor-and-alias-operators.md

@@ -22,7 +22,7 @@ see https://yaml.org/type/merge.html
 
 Given a sample.yml file of:
 ```yaml
-- &CENTER
+- &CENTRE
   x: 1
   y: 2
 - &LEFT
@@ -32,7 +32,7 @@ Given a sample.yml file of:
   r: 10
 - &SMALL
   r: 1
-- !!merge <<: *CENTER
+- !!merge <<: *CENTRE
   r: 10
 ```
 then
@@ -288,7 +288,7 @@ see https://yaml.org/type/merge.html. This has the correct data, but the wrong k
 
 Given a sample.yml file of:
 ```yaml
-- &CENTER
+- &CENTRE
   x: 1
   y: 2
 - &LEFT
@@ -299,7 +299,7 @@ Given a sample.yml file of:
 - &SMALL
   r: 1
 - !!merge <<:
-    - *CENTER
+    - *CENTRE
     - *BIG
 ```
 then
@@ -318,7 +318,7 @@ see https://yaml.org/type/merge.html. This has the correct data, but the wrong k
 
 Given a sample.yml file of:
 ```yaml
-- &CENTER
+- &CENTRE
   x: 1
   y: 2
 - &LEFT
@@ -401,7 +401,7 @@ Taken from https://yaml.org/type/merge.html. Same values as legacy, but with the
 
 Given a sample.yml file of:
 ```yaml
-- &CENTER
+- &CENTRE
   x: 1
   y: 2
 - &LEFT
@@ -412,7 +412,7 @@ Given a sample.yml file of:
 - &SMALL
   r: 1
 - !!merge <<:
-    - *CENTER
+    - *CENTRE
     - *BIG
 ```
 then
@@ -432,7 +432,7 @@ Taken from https://yaml.org/type/merge.html. Same values as legacy, but with the
 
 Given a sample.yml file of:
 ```yaml
-- &CENTER
+- &CENTRE
   x: 1
   y: 2
 - &LEFT

pkg/yqlib/doc/operators/datetime.md

@@ -2,7 +2,7 @@
 
 Various operators for parsing and manipulating dates. 
 
-## Date time formattings
+## Date time formatting
 This uses Golang's built in time library for parsing and formatting date times.
 
 When not specified, the RFC3339 standard is assumed `2006-01-02T15:04:05Z07:00` for parsing.

pkg/yqlib/doc/operators/headers/datetime.md

@@ -2,7 +2,7 @@
 
 Various operators for parsing and manipulating dates. 
 
-## Date time formattings
+## Date time formatting
 This uses Golang's built in time library for parsing and formatting date times.
 
 When not specified, the RFC3339 standard is assumed `2006-01-02T15:04:05Z07:00` for parsing.

pkg/yqlib/doc/operators/headers/slice-array.md

@@ -1,5 +1,5 @@
-# Slice/Splice Array
+# Slice Array or String
 
-The slice array operator takes an array as input and returns a subarray. Like the `jq` equivalent, `.[10:15]` will return an array of length 5, starting from index 10 inclusive, up to index 15 exclusive. Negative numbers count backwards from the end of the array.
+The slice operator works on both arrays and strings. Like the `jq` equivalent, `.[10:15]` will return a subarray (or substring) of length 5, starting from index 10 inclusive, up to index 15 exclusive. Negative numbers count backwards from the end of the array or string.
 
-You may leave out the first or second number, which will refer to the start or end of the array respectively.
+You may leave out the first or second number, which will refer to the start or end of the array or string respectively.

pkg/yqlib/doc/operators/headers/system-operators.md

@@ -0,0 +1,27 @@
+# System Operators
+
+The `system` operator allows you to run an external command and use its output as a value in your expression.
+
+**Security warning**: The system operator is disabled by default. You must explicitly pass `--security-enable-system-operator` to use it.
+
+**Note:** When enabled, the system operator can replicate the functionality of `env` and `load`
+operators via external commands. Enabling it effectively overrides `--security-disable-env-ops`
+and `--security-disable-file-ops`.
+
+## Usage
+
+```bash
+yq --security-enable-system-operator --null-input '.field = system("command"; "arg1")'
+```
+
+The operator takes:
+- A command string (required)
+- An argument (or an array of arguments), separated from the command by `;` (optional)
+
+The current matched node's value is serialised and piped to the command via stdin. The command's stdout (with trailing newline stripped) is returned as a string.
+
+## Disabling the system operator
+
+The system operator is disabled by default. When disabled, an error is returned instead of running the command, consistent with `--security-disable-env-ops` and `--security-disable-file-ops`.
+
+Use `--security-enable-system-operator` flag to enable it.

pkg/yqlib/doc/operators/parent.md

@@ -79,6 +79,46 @@ will output
       c: cat
 ```
 
+## Get the top (root) parent
+Use negative numbers to get the top parents. You can think of this as indexing into the 'parents' array above
+
+Given a sample.yml file of:
+```yaml
+a:
+  b:
+    c: cat
+```
+then
+```bash
+yq '.a.b.c | parent(-1)' sample.yml
+```
+will output
+```yaml
+a:
+  b:
+    c: cat
+```
+
+## Root
+Alias for parent(-1), returns the top level parent. This is usually the document node.
+
+Given a sample.yml file of:
+```yaml
+a:
+  b:
+    c: cat
+```
+then
+```bash
+yq '.a.b.c | root' sample.yml
+```
+will output
+```yaml
+a:
+  b:
+    c: cat
+```
+
 ## N-th parent
 You can optionally supply the number of levels to go up for the parent, the default being 1.
 
@@ -116,6 +156,25 @@ a:
     c: cat
 ```
 
+## N-th negative
+Similarly, use negative numbers to index backwards from the parents array
+
+Given a sample.yml file of:
+```yaml
+a:
+  b:
+    c: cat
+```
+then
+```bash
+yq '.a.b.c | parent(-2)' sample.yml
+```
+will output
+```yaml
+b:
+  c: cat
+```
+
 ## No parent
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/operators/slice-array.md

@@ -1,8 +1,8 @@
-# Slice/Splice Array
+# Slice Array or String
 
-The slice array operator takes an array as input and returns a subarray. Like the `jq` equivalent, `.[10:15]` will return an array of length 5, starting from index 10 inclusive, up to index 15 exclusive. Negative numbers count backwards from the end of the array.
+The slice operator works on both arrays and strings. Like the `jq` equivalent, `.[10:15]` will return a subarray (or substring) of length 5, starting from index 10 inclusive, up to index 15 exclusive. Negative numbers count backwards from the end of the array or string.
 
-You may leave out the first or second number, which will refer to the start or end of the array respectively.
+You may leave out the first or second number, which will refer to the start or end of the array or string respectively.
 
 ## Slicing arrays
 Given a sample.yml file of:
@@ -103,3 +103,81 @@ will output
 - cow
 ```
 
+## Slicing strings
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq '.country[0:5]' sample.yml
+```
+will output
+```yaml
+Austr
+```
+
+## Slicing strings - without the second number
+Finishes at the end of the string
+
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq '.country[5:]' sample.yml
+```
+will output
+```yaml
+alia
+```
+
+## Slicing strings - without the first number
+Starts from the start of the string
+
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq '.country[:5]' sample.yml
+```
+will output
+```yaml
+Austr
+```
+
+## Slicing strings - use negative numbers to count backwards from the end
+Negative indices count from the end of the string
+
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq '.country[-5:]' sample.yml
+```
+will output
+```yaml
+ralia
+```
+
+## Slicing strings - Unicode
+Indices are rune-based, so multi-byte characters are handled correctly
+
+Given a sample.yml file of:
+```yaml
+greeting: héllo
+```
+then
+```bash
+yq '.greeting[1:3]' sample.yml
+```
+will output
+```yaml
+él
+```
+

pkg/yqlib/doc/operators/system-operators.md

@@ -0,0 +1,76 @@
+# System Operators
+
+The `system` operator allows you to run an external command and use its output as a value in your expression.
+
+**Security warning**: The system operator is disabled by default. You must explicitly pass `--security-enable-system-operator` to use it.
+
+**Note:** When enabled, the system operator can replicate the functionality of `env` and `load`
+operators via external commands. Enabling it effectively overrides `--security-disable-env-ops`
+and `--security-disable-file-ops`.
+
+## Usage
+
+```bash
+yq --security-enable-system-operator --null-input '.field = system("command"; "arg1")'
+```
+
+The operator takes:
+- A command string (required)
+- An argument (or an array of arguments), separated from the command by `;` (optional)
+
+The current matched node's value is serialised and piped to the command via stdin. The command's stdout (with trailing newline stripped) is returned as a string.
+
+## Disabling the system operator
+
+The system operator is disabled by default. When disabled, an error is returned instead of running the command, consistent with `--security-disable-env-ops` and `--security-disable-file-ops`.
+
+Use `--security-enable-system-operator` flag to enable it.
+
+## system operator returns error when disabled
+Use `--security-enable-system-operator` to enable the system operator.
+
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq '.country = system("/usr/bin/echo"; "test")' sample.yml
+```
+will output
+```bash
+Error: system operations are disabled, use --security-enable-system-operator to enable
+```
+
+## Run a command with an argument
+Use `--security-enable-system-operator` to enable the system operator.
+
+Given a sample.yml file of:
+```yaml
+country: Australia
+```
+then
+```bash
+yq --security-enable-system-operator '.country = system("/usr/bin/echo"; "test")' sample.yml
+```
+will output
+```yaml
+country: test
+```
+
+## Run a command without arguments
+Omit the semicolon and args to run the command with no extra arguments.
+
+Given a sample.yml file of:
+```yaml
+a: hello
+```
+then
+```bash
+yq --security-enable-system-operator '.a = system("/usr/bin/echo")' sample.yml
+```
+will output
+```yaml
+a: ""
+```
+

pkg/yqlib/doc/usage/hcl.md

@@ -0,0 +1,201 @@
+# HCL
+
+Encode and decode to and from [HashiCorp Configuration Language (HCL)](https://github.com/hashicorp/hcl).
+
+HCL is commonly used in HashiCorp tools like Terraform for configuration files. The yq HCL encoder and decoder support:
+- Blocks and attributes
+- String interpolation and expressions (preserved without quotes)
+- Comments (leading, head, and line comments)
+- Nested structures (maps and lists)
+- Syntax colorisation when enabled
+
+
+## Parse HCL
+Given a sample.hcl file of:
+```hcl
+io_mode = "async"
+```
+then
+```bash
+yq -oy sample.hcl
+```
+will output
+```yaml
+io_mode: "async"
+```
+
+## Roundtrip: Sample Doc
+Given a sample.hcl file of:
+```hcl
+service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+
+```
+then
+```bash
+yq sample.hcl
+```
+will output
+```hcl
+service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+```
+
+## Roundtrip: With an update
+Given a sample.hcl file of:
+```hcl
+service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+
+```
+then
+```bash
+yq '.service.cat.process.main.command += "meow"' sample.hcl
+```
+will output
+```hcl
+service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server", "meow"]
+  }
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+```
+
+## Parse HCL: Sample Doc
+Given a sample.hcl file of:
+```hcl
+service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+
+```
+then
+```bash
+yq -oy sample.hcl
+```
+will output
+```yaml
+service:
+  cat:
+    process:
+      main:
+        command:
+          - "/usr/local/bin/awesome-app"
+          - "server"
+      management:
+        command:
+          - "/usr/local/bin/awesome-app"
+          - "management"
+```
+
+## Parse HCL: with comments
+Given a sample.hcl file of:
+```hcl
+# Configuration
+port = 8080 # server port
+```
+then
+```bash
+yq -oy sample.hcl
+```
+will output
+```yaml
+# Configuration
+port: 8080 # server port
+```
+
+## Roundtrip: with comments
+Given a sample.hcl file of:
+```hcl
+# Configuration
+port = 8080
+```
+then
+```bash
+yq sample.hcl
+```
+will output
+```hcl
+# Configuration
+port = 8080
+```
+
+## Roundtrip: With templates, functions and arithmetic
+Given a sample.hcl file of:
+```hcl
+# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+
+# String interpolation and templates
+message = "Hello, ${name}!"
+
+# Application-provided functions
+shouty_message = upper(message)
+```
+then
+```bash
+yq sample.hcl
+```
+will output
+```hcl
+# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+# String interpolation and templates
+message = "Hello, ${name}!"
+# Application-provided functions
+shouty_message = upper(message)
+```
+
+## Roundtrip: Separate blocks with same name.
+Given a sample.hcl file of:
+```hcl
+resource "aws_instance" "web" {
+  ami = "ami-12345"
+}
+resource "aws_instance" "db" {
+  ami = "ami-67890"
+}
+```
+then
+```bash
+yq sample.hcl
+```
+will output
+```hcl
+resource "aws_instance" "web" {
+  ami = "ami-12345"
+}
+resource "aws_instance" "db" {
+  ami = "ami-67890"
+}
+```
+

pkg/yqlib/doc/usage/headers/hcl.md

@@ -0,0 +1,11 @@
+# HCL
+
+Encode and decode to and from [HashiCorp Configuration Language (HCL)](https://github.com/hashicorp/hcl).
+
+HCL is commonly used in HashiCorp tools like Terraform for configuration files. The yq HCL encoder and decoder support:
+- Blocks and attributes
+- String interpolation and expressions (preserved without quotes)
+- Comments (leading, head, and line comments)
+- Nested structures (maps and lists)
+- Syntax colorisation when enabled
+

pkg/yqlib/doc/usage/headers/kyaml.md

@@ -0,0 +1,9 @@
+# KYaml
+
+Encode and decode to and from KYaml (a restricted subset of YAML that uses flow-style collections).
+
+KYaml is useful when you want YAML data rendered in a compact, JSON-like form while still supporting YAML features like comments.
+
+Notes:
+- Strings are always double-quoted in KYaml output.
+- Anchors and aliases are expanded (KYaml output does not emit them).

pkg/yqlib/doc/usage/kyaml.md

@@ -0,0 +1,253 @@
+# KYaml
+
+Encode and decode to and from KYaml (a restricted subset of YAML that uses flow-style collections).
+
+KYaml is useful when you want YAML data rendered in a compact, JSON-like form while still supporting YAML features like comments.
+
+Notes:
+- Strings are always double-quoted in KYaml output.
+- Anchors and aliases are expanded (KYaml output does not emit them).
+
+## Encode kyaml: plain string scalar
+Strings are always double-quoted in KYaml output.
+
+Given a sample.yml file of:
+```yaml
+cat
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+"cat"
+```
+
+## encode flow mapping and sequence
+Given a sample.yml file of:
+```yaml
+a: b
+c:
+  - d
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  a: "b",
+  c: [
+    "d",
+  ],
+}
+```
+
+## encode non-string scalars
+Given a sample.yml file of:
+```yaml
+a: 12
+b: true
+c: null
+d: "true"
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  a: 12,
+  b: true,
+  c: null,
+  d: "true",
+}
+```
+
+## quote non-identifier keys
+Given a sample.yml file of:
+```yaml
+"1a": b
+"has space": c
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  "1a": "b",
+  "has space": "c",
+}
+```
+
+## escape quoted strings
+Given a sample.yml file of:
+```yaml
+a: "line1\nline2\t\"q\""
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  a: "line1\nline2\t\"q\"",
+}
+```
+
+## preserve comments when encoding
+Given a sample.yml file of:
+```yaml
+# leading
+a: 1 # a line
+# head b
+b: 2
+c:
+  # head d
+  - d # d line
+  - e
+# trailing
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+# leading
+{
+  a: 1, # a line
+  # head b
+  b: 2,
+  c: [
+    # head d
+    "d", # d line
+    "e",
+  ],
+  # trailing
+}
+```
+
+## Encode kyaml: anchors and aliases
+KYaml output does not support anchors/aliases; they are expanded to concrete values.
+
+Given a sample.yml file of:
+```yaml
+base: &base
+  a: b
+copy: *base
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  base: {
+    a: "b",
+  },
+  copy: {
+    a: "b",
+  },
+}
+```
+
+## Encode kyaml: yaml to kyaml shows formatting differences
+KYaml uses flow-style collections (braces/brackets) and explicit commas.
+
+Given a sample.yml file of:
+```yaml
+person:
+  name: John
+  pets:
+    - cat
+    - dog
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+{
+  person: {
+    name: "John",
+    pets: [
+      "cat",
+      "dog",
+    ],
+  },
+}
+```
+
+## Encode kyaml: nested lists of objects
+Lists and objects can be nested arbitrarily; KYaml always uses flow-style collections.
+
+Given a sample.yml file of:
+```yaml
+- name: a
+  items:
+    - id: 1
+      tags:
+        - k: x
+          v: y
+        - k: x2
+          v: y2
+    - id: 2
+      tags:
+        - k: z
+          v: w
+
+```
+then
+```bash
+yq -o=kyaml '.' sample.yml
+```
+will output
+```yaml
+[
+  {
+    name: "a",
+    items: [
+      {
+        id: 1,
+        tags: [
+          {
+            k: "x",
+            v: "y",
+          },
+          {
+            k: "x2",
+            v: "y2",
+          },
+        ],
+      },
+      {
+        id: 2,
+        tags: [
+          {
+            k: "z",
+            v: "w",
+          },
+        ],
+      },
+    ],
+  },
+]
+```
+

pkg/yqlib/doc/usage/toml.md

@@ -141,3 +141,263 @@ will output
 dependencies: {}
 ```
 
+## Roundtrip: inline table attribute
+Given a sample.toml file of:
+```toml
+name = { first = "Tom", last = "Preston-Werner" }
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+name = { first = "Tom", last = "Preston-Werner" }
+```
+
+## Roundtrip: table section
+Given a sample.toml file of:
+```toml
+[owner.contact]
+name = "Tom"
+age = 36
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+[owner.contact]
+name = "Tom"
+age = 36
+```
+
+## Roundtrip: array of tables
+Given a sample.toml file of:
+```toml
+[[fruits]]
+name = "apple"
+[[fruits.varieties]]
+name = "red delicious"
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+[[fruits]]
+name = "apple"
+[[fruits.varieties]]
+name = "red delicious"
+```
+
+## Roundtrip: arrays and scalars
+Given a sample.toml file of:
+```toml
+A = ["hello", ["world", "again"]]
+B = 12
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+A = ["hello", ["world", "again"]]
+B = 12
+```
+
+## Roundtrip: simple
+Given a sample.toml file of:
+```toml
+A = "hello"
+B = 12
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+A = "hello"
+B = 12
+```
+
+## Roundtrip: deep paths
+Given a sample.toml file of:
+```toml
+[person]
+name = "hello"
+address = "12 cat st"
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+[person]
+name = "hello"
+address = "12 cat st"
+```
+
+## Roundtrip: empty array
+Given a sample.toml file of:
+```toml
+A = []
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+A = []
+```
+
+## Roundtrip: sample table
+Given a sample.toml file of:
+```toml
+var = "x"
+
+[owner.contact]
+name = "Tom Preston-Werner"
+age = 36
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+var = "x"
+
+[owner.contact]
+name = "Tom Preston-Werner"
+age = 36
+```
+
+## Roundtrip: empty table
+Given a sample.toml file of:
+```toml
+[dependencies]
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+[dependencies]
+```
+
+## Roundtrip: comments
+Given a sample.toml file of:
+```toml
+# This is a comment
+A = "hello"  # inline comment
+B = 12
+
+# Table comment
+[person]
+name = "Tom"  # name comment
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+# This is a comment
+A = "hello"  # inline comment
+B = 12
+
+# Table comment
+[person]
+name = "Tom"  # name comment
+```
+
+## Roundtrip: sample from web
+Given a sample.toml file of:
+```toml
+# This is a TOML document
+title = "TOML Example"
+
+[owner]
+name = "Tom Preston-Werner"
+dob = 1979-05-27T07:32:00-08:00
+
+[database]
+enabled = true
+ports = [8000, 8001, 8002]
+data = [["delta", "phi"], [3.14]]
+temp_targets = { cpu = 79.5, case = 72.0 }
+
+# [servers] yq can't do this one yet
+[servers.alpha]
+ip = "10.0.0.1"
+role = "frontend"
+
+[servers.beta]
+ip = "10.0.0.2"
+role = "backend"
+
+```
+then
+```bash
+yq '.' sample.toml
+```
+will output
+```yaml
+# This is a TOML document
+title = "TOML Example"
+
+[owner]
+name = "Tom Preston-Werner"
+dob = 1979-05-27T07:32:00-08:00
+
+[database]
+enabled = true
+ports = [8000, 8001, 8002]
+data = [["delta", "phi"], [3.14]]
+temp_targets = { cpu = 79.5, case = 72.0 }
+
+# [servers] yq can't do this one yet
+[servers.alpha]
+ip = "10.0.0.1"
+role = "frontend"
+
+[servers.beta]
+ip = "10.0.0.2"
+role = "backend"
+```
+
+## Encode: Simple mapping produces table section
+Given a sample.yml file of:
+```yaml
+arg:
+  hello: foo
+
+```
+then
+```bash
+yq -o toml '.' sample.yml
+```
+will output
+```toml
+[arg]
+hello = "foo"
+```
+

pkg/yqlib/doc/usage/xml.md

@@ -53,7 +53,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -100,7 +100,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -157,7 +157,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -177,7 +177,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -196,7 +196,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -225,7 +225,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq '.' sample.xml
+yq sample.xml
 ```
 will output
 ```xml
@@ -256,7 +256,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq --xml-skip-directives '.' sample.xml
+yq --xml-skip-directives sample.xml
 ```
 will output
 ```xml
@@ -292,7 +292,7 @@ for x --></x>
 ```
 then
 ```bash
-yq -oy '.' sample.xml
+yq -oy sample.xml
 ```
 will output
 ```yaml
@@ -327,7 +327,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq --xml-keep-namespace=false '.' sample.xml
+yq --xml-keep-namespace=false sample.xml
 ```
 will output
 ```xml
@@ -361,7 +361,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq --xml-raw-token=false '.' sample.xml
+yq --xml-raw-token=false sample.xml
 ```
 will output
 ```xml
@@ -542,7 +542,7 @@ for x --></x>
 ```
 then
 ```bash
-yq '.' sample.xml
+yq sample.xml
 ```
 will output
 ```xml
@@ -575,7 +575,7 @@ Given a sample.xml file of:
 ```
 then
 ```bash
-yq '.' sample.xml
+yq sample.xml
 ```
 will output
 ```xml

pkg/yqlib/encoder.go

@@ -1,7 +1,12 @@
 package yqlib
 
 import (
+	"bufio"
+	"errors"
 	"io"
+	"strings"
+
+	"github.com/fatih/color"
 )
 
 type Encoder interface {
@@ -25,3 +30,63 @@ func mapKeysToStrings(node *CandidateNode) {
 		mapKeysToStrings(child)
 	}
 }
+
+// Some funcs are shared between encoder_yaml and encoder_kyaml
+func PrintYAMLDocumentSeparator(writer io.Writer, PrintDocSeparators bool) error {
+	if PrintDocSeparators {
+		log.Debug("writing doc sep")
+		if err := writeString(writer, "---\n"); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+func PrintYAMLLeadingContent(writer io.Writer, content string, PrintDocSeparators bool, ColorsEnabled bool) error {
+	reader := bufio.NewReader(strings.NewReader(content))
+
+	// reuse precompiled package-level regex
+	// (declared in decoder_yaml.go)
+
+	for {
+
+		readline, errReading := reader.ReadString('\n')
+		if errReading != nil && !errors.Is(errReading, io.EOF) {
+			return errReading
+		}
+		if strings.Contains(readline, "$yqDocSeparator$") {
+			// Preserve the original line ending (CRLF or LF)
+			lineEnding := "\n"
+			if strings.HasSuffix(readline, "\r\n") {
+				lineEnding = "\r\n"
+			}
+			if PrintDocSeparators {
+				if err := writeString(writer, "---"+lineEnding); err != nil {
+					return err
+				}
+			}
+
+		} else {
+			if len(readline) > 0 && readline != "\n" && readline[0] != '%' && !commentLineRe.MatchString(readline) {
+				readline = "# " + readline
+			}
+			if ColorsEnabled && strings.TrimSpace(readline) != "" {
+				readline = format(color.FgHiBlack) + readline + format(color.Reset)
+			}
+			if err := writeString(writer, readline); err != nil {
+				return err
+			}
+		}
+
+		if errors.Is(errReading, io.EOF) {
+			if readline != "" {
+				// the last comment we read didn't have a newline, put one in
+				if err := writeString(writer, "\n"); err != nil {
+					return err
+				}
+			}
+			break
+		}
+	}
+
+	return nil
+}

pkg/yqlib/encoder_hcl.go

@@ -0,0 +1,690 @@
+//go:build !yq_nohcl
+
+package yqlib
+
+import (
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+
+	"github.com/fatih/color"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+	hclwrite "github.com/hashicorp/hcl/v2/hclwrite"
+	"github.com/zclconf/go-cty/cty"
+)
+
+type hclEncoder struct {
+	prefs HclPreferences
+}
+
+// commentPathSep is used to join path segments when collecting comments.
+// It uses a rarely used ASCII control character to avoid collisions with
+// normal key names (including dots).
+const commentPathSep = "\x1e"
+
+// NewHclEncoder creates a new HCL encoder
+func NewHclEncoder(prefs HclPreferences) Encoder {
+	return &hclEncoder{prefs: prefs}
+}
+
+func (he *hclEncoder) CanHandleAliases() bool {
+	return false
+}
+
+func (he *hclEncoder) PrintDocumentSeparator(_ io.Writer) error {
+	return nil
+}
+
+func (he *hclEncoder) PrintLeadingContent(_ io.Writer, _ string) error {
+	return nil
+}
+
+func (he *hclEncoder) Encode(writer io.Writer, node *CandidateNode) error {
+	log.Debugf("I need to encode %v", NodeToString(node))
+	if node.Kind == ScalarNode {
+		return writeString(writer, node.Value+"\n")
+	}
+
+	f := hclwrite.NewEmptyFile()
+	body := f.Body()
+
+	// Collect comments as we encode
+	commentMap := make(map[string]string)
+	he.collectComments(node, "", commentMap)
+
+	if err := he.encodeNode(body, node); err != nil {
+		return fmt.Errorf("failed to encode HCL: %w", err)
+	}
+
+	// Get the formatted output and remove extra spacing before '='
+	output := f.Bytes()
+	compactOutput := he.compactSpacing(output)
+
+	// Inject comments back into the output
+	finalOutput := he.injectComments(compactOutput, commentMap)
+
+	if he.prefs.ColorsEnabled {
+		colourized := he.colorizeHcl(finalOutput)
+		_, err := writer.Write(colourized)
+		return err
+	}
+
+	_, err := writer.Write(finalOutput)
+	return err
+}
+
+// compactSpacing removes extra whitespace before '=' in attribute assignments
+func (he *hclEncoder) compactSpacing(input []byte) []byte {
+	// Use regex to replace multiple spaces before = with single space
+	re := regexp.MustCompile(`(\S)\s{2,}=`)
+	return re.ReplaceAll(input, []byte("$1 ="))
+}
+
+// collectComments recursively collects comments from nodes for later injection
+func (he *hclEncoder) collectComments(node *CandidateNode, prefix string, commentMap map[string]string) {
+	if node == nil {
+		return
+	}
+
+	// For mapping nodes, collect comments from keys and values
+	if node.Kind == MappingNode {
+		// Collect root-level head comment if at root (prefix is empty)
+		if prefix == "" && node.HeadComment != "" {
+			commentMap[joinCommentPath("__root__", "head")] = node.HeadComment
+		}
+
+		for i := 0; i < len(node.Content); i += 2 {
+			keyNode := node.Content[i]
+			valueNode := node.Content[i+1]
+			key := keyNode.Value
+
+			// Create a path for this key
+			path := joinCommentPath(prefix, key)
+
+			// Store comments from the key (head comments appear before the attribute)
+			if keyNode.HeadComment != "" {
+				commentMap[joinCommentPath(path, "head")] = keyNode.HeadComment
+			}
+			// Store comments from the value (line comments appear after the value)
+			if valueNode.LineComment != "" {
+				commentMap[joinCommentPath(path, "line")] = valueNode.LineComment
+			}
+			if valueNode.FootComment != "" {
+				commentMap[joinCommentPath(path, "foot")] = valueNode.FootComment
+			}
+
+			// Recurse into nested mappings
+			if valueNode.Kind == MappingNode {
+				he.collectComments(valueNode, path, commentMap)
+			}
+		}
+	}
+}
+
+// joinCommentPath concatenates path segments using commentPathSep, safely handling empty prefixes.
+func joinCommentPath(prefix, segment string) string {
+	if prefix == "" {
+		return segment
+	}
+	return prefix + commentPathSep + segment
+}
+
+// injectComments adds collected comments back into the HCL output
+func (he *hclEncoder) injectComments(output []byte, commentMap map[string]string) []byte {
+	// Convert output to string for easier manipulation
+	result := string(output)
+
+	// Root-level head comment (stored on the synthetic __root__/head path)
+	for path, comment := range commentMap {
+		if path == joinCommentPath("__root__", "head") {
+			trimmed := strings.TrimSpace(comment)
+			if trimmed != "" && !strings.HasPrefix(result, trimmed) {
+				result = trimmed + "\n" + result
+			}
+		}
+	}
+
+	// Attribute head comments: insert above matching assignment
+	for path, comment := range commentMap {
+		parts := strings.Split(path, commentPathSep)
+		if len(parts) < 2 {
+			continue
+		}
+
+		commentType := parts[len(parts)-1]
+		key := parts[len(parts)-2]
+		if commentType != "head" || key == "" {
+			continue
+		}
+
+		trimmed := strings.TrimSpace(comment)
+		if trimmed == "" {
+			continue
+		}
+
+		re := regexp.MustCompile(`(?m)^(\s*)` + regexp.QuoteMeta(key) + `\s*=`)
+		if re.MatchString(result) {
+			result = re.ReplaceAllString(result, "$1"+trimmed+"\n$0")
+		}
+	}
+
+	return []byte(result)
+}
+
+func (he *hclEncoder) colorizeHcl(input []byte) []byte {
+	hcl := string(input)
+	result := strings.Builder{}
+
+	// Create colour functions for different token types
+	commentColor := color.New(color.FgHiBlack).SprintFunc()
+	stringColor := color.New(color.FgGreen).SprintFunc()
+	numberColor := color.New(color.FgHiMagenta).SprintFunc()
+	keyColor := color.New(color.FgCyan).SprintFunc()
+	boolColor := color.New(color.FgHiMagenta).SprintFunc()
+
+	// Simple tokenization for HCL colouring
+	i := 0
+	for i < len(hcl) {
+		ch := hcl[i]
+
+		// Comments - from # to end of line
+		if ch == '#' {
+			end := i
+			for end < len(hcl) && hcl[end] != '\n' {
+				end++
+			}
+			result.WriteString(commentColor(hcl[i:end]))
+			i = end
+			continue
+		}
+
+		// Strings - quoted text
+		if ch == '"' || ch == '\'' {
+			quote := ch
+			end := i + 1
+			for end < len(hcl) && hcl[end] != quote {
+				if hcl[end] == '\\' {
+					end++ // skip escaped char
+				}
+				end++
+			}
+			if end < len(hcl) {
+				end++ // include closing quote
+			}
+			result.WriteString(stringColor(hcl[i:end]))
+			i = end
+			continue
+		}
+
+		// Numbers - sequences of digits, possibly with decimal point or minus
+		if (ch >= '0' && ch <= '9') || (ch == '-' && i+1 < len(hcl) && hcl[i+1] >= '0' && hcl[i+1] <= '9') {
+			end := i
+			if ch == '-' {
+				end++
+			}
+			for end < len(hcl) && ((hcl[end] >= '0' && hcl[end] <= '9') || hcl[end] == '.') {
+				end++
+			}
+			result.WriteString(numberColor(hcl[i:end]))
+			i = end
+			continue
+		}
+
+		// Identifiers/keys - alphanumeric + underscore
+		if (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || ch == '_' {
+			end := i
+			for end < len(hcl) && ((hcl[end] >= 'a' && hcl[end] <= 'z') ||
+				(hcl[end] >= 'A' && hcl[end] <= 'Z') ||
+				(hcl[end] >= '0' && hcl[end] <= '9') ||
+				hcl[end] == '_' || hcl[end] == '-') {
+				end++
+			}
+			ident := hcl[i:end]
+
+			// Check if this is a keyword/reserved word
+			switch ident {
+			case "true", "false", "null":
+				result.WriteString(boolColor(ident))
+			default:
+				// Check if followed by = (it's a key)
+				j := end
+				for j < len(hcl) && (hcl[j] == ' ' || hcl[j] == '\t') {
+					j++
+				}
+				if j < len(hcl) && hcl[j] == '=' {
+					result.WriteString(keyColor(ident))
+				} else if j < len(hcl) && hcl[j] == '{' {
+					// Block type
+					result.WriteString(keyColor(ident))
+				} else {
+					result.WriteString(ident) // plain text for other identifiers
+				}
+			}
+			i = end
+			continue
+		}
+
+		// Everything else (whitespace, operators, brackets) - no color
+		result.WriteByte(ch)
+		i++
+	}
+
+	return []byte(result.String())
+}
+
+// Helper runes for unquoted identifiers
+func isHCLIdentifierStart(r rune) bool {
+	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || r == '_'
+}
+
+func isHCLIdentifierPart(r rune) bool {
+	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '_' || r == '-'
+}
+
+func isValidHCLIdentifier(s string) bool {
+	if s == "" {
+		return false
+	}
+	// HCL identifiers must start with a letter or underscore
+	// and contain only letters, digits, underscores, and hyphens
+	for i, r := range s {
+		if i == 0 {
+			if !isHCLIdentifierStart(r) {
+				return false
+			}
+			continue
+		}
+		if !isHCLIdentifierPart(r) {
+			return false
+		}
+	}
+	return true
+}
+
+// tokensForRawHCLExpr produces a minimal token stream for a simple HCL expression so we can
+// write it without introducing quotes (e.g. function calls like upper(message)).
+func tokensForRawHCLExpr(expr string) (hclwrite.Tokens, error) {
+	var tokens hclwrite.Tokens
+	for i := 0; i < len(expr); {
+		ch := expr[i]
+		switch {
+		case ch == ' ' || ch == '\t':
+			i++
+			continue
+		case isHCLIdentifierStart(rune(ch)):
+			start := i
+			i++
+			for i < len(expr) && isHCLIdentifierPart(rune(expr[i])) {
+				i++
+			}
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenIdent, Bytes: []byte(expr[start:i])})
+			continue
+		case ch >= '0' && ch <= '9':
+			start := i
+			i++
+			for i < len(expr) && ((expr[i] >= '0' && expr[i] <= '9') || expr[i] == '.') {
+				i++
+			}
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenNumberLit, Bytes: []byte(expr[start:i])})
+			continue
+		case ch == '(':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenOParen, Bytes: []byte{'('}})
+		case ch == ')':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenCParen, Bytes: []byte{')'}})
+		case ch == ',':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenComma, Bytes: []byte{','}})
+		case ch == '.':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenDot, Bytes: []byte{'.'}})
+		case ch == '+':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenPlus, Bytes: []byte{'+'}})
+		case ch == '-':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenMinus, Bytes: []byte{'-'}})
+		case ch == '*':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenStar, Bytes: []byte{'*'}})
+		case ch == '/':
+			tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenSlash, Bytes: []byte{'/'}})
+		default:
+			return nil, fmt.Errorf("unsupported character %q in raw HCL expression", ch)
+		}
+		i++
+	}
+	return tokens, nil
+}
+
+// encodeAttribute encodes a value as an HCL attribute
+func (he *hclEncoder) encodeAttribute(body *hclwrite.Body, key string, valueNode *CandidateNode) error {
+	if valueNode.Kind == ScalarNode && valueNode.Tag == "!!str" {
+		// Handle unquoted expressions (as-is, without quotes)
+		if valueNode.Style == 0 {
+			tokens, err := tokensForRawHCLExpr(valueNode.Value)
+			if err != nil {
+				return err
+			}
+			body.SetAttributeRaw(key, tokens)
+			return nil
+		}
+		if valueNode.Style&LiteralStyle != 0 {
+			tokens, err := tokensForRawHCLExpr(valueNode.Value)
+			if err != nil {
+				return err
+			}
+			body.SetAttributeRaw(key, tokens)
+			return nil
+		}
+		// Check if template with interpolation
+		if valueNode.Style&DoubleQuotedStyle != 0 && strings.Contains(valueNode.Value, "${") {
+			return he.encodeTemplateAttribute(body, key, valueNode.Value)
+		}
+		// Check if unquoted identifier
+		if isValidHCLIdentifier(valueNode.Value) && valueNode.Style == 0 {
+			traversal := hcl.Traversal{
+				hcl.TraverseRoot{Name: valueNode.Value},
+			}
+			body.SetAttributeTraversal(key, traversal)
+			return nil
+		}
+	}
+	// Default: use cty.Value for quoted strings and all other types
+	ctyValue, err := nodeToCtyValue(valueNode)
+	if err != nil {
+		return err
+	}
+	body.SetAttributeValue(key, ctyValue)
+	return nil
+}
+
+// encodeTemplateAttribute encodes a template string with ${} interpolations
+func (he *hclEncoder) encodeTemplateAttribute(body *hclwrite.Body, key string, templateStr string) error {
+	tokens := hclwrite.Tokens{
+		{Type: hclsyntax.TokenOQuote, Bytes: []byte{'"'}},
+	}
+
+	for i := 0; i < len(templateStr); i++ {
+		if i < len(templateStr)-1 && templateStr[i] == '$' && templateStr[i+1] == '{' {
+			// Start of template interpolation
+			tokens = append(tokens, &hclwrite.Token{
+				Type:  hclsyntax.TokenTemplateInterp,
+				Bytes: []byte("${"),
+			})
+			i++ // skip the '{'
+			// Find the matching '}'
+			start := i + 1
+			depth := 1
+			for i++; i < len(templateStr) && depth > 0; i++ {
+				switch templateStr[i] {
+				case '{':
+					depth++
+				case '}':
+					depth--
+				}
+			}
+			i-- // back up to the '}'
+			interpExpr := templateStr[start:i]
+			tokens = append(tokens, &hclwrite.Token{
+				Type:  hclsyntax.TokenIdent,
+				Bytes: []byte(interpExpr),
+			})
+			tokens = append(tokens, &hclwrite.Token{
+				Type:  hclsyntax.TokenTemplateSeqEnd,
+				Bytes: []byte("}"),
+			})
+		} else {
+			// Regular character
+			tokens = append(tokens, &hclwrite.Token{
+				Type:  hclsyntax.TokenQuotedLit,
+				Bytes: []byte{templateStr[i]},
+			})
+		}
+	}
+	tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenCQuote, Bytes: []byte{'"'}})
+	body.SetAttributeRaw(key, tokens)
+	return nil
+}
+
+// encodeBlockIfMapping attempts to encode a value as a block. Returns true if it was encoded as a block.
+func (he *hclEncoder) encodeBlockIfMapping(body *hclwrite.Body, key string, valueNode *CandidateNode) bool {
+	if valueNode.Kind != MappingNode || valueNode.Style == FlowStyle {
+		return false
+	}
+
+	// If EncodeHintSeparateBlock is set, emit children as separate blocks regardless of label extraction
+	if valueNode.EncodeHint == EncodeHintSeparateBlock {
+		if handled, _ := he.encodeMappingChildrenAsBlocks(body, key, valueNode); handled {
+			return true
+		}
+	}
+
+	// Try to extract block labels from a single-entry mapping chain
+	if labels, bodyNode, ok := extractBlockLabels(valueNode); ok {
+		if len(labels) > 1 && mappingChildrenAllMappings(bodyNode) {
+			primaryLabels := labels[:len(labels)-1]
+			nestedType := labels[len(labels)-1]
+			block := body.AppendNewBlock(key, primaryLabels)
+			if handled, err := he.encodeMappingChildrenAsBlocks(block.Body(), nestedType, bodyNode); err == nil && handled {
+				return true
+			}
+			if err := he.encodeNodeAttributes(block.Body(), bodyNode); err == nil {
+				return true
+			}
+		}
+		block := body.AppendNewBlock(key, labels)
+		if err := he.encodeNodeAttributes(block.Body(), bodyNode); err == nil {
+			return true
+		}
+	}
+
+	// If all child values are mappings, treat each child key as a labelled instance of this block type
+	if handled, _ := he.encodeMappingChildrenAsBlocks(body, key, valueNode); handled {
+		return true
+	}
+
+	// No labels detected, render as unlabelled block
+	block := body.AppendNewBlock(key, nil)
+	if err := he.encodeNodeAttributes(block.Body(), valueNode); err == nil {
+		return true
+	}
+
+	return false
+}
+
+// encodeNode encodes a CandidateNode directly to HCL, preserving style information
+func (he *hclEncoder) encodeNode(body *hclwrite.Body, node *CandidateNode) error {
+	if node.Kind != MappingNode {
+		return fmt.Errorf("HCL encoder expects a mapping at the root level, got %v", kindToString(node.Kind))
+	}
+
+	for i := 0; i < len(node.Content); i += 2 {
+		keyNode := node.Content[i]
+		valueNode := node.Content[i+1]
+		key := keyNode.Value
+
+		// Render as block or attribute depending on value type
+		if he.encodeBlockIfMapping(body, key, valueNode) {
+			continue
+		}
+
+		// Render as attribute: key = value
+		if err := he.encodeAttribute(body, key, valueNode); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// mappingChildrenAllMappings reports whether all values in a mapping node are non-flow mappings.
+func mappingChildrenAllMappings(node *CandidateNode) bool {
+	if node == nil || node.Kind != MappingNode || node.Style == FlowStyle {
+		return false
+	}
+	if len(node.Content) == 0 {
+		return false
+	}
+	for i := 0; i < len(node.Content); i += 2 {
+		childVal := node.Content[i+1]
+		if childVal.Kind != MappingNode || childVal.Style == FlowStyle {
+			return false
+		}
+	}
+	return true
+}
+
+// encodeMappingChildrenAsBlocks emits a block for each mapping child, treating the child key as a label.
+// Returns handled=true when it emitted blocks.
+func (he *hclEncoder) encodeMappingChildrenAsBlocks(body *hclwrite.Body, blockType string, valueNode *CandidateNode) (bool, error) {
+	if !mappingChildrenAllMappings(valueNode) {
+		return false, nil
+	}
+
+	// Only emit as separate blocks if EncodeHintSeparateBlock is set
+	// This allows the encoder to respect the original block structure preserved by the decoder
+	if valueNode.EncodeHint != EncodeHintSeparateBlock {
+		return false, nil
+	}
+
+	for i := 0; i < len(valueNode.Content); i += 2 {
+		childKey := valueNode.Content[i].Value
+		childVal := valueNode.Content[i+1]
+
+		// Check if this child also represents multiple blocks (all children are mappings)
+		if mappingChildrenAllMappings(childVal) {
+			// Recursively emit each grandchild as a separate block with extended labels
+			for j := 0; j < len(childVal.Content); j += 2 {
+				grandchildKey := childVal.Content[j].Value
+				grandchildVal := childVal.Content[j+1]
+				labels := []string{childKey, grandchildKey}
+
+				// Try to extract additional labels if this is a single-entry chain
+				if extraLabels, bodyNode, ok := extractBlockLabels(grandchildVal); ok {
+					labels = append(labels, extraLabels...)
+					grandchildVal = bodyNode
+				}
+
+				block := body.AppendNewBlock(blockType, labels)
+				if err := he.encodeNodeAttributes(block.Body(), grandchildVal); err != nil {
+					return true, err
+				}
+			}
+		} else {
+			// Single block with this child as label(s)
+			labels := []string{childKey}
+			if extraLabels, bodyNode, ok := extractBlockLabels(childVal); ok {
+				labels = append(labels, extraLabels...)
+				childVal = bodyNode
+			}
+			block := body.AppendNewBlock(blockType, labels)
+			if err := he.encodeNodeAttributes(block.Body(), childVal); err != nil {
+				return true, err
+			}
+		}
+	}
+
+	return true, nil
+}
+
+// encodeNodeAttributes encodes the attributes of a mapping node (used for blocks)
+func (he *hclEncoder) encodeNodeAttributes(body *hclwrite.Body, node *CandidateNode) error {
+	if node.Kind != MappingNode {
+		return fmt.Errorf("expected mapping node for block body")
+	}
+
+	for i := 0; i < len(node.Content); i += 2 {
+		keyNode := node.Content[i]
+		valueNode := node.Content[i+1]
+		key := keyNode.Value
+
+		// Render as block or attribute depending on value type
+		if he.encodeBlockIfMapping(body, key, valueNode) {
+			continue
+		}
+
+		// Render attribute for non-block value
+		if err := he.encodeAttribute(body, key, valueNode); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// extractBlockLabels detects a chain of single-entry mappings that encode block labels.
+// It returns the collected labels and the final mapping to be used as the block body.
+// Pattern: {label1: {label2: { ... {bodyMap} }}}
+func extractBlockLabels(node *CandidateNode) ([]string, *CandidateNode, bool) {
+	var labels []string
+	current := node
+	for current != nil && current.Kind == MappingNode && len(current.Content) == 2 {
+		keyNode := current.Content[0]
+		valNode := current.Content[1]
+		if valNode.Kind != MappingNode {
+			break
+		}
+		labels = append(labels, keyNode.Value)
+		// If the child is itself a single mapping entry with a mapping value, keep descending.
+		if len(valNode.Content) == 2 && valNode.Content[1].Kind == MappingNode {
+			current = valNode
+			continue
+		}
+		// Otherwise, we have reached the body mapping.
+		return labels, valNode, true
+	}
+	return nil, nil, false
+}
+
+// nodeToCtyValue converts a CandidateNode directly to cty.Value, preserving order
+func nodeToCtyValue(node *CandidateNode) (cty.Value, error) {
+	switch node.Kind {
+	case ScalarNode:
+		// Parse scalar value based on its tag
+		switch node.Tag {
+		case "!!bool":
+			return cty.BoolVal(node.Value == "true"), nil
+		case "!!int":
+			var i int64
+			_, err := fmt.Sscanf(node.Value, "%d", &i)
+			if err != nil {
+				return cty.NilVal, err
+			}
+			return cty.NumberIntVal(i), nil
+		case "!!float":
+			var f float64
+			_, err := fmt.Sscanf(node.Value, "%f", &f)
+			if err != nil {
+				return cty.NilVal, err
+			}
+			return cty.NumberFloatVal(f), nil
+		case "!!null":
+			return cty.NullVal(cty.DynamicPseudoType), nil
+		default:
+			// Default to string
+			return cty.StringVal(node.Value), nil
+		}
+	case MappingNode:
+		// Preserve order by iterating Content directly
+		m := make(map[string]cty.Value)
+		for i := 0; i < len(node.Content); i += 2 {
+			keyNode := node.Content[i]
+			valueNode := node.Content[i+1]
+			v, err := nodeToCtyValue(valueNode)
+			if err != nil {
+				return cty.NilVal, err
+			}
+			m[keyNode.Value] = v
+		}
+		return cty.ObjectVal(m), nil
+	case SequenceNode:
+		vals := make([]cty.Value, len(node.Content))
+		for i, item := range node.Content {
+			v, err := nodeToCtyValue(item)
+			if err != nil {
+				return cty.NilVal, err
+			}
+			vals[i] = v
+		}
+		return cty.TupleVal(vals), nil
+	case AliasNode:
+		return cty.NilVal, fmt.Errorf("HCL encoder does not support aliases")
+	default:
+		return cty.NilVal, fmt.Errorf("unsupported node kind: %v", node.Kind)
+	}
+}

pkg/yqlib/encoder_kyaml.go

@@ -0,0 +1,318 @@
+//go:build !yq_nokyaml
+
+package yqlib
+
+import (
+	"bytes"
+	"io"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type kyamlEncoder struct {
+	prefs KYamlPreferences
+}
+
+func NewKYamlEncoder(prefs KYamlPreferences) Encoder {
+	return &kyamlEncoder{prefs: prefs}
+}
+
+func (ke *kyamlEncoder) CanHandleAliases() bool {
+	// KYAML is a restricted subset; avoid emitting anchors/aliases.
+	return false
+}
+
+func (ke *kyamlEncoder) PrintDocumentSeparator(writer io.Writer) error {
+	return PrintYAMLDocumentSeparator(writer, ke.prefs.PrintDocSeparators)
+}
+
+func (ke *kyamlEncoder) PrintLeadingContent(writer io.Writer, content string) error {
+	return PrintYAMLLeadingContent(writer, content, ke.prefs.PrintDocSeparators, ke.prefs.ColorsEnabled)
+}
+
+func (ke *kyamlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
+	log.Debugf("encoderKYaml - going to print %v", NodeToString(node))
+	if node.Kind == ScalarNode && ke.prefs.UnwrapScalar {
+		return writeString(writer, node.Value+"\n")
+	}
+
+	destination := writer
+	tempBuffer := bytes.NewBuffer(nil)
+	if ke.prefs.ColorsEnabled {
+		destination = tempBuffer
+	}
+
+	// Mirror the YAML encoder behaviour: trailing comments on the document root
+	// are stored in FootComment and need to be printed after the document.
+	trailingContent := node.FootComment
+
+	if err := ke.writeCommentBlock(destination, node.HeadComment, 0); err != nil {
+		return err
+	}
+	if err := ke.writeNode(destination, node, 0); err != nil {
+		return err
+	}
+	if err := ke.writeInlineComment(destination, node.LineComment); err != nil {
+		return err
+	}
+	if err := writeString(destination, "\n"); err != nil {
+		return err
+	}
+	if err := ke.PrintLeadingContent(destination, trailingContent); err != nil {
+		return err
+	}
+
+	if ke.prefs.ColorsEnabled {
+		return colorizeAndPrint(tempBuffer.Bytes(), writer)
+	}
+	return nil
+}
+
+func (ke *kyamlEncoder) writeNode(writer io.Writer, node *CandidateNode, indent int) error {
+	switch node.Kind {
+	case MappingNode:
+		return ke.writeMapping(writer, node, indent)
+	case SequenceNode:
+		return ke.writeSequence(writer, node, indent)
+	case ScalarNode:
+		return writeString(writer, ke.formatScalar(node))
+	case AliasNode:
+		// Should have been exploded by the printer, but handle defensively.
+		if node.Alias == nil {
+			return writeString(writer, "null")
+		}
+		return ke.writeNode(writer, node.Alias, indent)
+	default:
+		return writeString(writer, "null")
+	}
+}
+
+func (ke *kyamlEncoder) writeMapping(writer io.Writer, node *CandidateNode, indent int) error {
+	if len(node.Content) == 0 {
+		return writeString(writer, "{}")
+	}
+	if err := writeString(writer, "{\n"); err != nil {
+		return err
+	}
+
+	for i := 0; i+1 < len(node.Content); i += 2 {
+		keyNode := node.Content[i]
+		valueNode := node.Content[i+1]
+
+		entryIndent := indent + ke.prefs.Indent
+		if err := ke.writeCommentBlock(writer, keyNode.HeadComment, entryIndent); err != nil {
+			return err
+		}
+		if valueNode.HeadComment != "" && valueNode.HeadComment != keyNode.HeadComment {
+			if err := ke.writeCommentBlock(writer, valueNode.HeadComment, entryIndent); err != nil {
+				return err
+			}
+		}
+
+		if err := ke.writeIndent(writer, entryIndent); err != nil {
+			return err
+		}
+		if err := writeString(writer, ke.formatKey(keyNode)); err != nil {
+			return err
+		}
+		if err := writeString(writer, ": "); err != nil {
+			return err
+		}
+		if err := ke.writeNode(writer, valueNode, entryIndent); err != nil {
+			return err
+		}
+
+		// Always emit a trailing comma; KYAML encourages explicit separators,
+		// and this ensures all quoted strings have a trailing `",` as requested.
+		if err := writeString(writer, ","); err != nil {
+			return err
+		}
+		inline := valueNode.LineComment
+		if inline == "" {
+			inline = keyNode.LineComment
+		}
+		if err := ke.writeInlineComment(writer, inline); err != nil {
+			return err
+		}
+		if err := writeString(writer, "\n"); err != nil {
+			return err
+		}
+
+		foot := valueNode.FootComment
+		if foot == "" {
+			foot = keyNode.FootComment
+		}
+		if err := ke.writeCommentBlock(writer, foot, entryIndent); err != nil {
+			return err
+		}
+	}
+
+	if err := ke.writeIndent(writer, indent); err != nil {
+		return err
+	}
+	return writeString(writer, "}")
+}
+
+func (ke *kyamlEncoder) writeSequence(writer io.Writer, node *CandidateNode, indent int) error {
+	if len(node.Content) == 0 {
+		return writeString(writer, "[]")
+	}
+	if err := writeString(writer, "[\n"); err != nil {
+		return err
+	}
+
+	for _, child := range node.Content {
+		itemIndent := indent + ke.prefs.Indent
+		if err := ke.writeCommentBlock(writer, child.HeadComment, itemIndent); err != nil {
+			return err
+		}
+		if err := ke.writeIndent(writer, itemIndent); err != nil {
+			return err
+		}
+		if err := ke.writeNode(writer, child, itemIndent); err != nil {
+			return err
+		}
+		if err := writeString(writer, ","); err != nil {
+			return err
+		}
+		if err := ke.writeInlineComment(writer, child.LineComment); err != nil {
+			return err
+		}
+		if err := writeString(writer, "\n"); err != nil {
+			return err
+		}
+		if err := ke.writeCommentBlock(writer, child.FootComment, itemIndent); err != nil {
+			return err
+		}
+	}
+
+	if err := ke.writeIndent(writer, indent); err != nil {
+		return err
+	}
+	return writeString(writer, "]")
+}
+
+func (ke *kyamlEncoder) writeIndent(writer io.Writer, indent int) error {
+	if indent <= 0 {
+		return nil
+	}
+	return writeString(writer, strings.Repeat(" ", indent))
+}
+
+func (ke *kyamlEncoder) formatKey(keyNode *CandidateNode) string {
+	// KYAML examples use bare keys. Quote keys only when needed.
+	key := keyNode.Value
+	if isValidKYamlBareKey(key) {
+		return key
+	}
+	return `"` + escapeDoubleQuotedString(key) + `"`
+}
+
+func (ke *kyamlEncoder) formatScalar(node *CandidateNode) string {
+	switch node.Tag {
+	case "!!null":
+		return "null"
+	case "!!bool":
+		return strings.ToLower(node.Value)
+	case "!!int", "!!float":
+		return node.Value
+	case "!!str":
+		return `"` + escapeDoubleQuotedString(node.Value) + `"`
+	default:
+		// Fall back to a string representation to avoid implicit typing surprises.
+		return `"` + escapeDoubleQuotedString(node.Value) + `"`
+	}
+}
+
+var kyamlBareKeyRe = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_-]*$`)
+
+func isValidKYamlBareKey(s string) bool {
+	// Conservative: require an identifier-like key; otherwise quote.
+	if s == "" {
+		return false
+	}
+	return kyamlBareKeyRe.MatchString(s)
+}
+
+func escapeDoubleQuotedString(s string) string {
+	var b strings.Builder
+	b.Grow(len(s) + 2)
+
+	for _, r := range s {
+		switch r {
+		case '\\':
+			b.WriteString(`\\`)
+		case '"':
+			b.WriteString(`\"`)
+		case '\n':
+			b.WriteString(`\n`)
+		case '\r':
+			b.WriteString(`\r`)
+		case '\t':
+			b.WriteString(`\t`)
+		default:
+			if r < 0x20 {
+				// YAML double-quoted strings support \uXXXX escapes.
+				b.WriteString(`\u`)
+				hex := "0000" + strings.ToUpper(strconv.FormatInt(int64(r), 16))
+				b.WriteString(hex[len(hex)-4:])
+			} else {
+				b.WriteRune(r)
+			}
+		}
+	}
+	return b.String()
+}
+
+func (ke *kyamlEncoder) writeCommentBlock(writer io.Writer, comment string, indent int) error {
+	if strings.TrimSpace(comment) == "" {
+		return nil
+	}
+
+	lines := strings.Split(strings.ReplaceAll(comment, "\r\n", "\n"), "\n")
+	for _, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "" {
+			continue
+		}
+
+		if err := ke.writeIndent(writer, indent); err != nil {
+			return err
+		}
+
+		toWrite := line
+		if !commentLineRe.MatchString(toWrite) {
+			toWrite = "# " + toWrite
+		}
+		if err := writeString(writer, toWrite); err != nil {
+			return err
+		}
+		if err := writeString(writer, "\n"); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (ke *kyamlEncoder) writeInlineComment(writer io.Writer, comment string) error {
+	comment = strings.TrimSpace(strings.ReplaceAll(comment, "\r\n", "\n"))
+	if comment == "" {
+		return nil
+	}
+
+	lines := strings.Split(comment, "\n")
+	first := strings.TrimSpace(lines[0])
+	if first == "" {
+		return nil
+	}
+
+	if !strings.HasPrefix(first, "#") {
+		first = "# " + first
+	}
+
+	if err := writeString(writer, " "); err != nil {
+		return err
+	}
+	return writeString(writer, first)
+}

pkg/yqlib/encoder_shellvariables.go

@@ -57,7 +57,13 @@ func (pe *shellVariablesEncoder) doEncode(w *io.Writer, node *CandidateNode, pat
 			// let's just pick a fallback key to use if we are encoding a single scalar
 			nonemptyPath = "value"
 		}
-		_, err := io.WriteString(*w, nonemptyPath+"="+quoteValue(node.Value)+"\n")
+		var valueString string
+		if pe.prefs.UnwrapScalar {
+			valueString = node.Value
+		} else {
+			valueString = quoteValue(node.Value)
+		}
+		_, err := io.WriteString(*w, nonemptyPath+"="+valueString+"\n")
 		return err
 	case SequenceNode:
 		for index, child := range node.Content {

pkg/yqlib/encoder_shellvariables_test.go

@@ -135,3 +135,36 @@ func TestShellVariablesEncoderCustomSeparatorArray(t *testing.T) {
 func TestShellVariablesEncoderCustomSeparatorSingleChar(t *testing.T) {
 	assertEncodesToWithSeparator(t, "a:\n b: value", "aXb=value", "X")
 }
+
+func assertEncodesToUnwrapped(t *testing.T, yaml string, shellvars string) {
+	var output bytes.Buffer
+	writer := bufio.NewWriter(&output)
+
+	originalUnwrapScalar := ConfiguredShellVariablesPreferences.UnwrapScalar
+	defer func() {
+		ConfiguredShellVariablesPreferences.UnwrapScalar = originalUnwrapScalar
+	}()
+
+	ConfiguredShellVariablesPreferences.UnwrapScalar = true
+
+	var encoder = NewShellVariablesEncoder()
+	inputs, err := readDocuments(strings.NewReader(yaml), "test.yml", 0, NewYamlDecoder(ConfiguredYamlPreferences))
+	if err != nil {
+		panic(err)
+	}
+	node := inputs.Front().Value.(*CandidateNode)
+	err = encoder.Encode(writer, node)
+	if err != nil {
+		panic(err)
+	}
+	writer.Flush()
+
+	test.AssertResult(t, shellvars, strings.TrimSuffix(output.String(), "\n"))
+}
+
+func TestShellVariablesEncoderUnwrapScalar(t *testing.T) {
+	assertEncodesToUnwrapped(t, "a: Lewis Carroll", "a=Lewis Carroll")
+	assertEncodesToUnwrapped(t, "b: 123", "b=123")
+	assertEncodesToUnwrapped(t, "c: true", "c=true")
+	assertEncodesToUnwrapped(t, "d: value with spaces", "d=value with spaces")
+}

pkg/yqlib/encoder_toml.go

@@ -1,22 +1,58 @@
+//go:build !yq_notoml
+
 package yqlib
 
 import (
+	"bytes"
 	"fmt"
 	"io"
+	"strings"
+
+	"github.com/fatih/color"
 )
 
 type tomlEncoder struct {
+	wroteRootAttr bool // Track if we wrote root-level attributes before tables
+	prefs         TomlPreferences
 }
 
 func NewTomlEncoder() Encoder {
-	return &tomlEncoder{}
+	return NewTomlEncoderWithPrefs(ConfiguredTomlPreferences)
+}
+
+func NewTomlEncoderWithPrefs(prefs TomlPreferences) Encoder {
+	return &tomlEncoder{prefs: prefs}
 }
 
 func (te *tomlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
-	if node.Kind == ScalarNode {
-		return writeString(writer, node.Value+"\n")
+	if node.Kind != MappingNode {
+		// For standalone selections, TOML tests expect raw value for scalars
+		if node.Kind == ScalarNode {
+			return writeString(writer, node.Value+"\n")
+		}
+		return fmt.Errorf("TOML encoder expects a mapping at the root level")
 	}
-	return fmt.Errorf("only scalars (e.g. strings, numbers, booleans) are supported for TOML output at the moment. Please use yaml output format (-oy) until the encoder has been fully implemented")
+
+	// Encode to a buffer first if colors are enabled
+	var buf bytes.Buffer
+	var targetWriter io.Writer
+	targetWriter = writer
+	if te.prefs.ColorsEnabled {
+		targetWriter = &buf
+	}
+
+	// Encode a root mapping as a sequence of attributes, tables, and arrays of tables
+	if err := te.encodeRootMapping(targetWriter, node); err != nil {
+		return err
+	}
+
+	if te.prefs.ColorsEnabled {
+		colourised := te.colorizeToml(buf.Bytes())
+		_, err := writer.Write(colourised)
+		return err
+	}
+
+	return nil
 }
 
 func (te *tomlEncoder) PrintDocumentSeparator(_ io.Writer) error {
@@ -30,3 +66,720 @@ func (te *tomlEncoder) PrintLeadingContent(_ io.Writer, _ string) error {
 func (te *tomlEncoder) CanHandleAliases() bool {
 	return false
 }
+
+// ---- helpers ----
+
+// tomlKey returns the key quoted if it contains characters that are not valid
+// in a TOML bare key. TOML bare keys may only contain ASCII letters, ASCII
+// digits, underscores, and dashes.
+func tomlKey(key string) string {
+	for _, r := range key {
+		if (r < 'A' || r > 'Z') && (r < 'a' || r > 'z') && (r < '0' || r > '9') && r != '_' && r != '-' {
+			return fmt.Sprintf("%q", key)
+		}
+	}
+	return key
+}
+
+// tomlDottedKey joins path components, quoting any that require it.
+func tomlDottedKey(path []string) string {
+	parts := make([]string, len(path))
+	for i, p := range path {
+		parts[i] = tomlKey(p)
+	}
+	return strings.Join(parts, ".")
+}
+
+func (te *tomlEncoder) writeComment(w io.Writer, comment string) error {
+	if comment == "" {
+		return nil
+	}
+	lines := strings.Split(comment, "\n")
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if !strings.HasPrefix(line, "#") {
+			line = "# " + line
+		}
+		if _, err := w.Write([]byte(line + "\n")); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (te *tomlEncoder) formatScalar(node *CandidateNode) string {
+	switch node.Tag {
+	case "!!str":
+		// Quote strings per TOML spec
+		return fmt.Sprintf("%q", node.Value)
+	case "!!bool", "!!int", "!!float":
+		return node.Value
+	case "!!null":
+		// TOML does not have null; encode as empty string
+		return `""`
+	default:
+		return node.Value
+	}
+}
+
+func (te *tomlEncoder) encodeRootMapping(w io.Writer, node *CandidateNode) error {
+	te.wroteRootAttr = false // Reset state
+
+	// Write root head comment if present (at the very beginning, no leading blank line)
+	if node.HeadComment != "" {
+		if err := te.writeComment(w, node.HeadComment); err != nil {
+			return err
+		}
+	}
+
+	// Preserve existing order by iterating Content
+	for i := 0; i < len(node.Content); i += 2 {
+		keyNode := node.Content[i]
+		valNode := node.Content[i+1]
+		if err := te.encodeTopLevelEntry(w, []string{keyNode.Value}, valNode); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// encodeTopLevelEntry encodes a key/value at the root, dispatching to attribute, table, or array-of-tables
+func (te *tomlEncoder) encodeTopLevelEntry(w io.Writer, path []string, node *CandidateNode) error {
+	if len(path) == 0 {
+		return fmt.Errorf("cannot encode TOML entry with empty path")
+	}
+
+	switch node.Kind {
+	case ScalarNode:
+		// key = value
+		return te.writeAttribute(w, path[len(path)-1], node)
+	case SequenceNode:
+		// Empty arrays should be encoded as [] attributes
+		if len(node.Content) == 0 {
+			return te.writeArrayAttribute(w, path[len(path)-1], node)
+		}
+
+		// If all items are mappings => array of tables; else => array attribute
+		allMaps := true
+		for _, it := range node.Content {
+			if it.Kind != MappingNode {
+				allMaps = false
+				break
+			}
+		}
+		if allMaps {
+			key := path[len(path)-1]
+			quotedKey := tomlKey(key)
+			for _, it := range node.Content {
+				// [[key]] then body
+				if _, err := w.Write([]byte("[[" + quotedKey + "]]\n")); err != nil {
+					return err
+				}
+				if err := te.encodeMappingBodyWithPath(w, []string{key}, it); err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+		// Regular array attribute
+		return te.writeArrayAttribute(w, path[len(path)-1], node)
+	case MappingNode:
+		// Use inline table syntax for nodes explicitly marked as TOML inline tables
+		// or YAML flow mappings. All other mappings become readable TOML table sections.
+		if node.EncodeHint == EncodeHintInline || node.Style&FlowStyle != 0 {
+			return te.writeInlineTableAttribute(w, path[len(path)-1], node)
+		}
+		return te.encodeSeparateMapping(w, path, node)
+	default:
+		return fmt.Errorf("unsupported node kind for TOML: %v", node.Kind)
+	}
+}
+
+func (te *tomlEncoder) writeAttribute(w io.Writer, key string, value *CandidateNode) error {
+	te.wroteRootAttr = true // Mark that we wrote a root attribute
+
+	// Write head comment before the attribute
+	if err := te.writeComment(w, value.HeadComment); err != nil {
+		return err
+	}
+
+	// Write the attribute
+	line := tomlKey(key) + " = " + te.formatScalar(value)
+
+	// Add line comment if present
+	if value.LineComment != "" {
+		lineComment := strings.TrimSpace(value.LineComment)
+		if !strings.HasPrefix(lineComment, "#") {
+			lineComment = "# " + lineComment
+		}
+		line += "  " + lineComment
+	}
+
+	_, err := w.Write([]byte(line + "\n"))
+	return err
+}
+
+func (te *tomlEncoder) writeArrayAttribute(w io.Writer, key string, seq *CandidateNode) error {
+	te.wroteRootAttr = true // Mark that we wrote a root attribute
+
+	// Write head comment before the array
+	if err := te.writeComment(w, seq.HeadComment); err != nil {
+		return err
+	}
+
+	// Handle empty arrays
+	if len(seq.Content) == 0 {
+		line := tomlKey(key) + " = []"
+		if seq.LineComment != "" {
+			lineComment := strings.TrimSpace(seq.LineComment)
+			if !strings.HasPrefix(lineComment, "#") {
+				lineComment = "# " + lineComment
+			}
+			line += "  " + lineComment
+		}
+		_, err := w.Write([]byte(line + "\n"))
+		return err
+	}
+
+	// Check if any array elements have head comments - if so, use multiline format
+	hasElementComments := false
+	for _, it := range seq.Content {
+		if it.HeadComment != "" {
+			hasElementComments = true
+			break
+		}
+	}
+
+	if hasElementComments {
+		// Write multiline array format with comments
+		if _, err := w.Write([]byte(tomlKey(key) + " = [\n")); err != nil {
+			return err
+		}
+
+		for i, it := range seq.Content {
+			// Write head comment for this element
+			if it.HeadComment != "" {
+				commentLines := strings.Split(it.HeadComment, "\n")
+				for _, commentLine := range commentLines {
+					if strings.TrimSpace(commentLine) != "" {
+						if !strings.HasPrefix(strings.TrimSpace(commentLine), "#") {
+							commentLine = "# " + commentLine
+						}
+						if _, err := w.Write([]byte("  " + commentLine + "\n")); err != nil {
+							return err
+						}
+					}
+				}
+			}
+
+			// Write the element value
+			var itemStr string
+			switch it.Kind {
+			case ScalarNode:
+				itemStr = te.formatScalar(it)
+			case SequenceNode:
+				nested, err := te.sequenceToInlineArray(it)
+				if err != nil {
+					return err
+				}
+				itemStr = nested
+			case MappingNode:
+				inline, err := te.mappingToInlineTable(it)
+				if err != nil {
+					return err
+				}
+				itemStr = inline
+			case AliasNode:
+				return fmt.Errorf("aliases are not supported in TOML")
+			default:
+				return fmt.Errorf("unsupported array item kind: %v", it.Kind)
+			}
+
+			// Always add trailing comma in multiline arrays
+			itemStr += ","
+
+			if _, err := w.Write([]byte("  " + itemStr + "\n")); err != nil {
+				return err
+			}
+
+			// Add blank line between elements (except after the last one)
+			if i < len(seq.Content)-1 {
+				if _, err := w.Write([]byte("\n")); err != nil {
+					return err
+				}
+			}
+		}
+
+		if _, err := w.Write([]byte("]\n")); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	// Join scalars or nested arrays recursively into TOML array syntax
+	items := make([]string, 0, len(seq.Content))
+	for _, it := range seq.Content {
+		switch it.Kind {
+		case ScalarNode:
+			items = append(items, te.formatScalar(it))
+		case SequenceNode:
+			// Nested arrays: encode inline
+			nested, err := te.sequenceToInlineArray(it)
+			if err != nil {
+				return err
+			}
+			items = append(items, nested)
+		case MappingNode:
+			// Inline table inside array
+			inline, err := te.mappingToInlineTable(it)
+			if err != nil {
+				return err
+			}
+			items = append(items, inline)
+		case AliasNode:
+			return fmt.Errorf("aliases are not supported in TOML")
+		default:
+			return fmt.Errorf("unsupported array item kind: %v", it.Kind)
+		}
+	}
+
+	line := tomlKey(key) + " = [" + strings.Join(items, ", ") + "]"
+
+	// Add line comment if present
+	if seq.LineComment != "" {
+		lineComment := strings.TrimSpace(seq.LineComment)
+		if !strings.HasPrefix(lineComment, "#") {
+			lineComment = "# " + lineComment
+		}
+		line += "  " + lineComment
+	}
+
+	_, err := w.Write([]byte(line + "\n"))
+	return err
+}
+
+func (te *tomlEncoder) sequenceToInlineArray(seq *CandidateNode) (string, error) {
+	items := make([]string, 0, len(seq.Content))
+	for _, it := range seq.Content {
+		switch it.Kind {
+		case ScalarNode:
+			items = append(items, te.formatScalar(it))
+		case SequenceNode:
+			nested, err := te.sequenceToInlineArray(it)
+			if err != nil {
+				return "", err
+			}
+			items = append(items, nested)
+		case MappingNode:
+			inline, err := te.mappingToInlineTable(it)
+			if err != nil {
+				return "", err
+			}
+			items = append(items, inline)
+		default:
+			return "", fmt.Errorf("unsupported array item kind: %v", it.Kind)
+		}
+	}
+	return "[" + strings.Join(items, ", ") + "]", nil
+}
+
+func (te *tomlEncoder) mappingToInlineTable(m *CandidateNode) (string, error) {
+	// key = { a = 1, b = "x" }
+	parts := make([]string, 0, len(m.Content)/2)
+	for i := 0; i < len(m.Content); i += 2 {
+		k := m.Content[i].Value
+		v := m.Content[i+1]
+		switch v.Kind {
+		case ScalarNode:
+			parts = append(parts, fmt.Sprintf("%s = %s", tomlKey(k), te.formatScalar(v)))
+		case SequenceNode:
+			// inline array in inline table
+			arr, err := te.sequenceToInlineArray(v)
+			if err != nil {
+				return "", err
+			}
+			parts = append(parts, fmt.Sprintf("%s = %s", tomlKey(k), arr))
+		case MappingNode:
+			// nested inline table
+			inline, err := te.mappingToInlineTable(v)
+			if err != nil {
+				return "", err
+			}
+			parts = append(parts, fmt.Sprintf("%s = %s", tomlKey(k), inline))
+		default:
+			return "", fmt.Errorf("unsupported inline table value kind: %v", v.Kind)
+		}
+	}
+	return "{ " + strings.Join(parts, ", ") + " }", nil
+}
+
+func (te *tomlEncoder) writeInlineTableAttribute(w io.Writer, key string, m *CandidateNode) error {
+	inline, err := te.mappingToInlineTable(m)
+	if err != nil {
+		return err
+	}
+	_, err = w.Write([]byte(tomlKey(key) + " = " + inline + "\n"))
+	return err
+}
+
+func (te *tomlEncoder) writeTableHeader(w io.Writer, path []string, m *CandidateNode) error {
+	// Add blank line before table header (or before comment if present) if we wrote root attributes
+	needsBlankLine := te.wroteRootAttr
+	if needsBlankLine {
+		if _, err := w.Write([]byte("\n")); err != nil {
+			return err
+		}
+		te.wroteRootAttr = false // Only add once
+	}
+
+	// Write head comment before the table header
+	if m.HeadComment != "" {
+		if err := te.writeComment(w, m.HeadComment); err != nil {
+			return err
+		}
+	}
+
+	// Write table header [a.b.c]
+	header := "[" + tomlDottedKey(path) + "]\n"
+	_, err := w.Write([]byte(header))
+	return err
+}
+
+// encodeSeparateMapping handles a mapping that should be encoded as table sections.
+// It emits the table header for this mapping if it has any content, then processes children.
+func (te *tomlEncoder) encodeSeparateMapping(w io.Writer, path []string, m *CandidateNode) error {
+	// Check if this mapping has any non-mapping, non-array-of-tables children (i.e., attributes).
+	// Inline mapping children also count as attributes since they render as key = { ... }.
+	hasAttrs := false
+	for i := 0; i < len(m.Content); i += 2 {
+		v := m.Content[i+1]
+		if v.Kind == ScalarNode {
+			hasAttrs = true
+			break
+		}
+		if v.Kind == MappingNode && (v.EncodeHint == EncodeHintInline || v.Style&FlowStyle != 0) {
+			hasAttrs = true
+			break
+		}
+		if v.Kind == SequenceNode {
+			// Check if it's NOT an array of tables
+			allMaps := true
+			for _, it := range v.Content {
+				if it.Kind != MappingNode {
+					allMaps = false
+					break
+				}
+			}
+			if !allMaps {
+				hasAttrs = true
+				break
+			}
+		}
+	}
+
+	// If there are attributes or if the mapping is empty, emit the table header
+	if hasAttrs || len(m.Content) == 0 {
+		if err := te.writeTableHeader(w, path, m); err != nil {
+			return err
+		}
+		if err := te.encodeMappingBodyWithPath(w, path, m); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	// No attributes, just nested table structures - process children recursively
+	for i := 0; i < len(m.Content); i += 2 {
+		k := m.Content[i].Value
+		v := m.Content[i+1]
+		switch v.Kind {
+		case MappingNode:
+			newPath := append(append([]string{}, path...), k)
+			if err := te.encodeSeparateMapping(w, newPath, v); err != nil {
+				return err
+			}
+		case SequenceNode:
+			// If sequence of maps, emit [[path.k]] per element
+			allMaps := true
+			for _, it := range v.Content {
+				if it.Kind != MappingNode {
+					allMaps = false
+					break
+				}
+			}
+			if allMaps {
+				key := tomlDottedKey(append(append([]string{}, path...), k))
+				for _, it := range v.Content {
+					if _, err := w.Write([]byte("[[" + key + "]]\n")); err != nil {
+						return err
+					}
+					if err := te.encodeMappingBodyWithPath(w, append(append([]string{}, path...), k), it); err != nil {
+						return err
+					}
+				}
+			} else {
+				// Regular array attribute under the current table path
+				if err := te.writeArrayAttribute(w, k, v); err != nil {
+					return err
+				}
+			}
+		case ScalarNode:
+			// Attributes directly under the current table path
+			if err := te.writeAttribute(w, k, v); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// encodeMappingBodyWithPath encodes attributes and nested arrays of tables using full dotted path context
+func (te *tomlEncoder) encodeMappingBodyWithPath(w io.Writer, path []string, m *CandidateNode) error {
+	// First, attributes (scalars and non-map arrays)
+	for i := 0; i < len(m.Content); i += 2 {
+		k := m.Content[i].Value
+		v := m.Content[i+1]
+		switch v.Kind {
+		case ScalarNode:
+			if err := te.writeAttribute(w, k, v); err != nil {
+				return err
+			}
+		case SequenceNode:
+			allMaps := true
+			for _, it := range v.Content {
+				if it.Kind != MappingNode {
+					allMaps = false
+					break
+				}
+			}
+			if !allMaps {
+				if err := te.writeArrayAttribute(w, k, v); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	// Then, nested arrays of tables with full path
+	for i := 0; i < len(m.Content); i += 2 {
+		k := m.Content[i].Value
+		v := m.Content[i+1]
+		if v.Kind == SequenceNode {
+			allMaps := true
+			for _, it := range v.Content {
+				if it.Kind != MappingNode {
+					allMaps = false
+					break
+				}
+			}
+			if allMaps {
+				dotted := tomlDottedKey(append(append([]string{}, path...), k))
+				for _, it := range v.Content {
+					if _, err := w.Write([]byte("[[" + dotted + "]]\n")); err != nil {
+						return err
+					}
+					if err := te.encodeMappingBodyWithPath(w, append(append([]string{}, path...), k), it); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+
+	// Finally, child mappings: inline-hint or flow-style ones become inline table attributes,
+	// while all others are emitted as separate sub-table sections.
+	for i := 0; i < len(m.Content); i += 2 {
+		k := m.Content[i].Value
+		v := m.Content[i+1]
+		if v.Kind == MappingNode {
+			if v.EncodeHint == EncodeHintInline || v.Style&FlowStyle != 0 {
+				if err := te.writeInlineTableAttribute(w, k, v); err != nil {
+					return err
+				}
+			} else {
+				subPath := append(append([]string{}, path...), k)
+				if err := te.encodeSeparateMapping(w, subPath, v); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// colorizeToml applies syntax highlighting to TOML output using fatih/color
+func (te *tomlEncoder) colorizeToml(input []byte) []byte {
+	toml := string(input)
+	result := strings.Builder{}
+
+	// Force color output (don't check for TTY)
+	color.NoColor = false
+
+	// Create color functions for different token types
+	// Use EnableColor() to ensure colors work even when NO_COLOR env is set
+	commentColorObj := color.New(color.FgHiBlack)
+	commentColorObj.EnableColor()
+	stringColorObj := color.New(color.FgGreen)
+	stringColorObj.EnableColor()
+	numberColorObj := color.New(color.FgHiMagenta)
+	numberColorObj.EnableColor()
+	keyColorObj := color.New(color.FgCyan)
+	keyColorObj.EnableColor()
+	boolColorObj := color.New(color.FgHiMagenta)
+	boolColorObj.EnableColor()
+	sectionColorObj := color.New(color.FgYellow, color.Bold)
+	sectionColorObj.EnableColor()
+
+	commentColor := commentColorObj.SprintFunc()
+	stringColor := stringColorObj.SprintFunc()
+	numberColor := numberColorObj.SprintFunc()
+	keyColor := keyColorObj.SprintFunc()
+	boolColor := boolColorObj.SprintFunc()
+	sectionColor := sectionColorObj.SprintFunc()
+
+	// Simple tokenization for TOML colouring
+	i := 0
+	for i < len(toml) {
+		ch := toml[i]
+
+		// Comments - from # to end of line
+		if ch == '#' {
+			end := i
+			for end < len(toml) && toml[end] != '\n' {
+				end++
+			}
+			result.WriteString(commentColor(toml[i:end]))
+			i = end
+			continue
+		}
+
+		// Table sections - [section] or [[array]]
+		// Only treat '[' as a table section if it appears at the start of the line
+		// (possibly after whitespace). This avoids mis-colouring inline arrays like
+		// "ports = [8000, 8001]" as table sections.
+		if ch == '[' {
+			isSectionHeader := true
+			if i > 0 {
+				isSectionHeader = false
+				j := i - 1
+				for j >= 0 && toml[j] != '\n' {
+					if toml[j] != ' ' && toml[j] != '\t' && toml[j] != '\r' {
+						// Found a non-whitespace character before this '[' on the same line,
+						// so this is not a table header.
+						break
+					}
+					j--
+				}
+				if j < 0 || toml[j] == '\n' {
+					// Reached the start of the string or a newline without encountering
+					// any non-whitespace, so '[' is at the logical start of the line.
+					isSectionHeader = true
+				}
+			}
+			if isSectionHeader {
+				end := i + 1
+				// Check for [[
+				if end < len(toml) && toml[end] == '[' {
+					end++
+				}
+				// Find closing ]
+				for end < len(toml) && toml[end] != ']' {
+					end++
+				}
+				// Include closing ]
+				if end < len(toml) {
+					end++
+					// Check for ]]
+					if end < len(toml) && toml[end] == ']' {
+						end++
+					}
+				}
+				result.WriteString(sectionColor(toml[i:end]))
+				i = end
+				continue
+			}
+		}
+
+		// Strings - quoted text (double or single quotes)
+		if ch == '"' || ch == '\'' {
+			quote := ch
+			end := i + 1
+			for end < len(toml) {
+				if toml[end] == quote {
+					break
+				}
+				if toml[end] == '\\' && end+1 < len(toml) {
+					// Skip the backslash and the escaped character
+					end += 2
+					continue
+				}
+				end++
+			}
+			if end < len(toml) {
+				end++ // include closing quote
+			}
+			result.WriteString(stringColor(toml[i:end]))
+			i = end
+			continue
+		}
+
+		// Numbers - sequences of digits, possibly with decimal point or minus
+		if (ch >= '0' && ch <= '9') || (ch == '-' && i+1 < len(toml) && toml[i+1] >= '0' && toml[i+1] <= '9') {
+			end := i
+			if ch == '-' {
+				end++
+			}
+			for end < len(toml) {
+				c := toml[end]
+				if (c >= '0' && c <= '9') || c == '.' || c == 'e' || c == 'E' {
+					end++
+				} else if (c == '+' || c == '-') && end > 0 && (toml[end-1] == 'e' || toml[end-1] == 'E') {
+					// Only allow + or - immediately after 'e' or 'E' for scientific notation
+					end++
+				} else {
+					break
+				}
+			}
+			result.WriteString(numberColor(toml[i:end]))
+			i = end
+			continue
+		}
+
+		// Identifiers/keys - alphanumeric + underscore + dash
+		if (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || ch == '_' {
+			end := i
+			for end < len(toml) && ((toml[end] >= 'a' && toml[end] <= 'z') ||
+				(toml[end] >= 'A' && toml[end] <= 'Z') ||
+				(toml[end] >= '0' && toml[end] <= '9') ||
+				toml[end] == '_' || toml[end] == '-') {
+				end++
+			}
+			ident := toml[i:end]
+
+			// Check if this is a boolean/null keyword
+			switch ident {
+			case "true", "false":
+				result.WriteString(boolColor(ident))
+			default:
+				// Check if followed by = or whitespace then = (it's a key)
+				j := end
+				for j < len(toml) && (toml[j] == ' ' || toml[j] == '\t') {
+					j++
+				}
+				if j < len(toml) && toml[j] == '=' {
+					result.WriteString(keyColor(ident))
+				} else {
+					result.WriteString(ident) // plain text for other identifiers
+				}
+			}
+			i = end
+			continue
+		}
+
+		// Everything else (whitespace, operators, brackets) - no color
+		result.WriteByte(ch)
+		i++
+	}
+
+	return []byte(result.String())
+}

pkg/yqlib/encoder_xml.go

@@ -59,7 +59,7 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 					return err
 				}
 				if _, err := e.writer.Write([]byte("\n")); err != nil {
-					log.Warning("Unable to write newline, skipping: %w", err)
+					log.Warningf("Unable to write newline, skipping: %v", err)
 				}
 			}
 		}
@@ -131,7 +131,7 @@ func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *CandidateNode
 				return err
 			}
 			if _, err := e.writer.Write([]byte("\n")); err != nil {
-				log.Warning("Unable to write newline, skipping: %w", err)
+				log.Warningf("Unable to write newline, skipping: %v", err)
 			}
 		} else if key.Value == e.prefs.DirectiveName {
 			var directive xml.Directive = []byte(value.Value)
@@ -139,7 +139,7 @@ func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *CandidateNode
 				return err
 			}
 			if _, err := e.writer.Write([]byte("\n")); err != nil {
-				log.Warning("Unable to write newline, skipping: %w", err)
+				log.Warningf("Unable to write newline, skipping: %v", err)
 			}
 		} else {
 

pkg/yqlib/encoder_yaml.go

@@ -1,13 +1,10 @@
 package yqlib
 
 import (
-	"bufio"
 	"bytes"
-	"errors"
 	"io"
 	"strings"
 
-	"github.com/fatih/color"
 	"go.yaml.in/yaml/v4"
 )
 
@@ -24,67 +21,15 @@ func (ye *yamlEncoder) CanHandleAliases() bool {
 }
 
 func (ye *yamlEncoder) PrintDocumentSeparator(writer io.Writer) error {
-	if ye.prefs.PrintDocSeparators {
-		log.Debug("writing doc sep")
-		if err := writeString(writer, "---\n"); err != nil {
-			return err
-		}
-	}
-	return nil
+	return PrintYAMLDocumentSeparator(writer, ye.prefs.PrintDocSeparators)
 }
 
 func (ye *yamlEncoder) PrintLeadingContent(writer io.Writer, content string) error {
-	reader := bufio.NewReader(strings.NewReader(content))
-
-	// reuse precompiled package-level regex
-	// (declared in decoder_yaml.go)
-
-	for {
-
-		readline, errReading := reader.ReadString('\n')
-		if errReading != nil && !errors.Is(errReading, io.EOF) {
-			return errReading
-		}
-		if strings.Contains(readline, "$yqDocSeparator$") {
-			// Preserve the original line ending (CRLF or LF)
-			lineEnding := "\n"
-			if strings.HasSuffix(readline, "\r\n") {
-				lineEnding = "\r\n"
-			}
-			if ye.prefs.PrintDocSeparators {
-				if err := writeString(writer, "---"+lineEnding); err != nil {
-					return err
-				}
-			}
-
-		} else {
-			if len(readline) > 0 && readline != "\n" && readline[0] != '%' && !commentLineRe.MatchString(readline) {
-				readline = "# " + readline
-			}
-			if ye.prefs.ColorsEnabled && strings.TrimSpace(readline) != "" {
-				readline = format(color.FgHiBlack) + readline + format(color.Reset)
-			}
-			if err := writeString(writer, readline); err != nil {
-				return err
-			}
-		}
-
-		if errors.Is(errReading, io.EOF) {
-			if readline != "" {
-				// the last comment we read didn't have a newline, put one in
-				if err := writeString(writer, "\n"); err != nil {
-					return err
-				}
-			}
-			break
-		}
-	}
-
-	return nil
+	return PrintYAMLLeadingContent(writer, content, ye.prefs.PrintDocSeparators, ye.prefs.ColorsEnabled)
 }
 
 func (ye *yamlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
-	log.Debug("encoderYaml - going to print %v", NodeToString(node))
+	log.Debugf("encoderYaml - going to print %v", NodeToString(node))
 	// Detect line ending style from LeadingContent
 	lineEnding := "\n"
 	if strings.Contains(node.LeadingContent, "\r\n") {
@@ -107,6 +52,9 @@ func (ye *yamlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 	var encoder = yaml.NewEncoder(destination)
 
 	encoder.SetIndent(ye.prefs.Indent)
+	if ye.prefs.CompactSequenceIndent {
+		encoder.CompactSeqIndent()
+	}
 
 	target, err := node.MarshalYAML()
 

pkg/yqlib/expression_parser.go

@@ -26,7 +26,7 @@ func newExpressionParser() ExpressionParserInterface {
 }
 
 func (p *expressionParserImpl) ParseExpression(expression string) (*ExpressionNode, error) {
-	log.Debug("Parsing expression: [%v]", expression)
+	log.Debugf("Parsing expression: [%v]", expression)
 	tokens, err := p.pathTokeniser.Tokenise(expression)
 	if err != nil {
 		return nil, err

pkg/yqlib/expression_parser_test.go

@@ -95,6 +95,7 @@ func TestParserSingleOperation(t *testing.T) {
 	test.AssertResultComplex(t, nil, err)
 	if result == nil {
 		t.Fatal("Expected non-nil result for single operation")
+		return
 	}
 	if result.Operation == nil {
 		t.Fatal("Expected operation to be set")

pkg/yqlib/expression_postfix.go

@@ -3,8 +3,7 @@ package yqlib
 import (
 	"errors"
 	"fmt"
-
-	logging "gopkg.in/op/go-logging.v1"
+	"log/slog"
 )
 
 type expressionPostFixer interface {
@@ -134,7 +133,7 @@ func (p *expressionPostFixerImpl) ConvertToPostfix(infixTokens []*token) ([]*Ope
 		return nil, fmt.Errorf("bad expression - probably missing close bracket on %v", opStack[len(opStack)-1].toString(false))
 	}
 
-	if log.IsEnabledFor(logging.DEBUG) {
+	if log.IsEnabledFor(slog.LevelDebug) {
 		log.Debugf("PostFix Result:")
 		for _, currentToken := range result {
 			log.Debugf("> %v", currentToken.toString())

pkg/yqlib/file_utils.go

@@ -7,7 +7,15 @@ import (
 )
 
 func tryRenameFile(from string, to string) error {
-	if renameError := os.Rename(from, to); renameError != nil {
+	if info, err := os.Lstat(to); err == nil && info.Mode()&os.ModeSymlink != 0 {
+		log.Debug("Target file is symlink, skipping rename and attempting to copy contents")
+
+		if copyError := copyFileContents(from, to); copyError != nil {
+			return fmt.Errorf("failed copying from %v to %v: %w", from, to, copyError)
+		}
+		tryRemoveTempFile(from)
+		return nil
+	} else if renameError := os.Rename(from, to); renameError != nil {
 		log.Debugf("Error renaming from %v to %v, attempting to copy contents", from, to)
 		log.Debug(renameError.Error())
 		log.Debug("going to try copying instead")
@@ -22,7 +30,7 @@ func tryRenameFile(from string, to string) error {
 }
 
 func tryRemoveTempFile(filename string) {
-	log.Debug("Removing temp file: %v", filename)
+	log.Debugf("Removing temp file: %v", filename)
 	removeErr := os.Remove(filename)
 	if removeErr != nil {
 		log.Errorf("Failed to remove temp file: %v", filename)
@@ -60,8 +68,7 @@ func SafelyCloseReader(reader io.Reader) {
 func safelyCloseFile(file *os.File) {
 	err := file.Close()
 	if err != nil {
-		log.Error("Error closing file!")
-		log.Error(err.Error())
+		log.Errorf("Error closing file %v: %v", file.Name(), err)
 	}
 }
 

pkg/yqlib/format.go

@@ -22,6 +22,12 @@ var YamlFormat = &Format{"yaml", []string{"y", "yml"},
 	func() Decoder { return NewYamlDecoder(ConfiguredYamlPreferences) },
 }
 
+var KYamlFormat = &Format{"kyaml", []string{"ky"},
+	func() Encoder { return NewKYamlEncoder(ConfiguredKYamlPreferences) },
+	// KYaml is stricter YAML
+	func() Decoder { return NewYamlDecoder(ConfiguredYamlPreferences) },
+}
+
 var JSONFormat = &Format{"json", []string{"j"},
 	func() Encoder { return NewJSONEncoder(ConfiguredJSONPreferences) },
 	func() Decoder { return NewJSONDecoder() },
@@ -63,10 +69,15 @@ var ShFormat = &Format{"", nil,
 }
 
 var TomlFormat = &Format{"toml", []string{},
-	func() Encoder { return NewTomlEncoder() },
+	func() Encoder { return NewTomlEncoderWithPrefs(ConfiguredTomlPreferences) },
 	func() Decoder { return NewTomlDecoder() },
 }
 
+var HclFormat = &Format{"hcl", []string{"h", "tf"},
+	func() Encoder { return NewHclEncoder(ConfiguredHclPreferences) },
+	func() Decoder { return NewHclDecoder() },
+}
+
 var ShellVariablesFormat = &Format{"shell", []string{"s", "sh"},
 	func() Encoder { return NewShellVariablesEncoder() },
 	nil,
@@ -84,6 +95,7 @@ var INIFormat = &Format{"ini", []string{"i"},
 
 var Formats = []*Format{
 	YamlFormat,
+	KYamlFormat,
 	JSONFormat,
 	PropertiesFormat,
 	CSVFormat,
@@ -93,6 +105,7 @@ var Formats = []*Format{
 	UriFormat,
 	ShFormat,
 	TomlFormat,
+	HclFormat,
 	ShellVariablesFormat,
 	LuaFormat,
 	INIFormat,

pkg/yqlib/front_matter.go

@@ -58,7 +58,7 @@ func (f *frontMatterHandlerImpl) Split() error {
 		return err
 	}
 	f.yamlFrontMatterFilename = yamlTempFile.Name()
-	log.Debug("yamlTempFile: %v", yamlTempFile.Name())
+	log.Debugf("yamlTempFile: %v", yamlTempFile.Name())
 
 	lineCount := 0
 

pkg/yqlib/front_matter_test.go

@@ -108,6 +108,55 @@ yaml: doc
 	fmHandler.CleanUp()
 }
 
+func TestFrontMatterFilenamePreserved(t *testing.T) {
+	// Regression test for https://github.com/mikefarah/yq/issues/2538
+	// When using --front-matter, the filename operator should return
+	// the original filename, not the path to the temporary file.
+	file := createTestFile(`---
+name: john
+---
+Some content
+`)
+	originalFilename := "/path/to/original/file.md"
+
+	fmHandler := NewFrontMatterHandler(file)
+	err := fmHandler.Split()
+	if err != nil {
+		panic(err)
+	}
+
+	tempFilename := fmHandler.GetYamlFrontMatterFilename()
+
+	// Register the alias (as the command code does)
+	SetFilenameAlias(tempFilename, originalFilename)
+	defer ClearFilenameAliases()
+
+	// Verify resolveFilename returns the original name
+	resolved := resolveFilename(tempFilename)
+	test.AssertResult(t, originalFilename, resolved)
+
+	// Read documents using the temp file, verify they get the original filename
+	reader, err := readStream(tempFilename)
+	if err != nil {
+		panic(err)
+	}
+	decoder := NewYamlDecoder(ConfiguredYamlPreferences)
+	docs, err := readDocuments(reader, tempFilename, 0, decoder)
+	if err != nil {
+		panic(err)
+	}
+
+	if docs.Len() == 0 {
+		t.Fatal("expected at least one document")
+	}
+
+	firstDoc := docs.Front().Value.(*CandidateNode)
+	test.AssertResult(t, originalFilename, firstDoc.filename)
+
+	tryRemoveTempFile(file)
+	fmHandler.CleanUp()
+}
+
 func TestFrontMatterSplitWithArray(t *testing.T) {
 	file := createTestFile(`[1,2,3]
 ---

pkg/yqlib/hcl.go

@@ -0,0 +1,15 @@
+package yqlib
+
+type HclPreferences struct {
+	ColorsEnabled bool
+}
+
+func NewDefaultHclPreferences() HclPreferences {
+	return HclPreferences{ColorsEnabled: false}
+}
+
+func (p *HclPreferences) Copy() HclPreferences {
+	return HclPreferences{ColorsEnabled: p.ColorsEnabled}
+}
+
+var ConfiguredHclPreferences = NewDefaultHclPreferences()

pkg/yqlib/hcl_test.go

@@ -0,0 +1,585 @@
+//go:build !yq_nohcl
+
+package yqlib
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var nestedExample = `service "http" "web_proxy" {
+  listen_addr = "127.0.0.1:8080"
+}`
+
+var nestedExampleYaml = "service:\n  http:\n    web_proxy:\n      listen_addr: \"127.0.0.1:8080\"\n"
+
+var multipleBlockLabelKeys = `service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+`
+var multipleBlockLabelKeysExpected = `service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server"]
+  }
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+`
+
+var multipleBlockLabelKeysExpectedUpdate = `service "cat" {
+  process "main" {
+    command = ["/usr/local/bin/awesome-app", "server", "meow"]
+  }
+  process "management" {
+    command = ["/usr/local/bin/awesome-app", "management"]
+  }
+}
+`
+
+var multipleBlockLabelKeysExpectedYaml = `service:
+  cat:
+    process:
+      main:
+        command:
+          - "/usr/local/bin/awesome-app"
+          - "server"
+      management:
+        command:
+          - "/usr/local/bin/awesome-app"
+          - "management"
+`
+
+var simpleSample = `# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+
+# String interpolation and templates
+message = "Hello, ${name}!"
+
+# Application-provided functions
+shouty_message = upper(message)`
+
+var simpleSampleExpected = `# Arithmetic with literals and application-provided variables
+sum = 1 + addend
+# String interpolation and templates
+message = "Hello, ${name}!"
+# Application-provided functions
+shouty_message = upper(message)
+`
+
+var simpleSampleExpectedYaml = `# Arithmetic with literals and application-provided variables
+sum: 1 + addend
+# String interpolation and templates
+message: "Hello, ${name}!"
+# Application-provided functions
+shouty_message: upper(message)
+`
+
+var hclFormatScenarios = []formatScenario{
+	{
+		description:  "Parse HCL",
+		input:        `io_mode = "async"`,
+		expected:     "io_mode: \"async\"\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "Simple decode, no quotes",
+		skipDoc:      true,
+		input:        `io_mode = async`,
+		expected:     "io_mode: async\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "Simple roundtrip, no quotes",
+		skipDoc:      true,
+		input:        `io_mode = async`,
+		expected:     "io_mode = async\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Nested decode",
+		skipDoc:      true,
+		input:        nestedExample,
+		expected:     nestedExampleYaml,
+		scenarioType: "decode",
+	},
+	{
+		description:  "Template decode",
+		skipDoc:      true,
+		input:        `message = "Hello, ${name}!"`,
+		expected:     "message: \"Hello, ${name}!\"\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "Roundtrip: with template",
+		skipDoc:      true,
+		input:        `message = "Hello, ${name}!"`,
+		expected:     "message = \"Hello, ${name}!\"\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip: with function",
+		skipDoc:      true,
+		input:        `shouty_message = upper(message)`,
+		expected:     "shouty_message = upper(message)\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip: with arithmetic",
+		skipDoc:      true,
+		input:        `sum = 1 + addend`,
+		expected:     "sum = 1 + addend\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Arithmetic decode",
+		skipDoc:      true,
+		input:        `sum = 1 + addend`,
+		expected:     "sum: 1 + addend\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "number attribute",
+		skipDoc:      true,
+		input:        `port = 8080`,
+		expected:     "port: 8080\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "float attribute",
+		skipDoc:      true,
+		input:        `pi = 3.14`,
+		expected:     "pi: 3.14\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "boolean attribute",
+		skipDoc:      true,
+		input:        `enabled = true`,
+		expected:     "enabled: true\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "object/map attribute",
+		skipDoc:      true,
+		input:        `obj = { a = 1, b = "two" }`,
+		expected:     "obj: {a: 1, b: \"two\"}\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "nested block",
+		skipDoc:      true,
+		input:        `server { port = 8080 }`,
+		expected:     "server:\n  port: 8080\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "multiple attributes",
+		skipDoc:      true,
+		input:        "name = \"app\"\nversion = 1\nenabled = true",
+		expected:     "name: \"app\"\nversion: 1\nenabled: true\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "binary expression",
+		skipDoc:      true,
+		input:        `count = 0 - 42`,
+		expected:     "count: -42\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "negative number",
+		skipDoc:      true,
+		input:        `count = -42`,
+		expected:     "count: -42\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "scientific notation",
+		skipDoc:      true,
+		input:        `value = 1e-3`,
+		expected:     "value: 0.001\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "nested object",
+		skipDoc:      true,
+		input:        `config = { db = { host = "localhost", port = 5432 } }`,
+		expected:     "config: {db: {host: \"localhost\", port: 5432}}\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "mixed list",
+		skipDoc:      true,
+		input:        `values = [1, "two", true]`,
+		expected:     "values:\n  - 1\n  - \"two\"\n  - true\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "Roundtrip: Sample Doc",
+		input:        multipleBlockLabelKeys,
+		expected:     multipleBlockLabelKeysExpected,
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip: With an update",
+		input:        multipleBlockLabelKeys,
+		expression:   `.service.cat.process.main.command += "meow"`,
+		expected:     multipleBlockLabelKeysExpectedUpdate,
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Parse HCL: Sample Doc",
+		input:        multipleBlockLabelKeys,
+		expected:     multipleBlockLabelKeysExpectedYaml,
+		scenarioType: "decode",
+	},
+	{
+		description:  "block with labels",
+		skipDoc:      true,
+		input:        `resource "aws_instance" "example" { ami = "ami-12345" }`,
+		expected:     "resource:\n  aws_instance:\n    example:\n      ami: \"ami-12345\"\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "block with labels roundtrip",
+		skipDoc:      true,
+		input:        `resource "aws_instance" "example" { ami = "ami-12345" }`,
+		expected:     "resource \"aws_instance\" \"example\" {\n  ami = \"ami-12345\"\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip simple attribute",
+		skipDoc:      true,
+		input:        `io_mode = "async"`,
+		expected:     `io_mode = "async"` + "\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip number attribute",
+		skipDoc:      true,
+		input:        `port = 8080`,
+		expected:     "port = 8080\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip float attribute",
+		skipDoc:      true,
+		input:        `pi = 3.14`,
+		expected:     "pi = 3.14\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip boolean attribute",
+		skipDoc:      true,
+		input:        `enabled = true`,
+		expected:     "enabled = true\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip list of strings",
+		skipDoc:      true,
+		input:        `tags = ["a", "b"]`,
+		expected:     "tags = [\"a\", \"b\"]\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip object/map attribute",
+		skipDoc:      true,
+		input:        `obj = { a = 1, b = "two" }`,
+		expected:     "obj = {\n  a = 1\n  b = \"two\"\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip nested block",
+		skipDoc:      true,
+		input:        `server { port = 8080 }`,
+		expected:     "server {\n  port = 8080\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip multiple attributes",
+		skipDoc:      true,
+		input:        "name = \"app\"\nversion = 1\nenabled = true",
+		expected:     "name = \"app\"\nversion = 1\nenabled = true\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Parse HCL: with comments",
+		input:        "# Configuration\nport = 8080 # server port",
+		expected:     "# Configuration\nport: 8080 # server port\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "Roundtrip: with comments",
+		input:        "# Configuration\nport = 8080",
+		expected:     "# Configuration\nport = 8080\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip:  extraction",
+		skipDoc:      true,
+		input:        simpleSample,
+		expression:   ".shouty_message",
+		expected:     "upper(message)\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip: With templates, functions and arithmetic",
+		input:        simpleSample,
+		expected:     simpleSampleExpected,
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip example",
+		skipDoc:      true,
+		input:        simpleSample,
+		expected:     simpleSampleExpectedYaml,
+		scenarioType: "decode",
+	},
+	{
+		description:  "Parse HCL: List of strings",
+		skipDoc:      true,
+		input:        `tags = ["a", "b"]`,
+		expected:     "tags:\n  - \"a\"\n  - \"b\"\n",
+		scenarioType: "decode",
+	},
+	{
+		description:  "roundtrip list of objects",
+		skipDoc:      true,
+		input:        `items = [{ name = "a", value = 1 }, { name = "b", value = 2 }]`,
+		expected:     "items = [{\n  name = \"a\"\n  value = 1\n  }, {\n  name = \"b\"\n  value = 2\n}]\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip nested blocks with same name",
+		skipDoc:      true,
+		input:        "database \"primary\" {\n  host = \"localhost\"\n  port = 5432\n}\ndatabase \"replica\" {\n  host = \"replica.local\"\n  port = 5433\n}",
+		expected:     "database \"primary\" {\n  host = \"localhost\"\n  port = 5432\n}\ndatabase \"replica\" {\n  host = \"replica.local\"\n  port = 5433\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip mixed nested structure",
+		skipDoc:      true,
+		input:        "servers \"web\" {\n  addresses = [\"10.0.1.1\", \"10.0.1.2\"]\n  port = 8080\n}",
+		expected:     "servers \"web\" {\n  addresses = [\"10.0.1.1\", \"10.0.1.2\"]\n  port = 8080\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip null value",
+		skipDoc:      true,
+		input:        `value = null`,
+		expected:     "value = null\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip empty list",
+		skipDoc:      true,
+		input:        `items = []`,
+		expected:     "items = []\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip empty object",
+		skipDoc:      true,
+		input:        `config = {}`,
+		expected:     "config = {}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Roundtrip: Separate blocks with same name.",
+		input:        "resource \"aws_instance\" \"web\" {\n  ami = \"ami-12345\"\n}\nresource \"aws_instance\" \"db\" {\n  ami = \"ami-67890\"\n}",
+		expected:     "resource \"aws_instance\" \"web\" {\n  ami = \"ami-12345\"\n}\nresource \"aws_instance\" \"db\" {\n  ami = \"ami-67890\"\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip deeply nested structure",
+		skipDoc:      true,
+		input:        "app \"database\" \"primary\" \"connection\" {\n  host = \"db.local\"\n  port = 5432\n}",
+		expected:     "app \"database\" \"primary\" \"connection\" {\n  host = \"db.local\"\n  port = 5432\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "roundtrip with leading comments",
+		skipDoc:      true,
+		input:        "# Main config\nenabled = true\nport = 8080",
+		expected:     "# Main config\nenabled = true\nport = 8080\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Multiple attributes with comments (comment safety with safe path separator)",
+		skipDoc:      true,
+		input:        "# Database config\ndb_host = \"localhost\"\n# Connection pool\ndb_pool = 10",
+		expected:     "# Database config\ndb_host = \"localhost\"\n# Connection pool\ndb_pool = 10\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Nested blocks with head comments",
+		skipDoc:      true,
+		input:        "service \"api\" {\n  # Listen address\n  listen = \"0.0.0.0:8080\"\n  # TLS enabled\n  tls = true\n}",
+		expected:     "service \"api\" {\n  # Listen address\n  listen = \"0.0.0.0:8080\"\n  # TLS enabled\n  tls = true\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Multiple blocks with EncodeSeparate preservation",
+		skipDoc:      true,
+		input:        "resource \"aws_s3_bucket\" \"bucket1\" {\n  bucket = \"my-bucket-1\"\n}\nresource \"aws_s3_bucket\" \"bucket2\" {\n  bucket = \"my-bucket-2\"\n}",
+		expected:     "resource \"aws_s3_bucket\" \"bucket1\" {\n  bucket = \"my-bucket-1\"\n}\nresource \"aws_s3_bucket\" \"bucket2\" {\n  bucket = \"my-bucket-2\"\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Blocks with same name handled separately",
+		skipDoc:      true,
+		input:        "server \"primary\" { port = 8080 }\nserver \"backup\" { port = 8081 }",
+		expected:     "server \"primary\" {\n  port = 8080\n}\nserver \"backup\" {\n  port = 8081\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Block label with dot roundtrip (commentPathSep)",
+		skipDoc:      true,
+		input:        "service \"api.service\" {\n  port = 8080\n}",
+		expected:     "service \"api.service\" {\n  port = 8080\n}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Nested template expression",
+		skipDoc:      true,
+		input:        `message = "User: ${username}, Role: ${user_role}"`,
+		expected:     "message = \"User: ${username}, Role: ${user_role}\"\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Empty object roundtrip",
+		skipDoc:      true,
+		input:        `obj = {}`,
+		expected:     "obj = {}\n",
+		scenarioType: "roundtrip",
+	},
+	{
+		description:  "Null value in block",
+		skipDoc:      true,
+		input:        `service { optional_field = null }`,
+		expected:     "service {\n  optional_field = null\n}\n",
+		scenarioType: "roundtrip",
+	},
+}
+
+func testHclScenario(t *testing.T, s formatScenario) {
+	switch s.scenarioType {
+	case "decode":
+		result := mustProcessFormatScenario(s, NewHclDecoder(), NewYamlEncoder(ConfiguredYamlPreferences))
+		test.AssertResultWithContext(t, s.expected, result, s.description)
+	case "roundtrip":
+		test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewHclDecoder(), NewHclEncoder(ConfiguredHclPreferences)), s.description)
+	}
+}
+
+func documentHclScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
+	s := i.(formatScenario)
+
+	if s.skipDoc {
+		return
+	}
+	switch s.scenarioType {
+	case "", "decode":
+		documentHclDecodeScenario(w, s)
+	case "roundtrip":
+		documentHclRoundTripScenario(w, s)
+	default:
+		panic(fmt.Sprintf("unhandled scenario type %q", s.scenarioType))
+	}
+}
+
+func documentHclDecodeScenario(w *bufio.Writer, s formatScenario) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, "Given a sample.hcl file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```hcl\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+	expression := s.expression
+	if s.expression != "" {
+		expression = fmt.Sprintf(" '%v'", s.expression)
+	}
+	writeOrPanic(w, fmt.Sprintf("```bash\nyq -oy%v sample.hcl\n```\n", expression))
+	writeOrPanic(w, "will output\n")
+
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewHclDecoder(), NewYamlEncoder(ConfiguredYamlPreferences))))
+}
+
+func documentHclRoundTripScenario(w *bufio.Writer, s formatScenario) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, "Given a sample.hcl file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```hcl\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+	expression := s.expression
+	if s.expression != "" {
+		expression = fmt.Sprintf(" '%v'", s.expression)
+	}
+	writeOrPanic(w, fmt.Sprintf("```bash\nyq%v sample.hcl\n```\n", expression))
+	writeOrPanic(w, "will output\n")
+
+	writeOrPanic(w, fmt.Sprintf("```hcl\n%v```\n\n", mustProcessFormatScenario(s, NewHclDecoder(), NewHclEncoder(ConfiguredHclPreferences))))
+}
+
+func TestHclEncoderPrintDocumentSeparator(t *testing.T) {
+	encoder := NewHclEncoder(ConfiguredHclPreferences)
+	var buf bytes.Buffer
+	writer := bufio.NewWriter(&buf)
+
+	err := encoder.PrintDocumentSeparator(writer)
+	writer.Flush()
+
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "", buf.String())
+}
+
+func TestHclEncoderPrintLeadingContent(t *testing.T) {
+	encoder := NewHclEncoder(ConfiguredHclPreferences)
+	var buf bytes.Buffer
+	writer := bufio.NewWriter(&buf)
+
+	err := encoder.PrintLeadingContent(writer, "some content")
+	writer.Flush()
+
+	test.AssertResult(t, nil, err)
+	test.AssertResult(t, "", buf.String())
+}
+
+func TestHclEncoderCanHandleAliases(t *testing.T) {
+	encoder := NewHclEncoder(ConfiguredHclPreferences)
+	test.AssertResult(t, false, encoder.CanHandleAliases())
+}
+
+func TestHclFormatScenarios(t *testing.T) {
+	for _, tt := range hclFormatScenarios {
+		testHclScenario(t, tt)
+	}
+	genericScenarios := make([]interface{}, len(hclFormatScenarios))
+	for i, s := range hclFormatScenarios {
+		genericScenarios[i] = s
+	}
+	documentScenarios(t, "usage", "hcl", genericScenarios, documentHclScenario)
+}

pkg/yqlib/kyaml.go

@@ -0,0 +1,30 @@
+//go:build !yq_nokyaml
+
+package yqlib
+
+type KYamlPreferences struct {
+	Indent             int
+	ColorsEnabled      bool
+	PrintDocSeparators bool
+	UnwrapScalar       bool
+}
+
+func NewDefaultKYamlPreferences() KYamlPreferences {
+	return KYamlPreferences{
+		Indent:             2,
+		ColorsEnabled:      false,
+		PrintDocSeparators: true,
+		UnwrapScalar:       true,
+	}
+}
+
+func (p *KYamlPreferences) Copy() KYamlPreferences {
+	return KYamlPreferences{
+		Indent:             p.Indent,
+		ColorsEnabled:      p.ColorsEnabled,
+		PrintDocSeparators: p.PrintDocSeparators,
+		UnwrapScalar:       p.UnwrapScalar,
+	}
+}
+
+var ConfiguredKYamlPreferences = NewDefaultKYamlPreferences()

pkg/yqlib/kyaml_test.go

@@ -0,0 +1,542 @@
+//go:build !yq_nokyaml
+
+package yqlib
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var ansiRe = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+
+func stripANSI(s string) string {
+	return ansiRe.ReplaceAllString(s, "")
+}
+
+var kyamlFormatScenarios = []formatScenario{
+	{
+		description:    "Encode kyaml: plain string scalar",
+		subdescription: "Strings are always double-quoted in KYaml output.",
+		scenarioType:   "encode",
+		indent:         2,
+		input:          "cat\n",
+		expected:       "\"cat\"\n",
+	},
+	{
+		description:  "encode plain int scalar",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "12\n",
+		expected:     "12\n",
+		skipDoc:      true,
+	},
+	{
+		description:  "encode plain bool scalar",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "true\n",
+		expected:     "true\n",
+		skipDoc:      true,
+	},
+	{
+		description:  "encode plain null scalar",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "null\n",
+		expected:     "null\n",
+		skipDoc:      true,
+	},
+	{
+		description:  "encode flow mapping and sequence",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "a: b\nc:\n  - d\n",
+		expected: "{\n" +
+			"  a: \"b\",\n" +
+			"  c: [\n" +
+			"    \"d\",\n" +
+			"  ],\n" +
+			"}\n",
+	},
+	{
+		description:  "encode non-string scalars",
+		scenarioType: "encode",
+		indent:       2,
+		input: "a: 12\n" +
+			"b: true\n" +
+			"c: null\n" +
+			"d: \"true\"\n",
+		expected: "{\n" +
+			"  a: 12,\n" +
+			"  b: true,\n" +
+			"  c: null,\n" +
+			"  d: \"true\",\n" +
+			"}\n",
+	},
+	{
+		description:  "quote non-identifier keys",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "\"1a\": b\n\"has space\": c\n",
+		expected: "{\n" +
+			"  \"1a\": \"b\",\n" +
+			"  \"has space\": \"c\",\n" +
+			"}\n",
+	},
+	{
+		description:  "escape quoted strings",
+		scenarioType: "encode",
+		indent:       2,
+		input:        "a: \"line1\\nline2\\t\\\"q\\\"\"\n",
+		expected: "{\n" +
+			"  a: \"line1\\nline2\\t\\\"q\\\"\",\n" +
+			"}\n",
+	},
+	{
+		description:  "preserve comments when encoding",
+		scenarioType: "encode",
+		indent:       2,
+		input: "# leading\n" +
+			"a: 1 # a line\n" +
+			"# head b\n" +
+			"b: 2\n" +
+			"c:\n" +
+			"  # head d\n" +
+			"  - d # d line\n" +
+			"  - e\n" +
+			"# trailing\n",
+		expected: "# leading\n" +
+			"{\n" +
+			"  a: 1, # a line\n" +
+			"  # head b\n" +
+			"  b: 2,\n" +
+			"  c: [\n" +
+			"    # head d\n" +
+			"    \"d\", # d line\n" +
+			"    \"e\",\n" +
+			"  ],\n" +
+			"  # trailing\n" +
+			"}\n",
+	},
+	{
+		description:    "Encode kyaml: anchors and aliases",
+		subdescription: "KYaml output does not support anchors/aliases; they are expanded to concrete values.",
+		scenarioType:   "encode",
+		indent:         2,
+		input: "base: &base\n" +
+			"  a: b\n" +
+			"copy: *base\n",
+		expected: "{\n" +
+			"  base: {\n" +
+			"    a: \"b\",\n" +
+			"  },\n" +
+			"  copy: {\n" +
+			"    a: \"b\",\n" +
+			"  },\n" +
+			"}\n",
+	},
+	{
+		description:    "Encode kyaml: yaml to kyaml shows formatting differences",
+		subdescription: "KYaml uses flow-style collections (braces/brackets) and explicit commas.",
+		scenarioType:   "encode",
+		indent:         2,
+		input: "person:\n" +
+			"  name: John\n" +
+			"  pets:\n" +
+			"    - cat\n" +
+			"    - dog\n",
+		expected: "{\n" +
+			"  person: {\n" +
+			"    name: \"John\",\n" +
+			"    pets: [\n" +
+			"      \"cat\",\n" +
+			"      \"dog\",\n" +
+			"    ],\n" +
+			"  },\n" +
+			"}\n",
+	},
+	{
+		description:    "Encode kyaml: nested lists of objects",
+		subdescription: "Lists and objects can be nested arbitrarily; KYaml always uses flow-style collections.",
+		scenarioType:   "encode",
+		indent:         2,
+		input: "- name: a\n" +
+			"  items:\n" +
+			"    - id: 1\n" +
+			"      tags:\n" +
+			"        - k: x\n" +
+			"          v: y\n" +
+			"        - k: x2\n" +
+			"          v: y2\n" +
+			"    - id: 2\n" +
+			"      tags:\n" +
+			"        - k: z\n" +
+			"          v: w\n",
+		expected: "[\n" +
+			"  {\n" +
+			"    name: \"a\",\n" +
+			"    items: [\n" +
+			"      {\n" +
+			"        id: 1,\n" +
+			"        tags: [\n" +
+			"          {\n" +
+			"            k: \"x\",\n" +
+			"            v: \"y\",\n" +
+			"          },\n" +
+			"          {\n" +
+			"            k: \"x2\",\n" +
+			"            v: \"y2\",\n" +
+			"          },\n" +
+			"        ],\n" +
+			"      },\n" +
+			"      {\n" +
+			"        id: 2,\n" +
+			"        tags: [\n" +
+			"          {\n" +
+			"            k: \"z\",\n" +
+			"            v: \"w\",\n" +
+			"          },\n" +
+			"        ],\n" +
+			"      },\n" +
+			"    ],\n" +
+			"  },\n" +
+			"]\n",
+	},
+}
+
+func testKYamlScenario(t *testing.T, s formatScenario) {
+	prefs := ConfiguredKYamlPreferences.Copy()
+	prefs.Indent = s.indent
+	prefs.UnwrapScalar = false
+
+	switch s.scenarioType {
+	case "encode":
+		test.AssertResultWithContext(
+			t,
+			s.expected,
+			mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewKYamlEncoder(prefs)),
+			s.description,
+		)
+	default:
+		panic(fmt.Sprintf("unhandled scenario type %q", s.scenarioType))
+	}
+}
+
+func documentKYamlScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
+	s := i.(formatScenario)
+	if s.skipDoc {
+		return
+	}
+
+	switch s.scenarioType {
+	case "encode":
+		documentKYamlEncodeScenario(w, s)
+	default:
+		panic(fmt.Sprintf("unhandled scenario type %q", s.scenarioType))
+	}
+}
+
+func documentKYamlEncodeScenario(w *bufio.Writer, s formatScenario) {
+	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
+	if s.subdescription != "" {
+		writeOrPanic(w, s.subdescription)
+		writeOrPanic(w, "\n\n")
+	}
+
+	writeOrPanic(w, "Given a sample.yml file of:\n")
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v\n```\n", s.input))
+
+	writeOrPanic(w, "then\n")
+
+	expression := s.expression
+	if expression == "" {
+		expression = "."
+	}
+
+	if s.indent == 2 {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=kyaml '%v' sample.yml\n```\n", expression))
+	} else {
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq -o=kyaml -I=%v '%v' sample.yml\n```\n", s.indent, expression))
+	}
+
+	writeOrPanic(w, "will output\n")
+
+	prefs := ConfiguredKYamlPreferences.Copy()
+	prefs.Indent = s.indent
+	prefs.UnwrapScalar = false
+
+	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewKYamlEncoder(prefs))))
+}
+
+func TestKYamlFormatScenarios(t *testing.T) {
+	for _, s := range kyamlFormatScenarios {
+		testKYamlScenario(t, s)
+	}
+
+	genericScenarios := make([]interface{}, len(kyamlFormatScenarios))
+	for i, s := range kyamlFormatScenarios {
+		genericScenarios[i] = s
+	}
+	documentScenarios(t, "usage", "kyaml", genericScenarios, documentKYamlScenario)
+}
+
+func TestKYamlEncoderPrintDocumentSeparator(t *testing.T) {
+	t.Run("enabled", func(t *testing.T) {
+		prefs := NewDefaultKYamlPreferences()
+		prefs.PrintDocSeparators = true
+
+		var buf bytes.Buffer
+		err := NewKYamlEncoder(prefs).PrintDocumentSeparator(&buf)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "---\n" {
+			t.Fatalf("expected doc separator, got %q", buf.String())
+		}
+	})
+
+	t.Run("disabled", func(t *testing.T) {
+		prefs := NewDefaultKYamlPreferences()
+		prefs.PrintDocSeparators = false
+
+		var buf bytes.Buffer
+		err := NewKYamlEncoder(prefs).PrintDocumentSeparator(&buf)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "" {
+			t.Fatalf("expected no output, got %q", buf.String())
+		}
+	})
+}
+
+func TestKYamlEncoderEncodeUnwrapScalar(t *testing.T) {
+	prefs := NewDefaultKYamlPreferences()
+	prefs.UnwrapScalar = true
+
+	var buf bytes.Buffer
+	err := NewKYamlEncoder(prefs).Encode(&buf, &CandidateNode{
+		Kind:  ScalarNode,
+		Tag:   "!!str",
+		Value: "cat",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if buf.String() != "cat\n" {
+		t.Fatalf("expected unwrapped scalar, got %q", buf.String())
+	}
+}
+
+func TestKYamlEncoderEncodeColorsEnabled(t *testing.T) {
+	prefs := NewDefaultKYamlPreferences()
+	prefs.UnwrapScalar = false
+	prefs.ColorsEnabled = true
+
+	var buf bytes.Buffer
+	err := NewKYamlEncoder(prefs).Encode(&buf, &CandidateNode{
+		Kind: MappingNode,
+		Content: []*CandidateNode{
+			{Kind: ScalarNode, Tag: "!!str", Value: "a"},
+			{Kind: ScalarNode, Tag: "!!str", Value: "b"},
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	out := stripANSI(buf.String())
+	if !strings.Contains(out, "a:") || !strings.Contains(out, "\"b\"") {
+		t.Fatalf("expected colourised output to contain rendered tokens, got %q", out)
+	}
+}
+
+func TestKYamlEncoderWriteNodeAliasAndUnknown(t *testing.T) {
+	ke := NewKYamlEncoder(NewDefaultKYamlPreferences()).(*kyamlEncoder)
+
+	t.Run("alias_nil", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{Kind: AliasNode}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "null" {
+			t.Fatalf("expected null for nil alias, got %q", buf.String())
+		}
+	})
+
+	t.Run("alias_value", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{
+			Kind:  AliasNode,
+			Alias: &CandidateNode{Kind: ScalarNode, Tag: "!!int", Value: "12"},
+		}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "12" {
+			t.Fatalf("expected dereferenced alias value, got %q", buf.String())
+		}
+	})
+
+	t.Run("unknown_kind", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{Kind: Kind(12345)}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "null" {
+			t.Fatalf("expected null for unknown kind, got %q", buf.String())
+		}
+	})
+}
+
+func TestKYamlEncoderEmptyCollections(t *testing.T) {
+	ke := NewKYamlEncoder(NewDefaultKYamlPreferences()).(*kyamlEncoder)
+
+	t.Run("empty_mapping", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{Kind: MappingNode}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "{}" {
+			t.Fatalf("expected empty mapping, got %q", buf.String())
+		}
+	})
+
+	t.Run("empty_sequence", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{Kind: SequenceNode}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "[]" {
+			t.Fatalf("expected empty sequence, got %q", buf.String())
+		}
+	})
+}
+
+func TestKYamlEncoderScalarFallbackAndEscaping(t *testing.T) {
+	ke := NewKYamlEncoder(NewDefaultKYamlPreferences()).(*kyamlEncoder)
+
+	t.Run("unknown_tag_falls_back_to_string", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeNode(&buf, &CandidateNode{Kind: ScalarNode, Tag: "!!timestamp", Value: "2020-01-01T00:00:00Z"}, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != "\"2020-01-01T00:00:00Z\"" {
+			t.Fatalf("expected quoted fallback, got %q", buf.String())
+		}
+	})
+
+	t.Run("escape_double_quoted", func(t *testing.T) {
+		got := escapeDoubleQuotedString("a\\b\"c\n\r\t" + string(rune(0x01)))
+		want := "a\\\\b\\\"c\\n\\r\\t\\u0001"
+		if got != want {
+			t.Fatalf("expected %q, got %q", want, got)
+		}
+	})
+
+	t.Run("valid_bare_key", func(t *testing.T) {
+		if isValidKYamlBareKey("") {
+			t.Fatalf("expected empty string to be invalid")
+		}
+		if isValidKYamlBareKey("1a") {
+			t.Fatalf("expected leading digit to be invalid")
+		}
+		if !isValidKYamlBareKey("a_b-2") {
+			t.Fatalf("expected identifier-like key to be valid")
+		}
+	})
+}
+
+func TestKYamlEncoderCommentsInMapping(t *testing.T) {
+	prefs := NewDefaultKYamlPreferences()
+	prefs.UnwrapScalar = false
+	ke := NewKYamlEncoder(prefs).(*kyamlEncoder)
+
+	var buf bytes.Buffer
+	err := ke.writeNode(&buf, &CandidateNode{
+		Kind: MappingNode,
+		Content: []*CandidateNode{
+			{
+				Kind:        ScalarNode,
+				Tag:         "!!str",
+				Value:       "a",
+				HeadComment: "key head",
+				LineComment: "key line",
+				FootComment: "key foot",
+			},
+			{
+				Kind:        ScalarNode,
+				Tag:         "!!str",
+				Value:       "b",
+				HeadComment: "value head",
+			},
+		},
+	}, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	out := buf.String()
+	if !strings.Contains(out, "# key head\n") {
+		t.Fatalf("expected key head comment, got %q", out)
+	}
+	if !strings.Contains(out, "# value head\n") {
+		t.Fatalf("expected value head comment, got %q", out)
+	}
+	if !strings.Contains(out, ", # key line\n") {
+		t.Fatalf("expected inline key comment fallback, got %q", out)
+	}
+	if !strings.Contains(out, "# key foot\n") {
+		t.Fatalf("expected foot comment fallback, got %q", out)
+	}
+}
+
+func TestKYamlEncoderCommentBlockAndInlineComment(t *testing.T) {
+	ke := NewKYamlEncoder(NewDefaultKYamlPreferences()).(*kyamlEncoder)
+
+	t.Run("comment_block_prefixing_and_crlf", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeCommentBlock(&buf, "line1\r\n\r\n# already\r\nline2", 2)
+		if err != nil {
+			t.Fatal(err)
+		}
+		want := "  # line1\n  # already\n  # line2\n"
+		if buf.String() != want {
+			t.Fatalf("expected %q, got %q", want, buf.String())
+		}
+	})
+
+	t.Run("inline_comment_prefix_and_first_line_only", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeInlineComment(&buf, "hello\r\nsecond line")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != " # hello" {
+			t.Fatalf("expected %q, got %q", " # hello", buf.String())
+		}
+	})
+
+	t.Run("inline_comment_already_prefixed", func(t *testing.T) {
+		var buf bytes.Buffer
+		err := ke.writeInlineComment(&buf, "# hello")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if buf.String() != " # hello" {
+			t.Fatalf("expected %q, got %q", " # hello", buf.String())
+		}
+	})
+}

pkg/yqlib/lexer.go

@@ -61,7 +61,7 @@ func unwrap(value string) string {
 }
 
 func extractNumberParameter(value string) (int, error) {
-	parameterParser := regexp.MustCompile(`.*\(([0-9]+)\)`)
+	parameterParser := regexp.MustCompile(`.*\((-?[0-9]+)\)`)
 	matches := parameterParser.FindStringSubmatch(value)
 	var indent, errParsingInt = parseInt(matches[1])
 	if errParsingInt != nil {
@@ -105,7 +105,7 @@ func handleToken(tokens []*token, index int, postProcessedTokens []*token) (toke
 	skipNextToken = false
 	currentToken := tokens[index]
 
-	log.Debug("processing %v", currentToken.toString(true))
+	log.Debugf("processing %v", currentToken.toString(true))
 
 	if currentToken.TokenType == traverseArrayCollect {
 		// `.[exp]`` works by creating a traversal array of [self, exp] and piping that into the traverse array operator
@@ -131,6 +131,11 @@ func handleToken(tokens []*token, index int, postProcessedTokens []*token) (toke
 			log.Debugf("previous token is : traverseArrayOpType")
 			// need to put the number 0 before this token, as that is implied
 			postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: createValueOperation(0, "0")})
+		} else if index >= 2 && tokens[index-1].TokenType == openCollect &&
+			(tokens[index-2].TokenType == operationToken || tokens[index-2].TokenType == closeCollect || tokens[index-2].TokenType == closeCollectObject) {
+			log.Debugf("previous token is : openCollect following a traversal, implying 0 start")
+			// need to put the number 0 before this token, as that is implied
+			postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: createValueOperation(0, "0")})
 		}
 	}
 

pkg/yqlib/lexer_participle.go

@@ -57,7 +57,7 @@ var participleYqRules = []*participleYqRule{
 	simpleOp("sort_?keys", sortKeysOpType),
 
 	{"ArrayToMap", "array_?to_?map", expressionOpToken(`(.[] | select(. != null) ) as $i ireduce({}; .[$i | key] = $i)`), 0},
-
+	{"Root", "root", expressionOpToken(`parent(-1)`), 0},
 	{"YamlEncodeWithIndent", `to_?yaml\([0-9]+\)`, encodeParseIndent(YamlFormat), 0},
 	{"XMLEncodeWithIndent", `to_?xml\([0-9]+\)`, encodeParseIndent(XMLFormat), 0},
 	{"JSONEncodeWithIndent", `to_?json\([0-9]+\)`, encodeParseIndent(JSONFormat), 0},
@@ -96,6 +96,8 @@ var participleYqRules = []*participleYqRule{
 	simpleOp("load_?str|str_?load", loadStringOpType),
 	{"LoadYaml", `load`, loadOp(NewYamlDecoder(LoadYamlPreferences)), 0},
 
+	simpleOp("system", systemOpType),
+
 	{"SplitDocument", `splitDoc|split_?doc`, opToken(splitDocumentOpType), 0},
 
 	simpleOp("select", selectOpType),
@@ -132,7 +134,7 @@ var participleYqRules = []*participleYqRule{
 	simpleOp("split", splitStringOpType),
 
 	simpleOp("parents", getParentsOpType),
-	{"ParentWithLevel", `parent\([0-9]+\)`, parentWithLevel(), 0},
+	{"ParentWithLevel", `parent\(-?[0-9]+\)`, parentWithLevel(), 0},
 	{"ParentWithDefaultLevel", `parent`, parentWithDefaultLevel(), 0},
 
 	simpleOp("keys", keysOpType),
@@ -283,7 +285,7 @@ func pathToken(wrapped bool) yqAction {
 		if wrapped {
 			value = unwrap(value)
 		}
-		log.Debug("PathToken %v", value)
+		log.Debugf("PathToken %v", value)
 		op := &Operation{OperationType: traversePathOpType, Value: value, StringValue: value, Preferences: prefs}
 		return &token{TokenType: operationToken, Operation: op, CheckForPostTraverse: true}, nil
 	}
@@ -336,7 +338,7 @@ func flattenWithDepth() yqAction {
 
 func assignAllCommentsOp(updateAssign bool) yqAction {
 	return func(rawToken lexer.Token) (*token, error) {
-		log.Debug("assignAllCommentsOp %v", rawToken.Value)
+		log.Debugf("assignAllCommentsOp %v", rawToken.Value)
 		value := rawToken.Value
 		op := &Operation{
 			OperationType: assignCommentOpType,
@@ -351,7 +353,7 @@ func assignAllCommentsOp(updateAssign bool) yqAction {
 
 func assignOpToken(updateAssign bool) yqAction {
 	return func(rawToken lexer.Token) (*token, error) {
-		log.Debug("assignOpToken %v", rawToken.Value)
+		log.Debugf("assignOpToken %v", rawToken.Value)
 		value := rawToken.Value
 		prefs := assignPreferences{DontOverWriteAnchor: true}
 		if strings.Contains(value, "c") {
@@ -376,9 +378,9 @@ func nullValue() yqAction {
 
 func stringValue() yqAction {
 	return func(rawToken lexer.Token) (*token, error) {
-		log.Debug("rawTokenvalue: %v", rawToken.Value)
+		log.Debugf("rawTokenvalue: %v", rawToken.Value)
 		value := unwrap(rawToken.Value)
-		log.Debug("unwrapped: %v", value)
+		log.Debugf("unwrapped: %v", value)
 		value = processEscapeCharacters(value)
 		return &token{TokenType: operationToken, Operation: &Operation{
 			OperationType: stringInterpolationOpType,
@@ -451,6 +453,7 @@ func multiplyWithPrefs(op *operationType) yqAction {
 			prefs.AssignPrefs.ClobberCustomTags = true
 		}
 		prefs.TraversePrefs.DontFollowAlias = true
+		prefs.TraversePrefs.ExactKeyMatch = true
 		op := &Operation{OperationType: op, Value: multiplyOpType.Type, StringValue: options, Preferences: prefs}
 		return &token{TokenType: operationToken, Operation: op}, nil
 	}

pkg/yqlib/lib.go

@@ -4,11 +4,10 @@ package yqlib
 import (
 	"container/list"
 	"fmt"
+	"log/slog"
 	"math"
 	"strconv"
 	"strings"
-
-	logging "gopkg.in/op/go-logging.v1"
 )
 
 var ExpressionParser ExpressionParserInterface
@@ -19,17 +18,17 @@ func InitExpressionParser() {
 	}
 }
 
-var log = logging.MustGetLogger("yq-lib")
+var log = newLogger()
 
 var PrettyPrintExp = `(... | (select(tag != "!!str"), select(tag == "!!str") | select(test("(?i)^(y|yes|n|no|on|off)$") | not))  ) style=""`
 
 // GetLogger returns the yq logger instance.
-func GetLogger() *logging.Logger {
+func GetLogger() *Logger {
 	return log
 }
 
 func getContentValueByKey(content []*CandidateNode, key string) *CandidateNode {
-	for index := 0; index < len(content); index = index + 2 {
+	for index := 0; index < len(content)-1; index = index + 2 {
 		keyNode := content[index]
 		valueNode := content[index+1]
 		if keyNode.Value == key {
@@ -81,7 +80,7 @@ func recurseNodeObjectEqual(lhs *CandidateNode, rhs *CandidateNode) bool {
 		key := lhs.Content[index]
 		value := lhs.Content[index+1]
 
-		indexInRHS := findInArray(rhs, key)
+		indexInRHS := findKeyInMap(rhs, key)
 
 		if indexInRHS == -1 || !recursiveNodeEqual(value, rhs.Content[indexInRHS+1]) {
 			return false
@@ -251,7 +250,7 @@ func processEscapeCharacters(original string) string {
 
 	value := result.String()
 	if value != original {
-		log.Debug("processEscapeCharacters from [%v] to [%v]", original, value)
+		log.Debugf("processEscapeCharacters from [%v] to [%v]", original, value)
 	}
 	return value
 }
@@ -274,7 +273,7 @@ func footComment(node *CandidateNode) string {
 
 // use for debugging only
 func NodesToString(collection *list.List) string {
-	if !log.IsEnabledFor(logging.DEBUG) {
+	if !log.IsEnabledFor(slog.LevelDebug) {
 		return ""
 	}
 
@@ -286,7 +285,7 @@ func NodesToString(collection *list.List) string {
 }
 
 func NodeToString(node *CandidateNode) string {
-	if !log.IsEnabledFor(logging.DEBUG) {
+	if !log.IsEnabledFor(slog.LevelDebug) {
 		return ""
 	}
 	if node == nil {
@@ -304,7 +303,7 @@ func NodeToString(node *CandidateNode) string {
 }
 
 func NodeContentToString(node *CandidateNode, depth int) string {
-	if !log.IsEnabledFor(logging.DEBUG) {
+	if !log.IsEnabledFor(slog.LevelDebug) {
 		return ""
 	}
 	var sb strings.Builder

pkg/yqlib/lib_test.go

@@ -24,7 +24,7 @@ type parseSnippetScenario struct {
 var parseSnippetScenarios = []parseSnippetScenario{
 	{
 		snippet:       ":",
-		expectedError: "yaml: did not find expected key",
+		expectedError: "yaml: while parsing a block mapping at <unknown position>: did not find expected key",
 	},
 	{
 		snippet: "",
@@ -300,6 +300,24 @@ func TestRecurseNodeObjectEqual(t *testing.T) {
 	test.AssertResult(t, true, recurseNodeObjectEqual(obj1, obj2))
 	test.AssertResult(t, false, recurseNodeObjectEqual(obj1, obj3))
 	test.AssertResult(t, false, recurseNodeObjectEqual(obj1, obj4))
+
+	// A null key must not match a null value in the other map.
+	// Regression test for https://issues.oss-fuzz.com/issues/383860504
+	nullKey := &CandidateNode{Kind: ScalarNode, Tag: "!!null"}
+	nullVal := &CandidateNode{Kind: ScalarNode, Tag: "!!null"}
+	intKey := createScalarNode(2, "2")
+	intKey.Tag = "!!int"
+	intVal := &CandidateNode{Kind: ScalarNode, Tag: "!!null"}
+
+	mapWithNullKey := &CandidateNode{
+		Kind:    MappingNode,
+		Content: []*CandidateNode{nullKey, nullVal},
+	}
+	mapWithIntKey := &CandidateNode{
+		Kind:    MappingNode,
+		Content: []*CandidateNode{intKey, intVal},
+	}
+	test.AssertResult(t, false, recurseNodeObjectEqual(mapWithNullKey, mapWithIntKey))
 }
 
 func TestParseInt(t *testing.T) {

pkg/yqlib/logger.go

@@ -0,0 +1,77 @@
+package yqlib
+
+import (
+	"fmt"
+	"log/slog"
+	"os"
+)
+
+// Logger wraps log/slog providing a printf-style interface used throughout yq.
+type Logger struct {
+	levelVar slog.LevelVar
+	slogger  *slog.Logger
+}
+
+func newLogger() *Logger {
+	l := &Logger{}
+	l.levelVar.Set(slog.LevelWarn)
+	handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: &l.levelVar})
+	l.slogger = slog.New(handler)
+	return l
+}
+
+// SetLevel sets the minimum log level.
+func (l *Logger) SetLevel(level slog.Level) {
+	l.levelVar.Set(level)
+}
+
+// GetLevel returns the current log level.
+func (l *Logger) GetLevel() slog.Level {
+	return l.levelVar.Level()
+}
+
+// IsEnabledFor returns true if the given level is enabled.
+func (l *Logger) IsEnabledFor(level slog.Level) bool {
+	return l.levelVar.Level() <= level
+}
+
+// SetSlogger replaces the underlying slog.Logger (e.g. to configure output format).
+func (l *Logger) SetSlogger(logger *slog.Logger) {
+	l.slogger = logger
+}
+
+func (l *Logger) Debug(msg string) {
+	if l.IsEnabledFor(slog.LevelDebug) {
+		l.slogger.Debug(msg)
+	}
+}
+
+func (l *Logger) Debugf(format string, args ...interface{}) {
+	if l.IsEnabledFor(slog.LevelDebug) {
+		l.slogger.Debug(fmt.Sprintf(format, args...))
+	}
+}
+
+func (l *Logger) Info(msg string) {
+	l.slogger.Info(msg)
+}
+
+func (l *Logger) Infof(format string, args ...interface{}) {
+	l.slogger.Info(fmt.Sprintf(format, args...))
+}
+
+func (l *Logger) Warning(msg string) {
+	l.slogger.Warn(msg)
+}
+
+func (l *Logger) Warningf(format string, args ...interface{}) {
+	l.slogger.Warn(fmt.Sprintf(format, args...))
+}
+
+func (l *Logger) Error(msg string) {
+	l.slogger.Error(msg)
+}
+
+func (l *Logger) Errorf(format string, args ...interface{}) {
+	l.slogger.Error(fmt.Sprintf(format, args...))
+}

pkg/yqlib/no_hcl.go

@@ -0,0 +1,11 @@
+//go:build yq_nohcl
+
+package yqlib
+
+func NewHclDecoder() Decoder {
+	return nil
+}
+
+func NewHclEncoder(_ HclPreferences) Encoder {
+	return nil
+}

pkg/yqlib/no_kyaml.go

@@ -0,0 +1,7 @@
+//go:build yq_nokyaml
+
+package yqlib
+
+func NewKYamlEncoder(_ KYamlPreferences) Encoder {
+	return nil
+}

pkg/yqlib/no_toml.go

@@ -5,3 +5,11 @@ package yqlib
 func NewTomlDecoder() Decoder {
 	return nil
 }
+
+func NewTomlEncoder() Encoder {
+	return nil
+}
+
+func NewTomlEncoderWithPrefs(prefs TomlPreferences) Encoder {
+	return nil
+}

pkg/yqlib/operation.go

@@ -25,7 +25,7 @@ var valueToStringFunc = func(p *Operation) string {
 }
 
 func createValueOperation(value interface{}, stringValue string) *Operation {
-	log.Debug("creating value op for string %v", stringValue)
+	log.Debugf("creating value op for string %v", stringValue)
 	var node = createScalarNode(value, stringValue)
 
 	return &Operation{
@@ -164,6 +164,8 @@ var stringInterpolationOpType = &operationType{Type: "STRING_INT", NumArgs: 0, P
 var loadOpType = &operationType{Type: "LOAD", NumArgs: 1, Precedence: 52, Handler: loadOperator, CheckForPostTraverse: true}
 var loadStringOpType = &operationType{Type: "LOAD_STRING", NumArgs: 1, Precedence: 52, Handler: loadStringOperator}
 
+var systemOpType = &operationType{Type: "SYSTEM", NumArgs: 1, Precedence: 50, Handler: systemOperator}
+
 var keysOpType = &operationType{Type: "KEYS", NumArgs: 0, Precedence: 52, Handler: keysOperator, CheckForPostTraverse: true}
 
 var collectObjectOpType = &operationType{Type: "COLLECT_OBJECT", NumArgs: 0, Precedence: 50, Handler: collectObjectOperator}