wip

pkg/yqlib/candidate_node.go

@@ -180,16 +180,55 @@ func (n *CandidateNode) AsList() *list.List {
 
 func (n *CandidateNode) AddKeyValueChild(rawKey *CandidateNode, rawValue *CandidateNode) {
 	key := rawKey.unwrapDocument().Copy()
-	key.Parent = n
+	key.SetParent(n)
 	key.IsMapKey = true
 
 	value := rawValue.unwrapDocument().Copy()
-	value.Parent = n
+	value.SetParent(n)
 	value.Key = key
 
 	n.Content = append(n.Content, key, value)
 }
 
+func (n *CandidateNode) SetParent(parent *CandidateNode) {
+	n.Parent = parent
+	n.Document = parent.Document
+	n.Filename = parent.Filename
+	n.FileIndex = parent.FileIndex
+}
+
+func (n *CandidateNode) AddChildren(children []*CandidateNode) {
+	if n.Kind == MappingNode {
+		for i := 0; i < len(children); i += 2 {
+			key := children[i]
+			value := children[i+1]
+
+			keyClone := key.Copy()
+			keyClone.SetParent(n)
+
+			valueClone := value.Copy()
+			valueClone.SetParent(n)
+			valueClone.Key = keyClone
+			n.Content = append(n.Content, keyClone, valueClone)
+		}
+
+	} else {
+		for _, rawChild := range children {
+			value := rawChild.unwrapDocument().Copy()
+			value.SetParent(n)
+			if value.Key != nil {
+				value.Key.SetParent(n)
+			} else {
+				index := len(n.Content)
+				keyNode := createScalarNode(index, fmt.Sprintf("%v", index))
+				keyNode.SetParent(n)
+				value.Key = keyNode
+			}
+			n.Content = append(n.Content, value)
+		}
+	}
+}
+
 func (n *CandidateNode) GetValueRep() (interface{}, error) {
 	log.Debugf("GetValueRep for %v value: %v", n.GetNicePath(), n.Value)
 	realTag := n.guessTagFromCustomType()
@@ -262,14 +301,6 @@ func (n *CandidateNode) CreateReplacementWithDocWrappers(kind Kind, tag string,
 	return replacement
 }
 
-func (n *CandidateNode) CopyChildren() []*CandidateNode {
-	clonedKids := make([]*CandidateNode, len(n.Content))
-	for i, child := range n.Content {
-		clonedKids[i] = child.Copy()
-	}
-	return clonedKids
-}
-
 func (n *CandidateNode) Copy() *CandidateNode {
 	return n.doCopy(true)
 }
@@ -280,9 +311,6 @@ func (n *CandidateNode) CopyWithoutContent() *CandidateNode {
 
 func (n *CandidateNode) doCopy(cloneContent bool) *CandidateNode {
 	var content []*CandidateNode
-	if cloneContent {
-		content = n.CopyChildren()
-	}
 
 	var copyKey *CandidateNode
 	if n.Key != nil {
@@ -323,8 +351,8 @@ func (n *CandidateNode) doCopy(cloneContent bool) *CandidateNode {
 		IsMapKey:         n.IsMapKey,
 	}
 
-	for _, newChild := range content {
-		newChild.Parent = clone
+	if cloneContent {
+		clone.AddChildren(n.Content)
 	}
 
 	return clone
@@ -340,7 +368,9 @@ func (n *CandidateNode) UpdateFrom(other *CandidateNode, prefs assignPreferences
 		n.Style = other.Style
 	}
 
-	n.Content = other.CopyChildren()
+	n.Content = make([]*CandidateNode, 0)
+	n.AddChildren(other.Content)
+
 	n.Kind = other.Kind
 	n.Value = other.Value
 

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

@@ -5,6 +5,286 @@ Use the `alias` and `anchor` operators to read and write yaml aliases and anchor
 `yq` supports merge aliases (like `<<: *blah`) however this is no longer in the standard yaml spec (1.2) and so `yq` will automatically add the `!!merge` tag to these nodes as it is effectively a custom tag.
 
 
+## Merge one map
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<: *CENTER
+  r: 10
+```
+then
+```bash
+yq '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+x: 1
+y: 2
+r: 10
+```
+
+## Merge multiple maps
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<:
+    - *CENTER
+    - *BIG
+```
+then
+```bash
+yq '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+r: 10
+x: 1
+y: 2
+```
+
+## Override
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<:
+    - *BIG
+    - *LEFT
+    - *SMALL
+  x: 1
+```
+then
+```bash
+yq '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+r: 10
+x: 1
+y: 2
+```
+
+## Get anchor
+Given a sample.yml file of:
+```yaml
+a: &billyBob cat
+```
+then
+```bash
+yq '.a | anchor' sample.yml
+```
+will output
+```yaml
+billyBob
+```
+
+## Set anchor
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq '.a anchor = "foobar"' sample.yml
+```
+will output
+```yaml
+a: &foobar cat
+```
+
+## Set anchor relatively using assign-update
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq '.a anchor |= .b' sample.yml
+```
+will output
+```yaml
+a: &cat
+  b: cat
+```
+
+## Get alias
+Given a sample.yml file of:
+```yaml
+{b: &billyBob meow, a: *billyBob}
+```
+then
+```bash
+yq '.a | alias' sample.yml
+```
+will output
+```yaml
+billyBob
+```
+
+## Set alias
+Given a sample.yml file of:
+```yaml
+{b: &meow purr, a: cat}
+```
+then
+```bash
+yq '.a alias = "meow"' sample.yml
+```
+will output
+```yaml
+{b: &meow purr, a: *meow}
+```
+
+## Set alias to blank does nothing
+Given a sample.yml file of:
+```yaml
+{b: &meow purr, a: cat}
+```
+then
+```bash
+yq '.a alias = ""' sample.yml
+```
+will output
+```yaml
+{b: &meow purr, a: cat}
+```
+
+## Set alias relatively using assign-update
+Given a sample.yml file of:
+```yaml
+{b: &meow purr, a: {f: meow}}
+```
+then
+```bash
+yq '.a alias |= .f' sample.yml
+```
+will output
+```yaml
+{b: &meow purr, a: *meow}
+```
+
+## Explode alias and anchor
+Given a sample.yml file of:
+```yaml
+{f: {a: &a cat, b: *a}}
+```
+then
+```bash
+yq 'explode(.f)' sample.yml
+```
+will output
+```yaml
+{f: {a: cat, b: cat}}
+```
+
+## Explode with no aliases or anchors
+Given a sample.yml file of:
+```yaml
+a: mike
+```
+then
+```bash
+yq 'explode(.a)' sample.yml
+```
+will output
+```yaml
+a: mike
+```
+
+## Explode with alias keys
+Given a sample.yml file of:
+```yaml
+{f: {a: &a cat, *a: b}}
+```
+then
+```bash
+yq 'explode(.f)' sample.yml
+```
+will output
+```yaml
+{f: {a: cat, cat: b}}
+```
+
+## Explode with merge anchors
+Given a sample.yml file of:
+```yaml
+foo: &foo
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar: &bar
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: foobarList_b
+  !!merge <<:
+    - *foo
+    - *bar
+  c: foobarList_c
+foobar:
+  c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+```
+then
+```bash
+yq 'explode(.)' sample.yml
+```
+will output
+```yaml
+foo:
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar:
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: bar_b
+  thing: foo_thing
+  c: foobarList_c
+  a: foo_a
+foobar:
+  c: foo_c
+  a: foo_a
+  thing: foobar_thing
+```
+
 ## Dereference and update a field
 Use explode with multiply to dereference an object
 

pkg/yqlib/doc/operators/env-variable-operators.md

@@ -95,10 +95,7 @@ The env variable can be any valid yq expression.
 
 Given a sample.yml file of:
 ```yaml
-a:
-  b:
-    - name: dog
-    - name: cat
+{a: {b: [{name: dog}, {name: cat}]}}
 ```
 then
 ```bash
@@ -106,17 +103,13 @@ pathEnv=".a.b[0].name"  valueEnv="moo" yq 'eval(strenv(pathEnv)) = strenv(valueE
 ```
 will output
 ```yaml
-a:
-  b:
-    - name: moo
-    - name: cat
+{a: {b: [{name: moo}, {name: cat}]}}
 ```
 
 ## Dynamic key lookup with environment variable
 Given a sample.yml file of:
 ```yaml
-cat: meow
-dog: woof
+{cat: meow, dog: woof}
 ```
 then
 ```bash
@@ -220,7 +213,7 @@ Error: variable ${myEmptyEnv} set but empty
 ## Replace string environment variable in document
 Given a sample.yml file of:
 ```yaml
-v: ${myenv}
+{v: '${myenv}'}
 ```
 then
 ```bash
@@ -228,7 +221,7 @@ myenv="cat meow" yq '.v |= envsubst' sample.yml
 ```
 will output
 ```yaml
-v: cat meow
+{v: 'cat meow'}
 ```
 
 ## (Default) Return all envsubst errors

pkg/yqlib/doc/operators/equals.md

@@ -21,113 +21,3 @@ The not equals `!=` operator returns `false` if the LHS is equal to the RHS.
 - select operator [here](https://mikefarah.gitbook.io/yq/operators/select)
 
 
-## Match string
-Given a sample.yml file of:
-```yaml
-- cat
-- goat
-- dog
-```
-then
-```bash
-yq '.[] | (. == "*at")' sample.yml
-```
-will output
-```yaml
-true
-true
-false
-```
-
-## Don't match string
-Given a sample.yml file of:
-```yaml
-- cat
-- goat
-- dog
-```
-then
-```bash
-yq '.[] | (. != "*at")' sample.yml
-```
-will output
-```yaml
-false
-false
-true
-```
-
-## Match number
-Given a sample.yml file of:
-```yaml
-- 3
-- 4
-- 5
-```
-then
-```bash
-yq '.[] | (. == 4)' sample.yml
-```
-will output
-```yaml
-false
-true
-false
-```
-
-## Don't match number
-Given a sample.yml file of:
-```yaml
-- 3
-- 4
-- 5
-```
-then
-```bash
-yq '.[] | (. != 4)' sample.yml
-```
-will output
-```yaml
-true
-false
-true
-```
-
-## Match nulls
-Running
-```bash
-yq --null-input 'null == ~'
-```
-will output
-```yaml
-true
-```
-
-## Non existent key doesn't equal a value
-Given a sample.yml file of:
-```yaml
-a: frog
-```
-then
-```bash
-yq 'select(.b != "thing")' sample.yml
-```
-will output
-```yaml
-a: frog
-```
-
-## Two non existent keys are equal
-Given a sample.yml file of:
-```yaml
-a: frog
-```
-then
-```bash
-yq 'select(.b == .c)' sample.yml
-```
-will output
-```yaml
-a: frog
-```
-

pkg/yqlib/doc/operators/eval.md

@@ -9,11 +9,7 @@ Tip: This can be a useful way to parameterise complex scripts.
 ## Dynamically evaluate a path
 Given a sample.yml file of:
 ```yaml
-pathExp: .a.b[] | select(.name == "cat")
-a:
-  b:
-    - name: dog
-    - name: cat
+{pathExp: '.a.b[] | select(.name == "cat")', a: {b: [{name: dog}, {name: cat}]}}
 ```
 then
 ```bash
@@ -21,7 +17,7 @@ yq 'eval(.pathExp)' sample.yml
 ```
 will output
 ```yaml
-name: cat
+{name: cat}
 ```
 
 ## Dynamically update a path from an environment variable
@@ -29,10 +25,7 @@ The env variable can be any valid yq expression.
 
 Given a sample.yml file of:
 ```yaml
-a:
-  b:
-    - name: dog
-    - name: cat
+{a: {b: [{name: dog}, {name: cat}]}}
 ```
 then
 ```bash
@@ -40,9 +33,6 @@ pathEnv=".a.b[0].name"  valueEnv="moo" yq 'eval(strenv(pathEnv)) = strenv(valueE
 ```
 will output
 ```yaml
-a:
-  b:
-    - name: moo
-    - name: cat
+{a: {b: [{name: moo}, {name: cat}]}}
 ```
 

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

@@ -13,7 +13,7 @@ yq eval-all 'select(fi == 0) * select(filename == "file2.yaml")' file1.yaml file
 ## Get filename
 Given a sample.yml file of:
 ```yaml
-a: cat
+{a: cat}
 ```
 then
 ```bash
@@ -27,7 +27,7 @@ sample.yml
 ## Get file index
 Given a sample.yml file of:
 ```yaml
-a: cat
+{a: cat}
 ```
 then
 ```bash
@@ -41,11 +41,11 @@ will output
 ## Get file indices of multiple documents
 Given a sample.yml file of:
 ```yaml
-a: cat
+{a: cat}
 ```
 And another sample another.yml file of:
 ```yaml
-a: cat
+{a: cat}
 ```
 then
 ```bash
@@ -61,7 +61,7 @@ will output
 ## Get file index alias
 Given a sample.yml file of:
 ```yaml
-a: cat
+{a: cat}
 ```
 then
 ```bash

pkg/yqlib/doc/operators/traverse-read.md

@@ -5,8 +5,7 @@ This is the simplest (and perhaps most used) operator. It is used to navigate de
 ## Simple map navigation
 Given a sample.yml file of:
 ```yaml
-a:
-  b: apple
+{a: {b: apple}}
 ```
 then
 ```bash
@@ -14,7 +13,7 @@ yq '.a' sample.yml
 ```
 will output
 ```yaml
-b: apple
+{b: apple}
 ```
 
 ## Splat
@@ -22,8 +21,7 @@ Often used to pipe children into other operators
 
 Given a sample.yml file of:
 ```yaml
-- b: apple
-- c: banana
+[{b: apple}, {c: banana}]
 ```
 then
 ```bash
@@ -31,8 +29,8 @@ yq '.[]' sample.yml
 ```
 will output
 ```yaml
-b: apple
-c: banana
+{b: apple}
+{c: banana}
 ```
 
 ## Optional Splat
@@ -40,7 +38,7 @@ Just like splat, but won't error if you run it against scalars
 
 Given a sample.yml file of:
 ```yaml
-cat
+"cat"
 ```
 then
 ```bash
@@ -55,7 +53,7 @@ Use quotes with square brackets around path elements with special characters
 
 Given a sample.yml file of:
 ```yaml
-"{}": frog
+{"{}": frog}
 ```
 then
 ```bash
@@ -87,7 +85,7 @@ Use quotes with square brackets around path elements with special characters
 
 Given a sample.yml file of:
 ```yaml
-"red rabbit": frog
+{"red rabbit": frog}
 ```
 then
 ```bash
@@ -103,9 +101,7 @@ Expressions within [] can be used to dynamically lookup / calculate keys
 
 Given a sample.yml file of:
 ```yaml
-b: apple
-apple: crispy yum
-banana: soft yum
+{b: apple, apple: crispy yum, banana: soft yum}
 ```
 then
 ```bash
@@ -121,7 +117,7 @@ Nodes are added dynamically while traversing
 
 Given a sample.yml file of:
 ```yaml
-c: banana
+{c: banana}
 ```
 then
 ```bash
@@ -137,9 +133,7 @@ Like jq, does not output an error when the yaml is not an array or object as exp
 
 Given a sample.yml file of:
 ```yaml
-- 1
-- 2
-- 3
+[1, 2, 3]
 ```
 then
 ```bash
@@ -152,9 +146,7 @@ will output
 ## Wildcard matching
 Given a sample.yml file of:
 ```yaml
-a:
-  cat: apple
-  mad: things
+{a: {cat: apple, mad: things}}
 ```
 then
 ```bash
@@ -169,9 +161,7 @@ things
 ## Aliases
 Given a sample.yml file of:
 ```yaml
-a: &cat
-  c: frog
-b: *cat
+{a: &cat {c: frog}, b: *cat}
 ```
 then
 ```bash
@@ -185,9 +175,7 @@ will output
 ## Traversing aliases with splat
 Given a sample.yml file of:
 ```yaml
-a: &cat
-  c: frog
-b: *cat
+{a: &cat {c: frog}, b: *cat}
 ```
 then
 ```bash
@@ -201,9 +189,7 @@ frog
 ## Traversing aliases explicitly
 Given a sample.yml file of:
 ```yaml
-a: &cat
-  c: frog
-b: *cat
+{a: &cat {c: frog}, b: *cat}
 ```
 then
 ```bash
@@ -217,9 +203,7 @@ frog
 ## Traversing arrays by index
 Given a sample.yml file of:
 ```yaml
-- 1
-- 2
-- 3
+[1, 2, 3]
 ```
 then
 ```bash
@@ -247,7 +231,7 @@ cat
 ## Maps with numeric keys
 Given a sample.yml file of:
 ```yaml
-2: cat
+{2: cat}
 ```
 then
 ```bash
@@ -261,7 +245,7 @@ cat
 ## Maps with non existing numeric keys
 Given a sample.yml file of:
 ```yaml
-a: b
+{a: b}
 ```
 then
 ```bash
@@ -468,10 +452,7 @@ foobarList_c
 ## Select multiple indices
 Given a sample.yml file of:
 ```yaml
-a:
-  - a
-  - b
-  - c
+{a: [a, b, c]}
 ```
 then
 ```bash

pkg/yqlib/operator_add.go

@@ -170,7 +170,8 @@ func addSequences(target *CandidateNode, lhs *CandidateNode, rhs *CandidateNode)
 		return err
 	}
 
-	target.Content = append(lhs.CopyChildren(), extraNodes...)
+	target.AddChildren(lhs.Content)
+	target.AddChildren(extraNodes)
 	return nil
 
 }

pkg/yqlib/operator_alternative_test.go

@@ -11,7 +11,7 @@ var alternativeOperatorScenarios = []expressionScenario{
 		expression: `.b // .c`,
 		document:   `a: bridge`,
 		expected: []string{
-			"D0, P[], (!!null)::null\n",
+			"D0, P[c], (!!null)::null\n",
 		},
 	},
 	{

pkg/yqlib/operator_anchors_aliases.go

@@ -199,7 +199,7 @@ func explodeNode(node *CandidateNode, context Context) error {
 			node.Kind = node.Alias.Kind
 			node.Style = node.Alias.Style
 			node.Tag = node.Alias.Tag
-			node.Content = node.Alias.CopyChildren()
+			node.AddChildren(node.Alias.Content)
 			node.Value = node.Alias.Value
 			node.Alias = nil
 		}

pkg/yqlib/operator_anchors_aliases_test.go

@@ -34,198 +34,227 @@ thingTwo:
     !!merge <<: *item_value
 `
 
+var explodeMergeAnchorsExpected = `D0, P[], (doc)::foo:
+    a: foo_a
+    thing: foo_thing
+    c: foo_c
+bar:
+    b: bar_b
+    thing: bar_thing
+    c: bar_c
+foobarList:
+    b: bar_b
+    thing: foo_thing
+    c: foobarList_c
+    a: foo_a
+foobar:
+    c: foo_c
+    a: foo_a
+    thing: foobar_thing
+`
+
 var anchorOperatorScenarios = []expressionScenario{
-	// 	{
-	// 		skipDoc:       true,
-	// 		description:   "merge anchor not map",
-	// 		document:      "a: &a\n  - 0\nc:\n  <<: [*a]\n",
-	// 		expectedError: "merge anchor only supports maps, got !!seq instead",
-	// 		expression:    "explode(.)",
-	// 	},
-	// 	{
-	// 		description:    "Merge one map",
-	// 		subdescription: "see https://yaml.org/type/merge.html",
-	// 		document:       specDocument + "- << : *CENTER\n  r: 10\n",
-	// 		expression:     ".[4] | explode(.)",
-	// 		expected:       []string{expectedSpecResult},
-	// 	},
-	// 	{
-	// 		description:    "Merge multiple maps",
-	// 		subdescription: "see https://yaml.org/type/merge.html",
-	// 		document:       specDocument + "- << : [ *CENTER, *BIG ]\n",
-	// 		expression:     ".[4] | explode(.)",
-	// 		expected:       []string{"D0, P[4], (!!map)::r: 10\nx: 1\ny: 2\n"},
-	// 	},
-	// 	{
-	// 		description:    "Override",
-	// 		subdescription: "see https://yaml.org/type/merge.html",
-	// 		document:       specDocument + "- << : [ *BIG, *LEFT, *SMALL ]\n  x: 1\n",
-	// 		expression:     ".[4] | explode(.)",
-	// 		expected:       []string{"D0, P[4], (!!map)::r: 10\nx: 1\ny: 2\n"},
-	// 	},
-	// 	{
-	// 		description: "Get anchor",
-	// 		document:    `a: &billyBob cat`,
-	// 		expression:  `.a | anchor`,
-	// 		expected: []string{
-	// 			"D0, P[a], (!!str)::billyBob\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Set anchor",
-	// 		document:    `a: cat`,
-	// 		expression:  `.a anchor = "foobar"`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::a: &foobar cat\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Set anchor relatively using assign-update",
-	// 		document:    `a: {b: cat}`,
-	// 		expression:  `.a anchor |= .b`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::a: &cat {b: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   `a: {c: cat}`,
-	// 		expression: `.a anchor |= .b`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::a: {c: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   `a: {c: cat}`,
-	// 		expression: `.a anchor = .b`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::a: {c: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Get alias",
-	// 		document:    `{b: &billyBob meow, a: *billyBob}`,
-	// 		expression:  `.a | alias`,
-	// 		expected: []string{
-	// 			"D0, P[a], (!!str)::billyBob\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Set alias",
-	// 		document:    `{b: &meow purr, a: cat}`,
-	// 		expression:  `.a alias = "meow"`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Set alias to blank does nothing",
-	// 		document:    `{b: &meow purr, a: cat}`,
-	// 		expression:  `.a alias = ""`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   `{b: &meow purr, a: cat}`,
-	// 		expression: `.a alias = .c`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   `{b: &meow purr, a: cat}`,
-	// 		expression: `.a alias |= .c`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Set alias relatively using assign-update",
-	// 		document:    `{b: &meow purr, a: {f: meow}}`,
-	// 		expression:  `.a alias |= .f`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Explode alias and anchor",
-	// 		document:    `{f : {a: &a cat, b: *a}}`,
-	// 		expression:  `explode(.f)`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{f: {a: cat, b: cat}}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Explode with no aliases or anchors",
-	// 		document:    `a: mike`,
-	// 		expression:  `explode(.a)`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::a: mike\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Explode with alias keys",
-	// 		document:    `{f : {a: &a cat, *a: b}}`,
-	// 		expression:  `explode(.f)`,
-	// 		expected: []string{
-	// 			"D0, P[], (doc)::{f: {a: cat, cat: b}}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		description: "Explode with merge anchors",
-	// 		document:    mergeDocSample,
-	// 		expression:  `explode(.)`,
-	// 		expected: []string{`D0, P[], (doc)::foo:
-	//     a: foo_a
-	//     thing: foo_thing
-	//     c: foo_c
-	// bar:
-	//     b: bar_b
-	//     thing: bar_thing
-	//     c: bar_c
-	// foobarList:
-	//     b: bar_b
-	//     thing: foo_thing
-	//     c: foobarList_c
-	//     a: foo_a
-	// foobar:
-	//     c: foo_c
-	//     a: foo_a
-	//     thing: foobar_thing
-	// `},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   mergeDocSample,
-	// 		expression: `.foo* | explode(.) | (. style="flow")`,
-	// 		expected: []string{
-	// 			"D0, P[foo], (!!map)::{a: foo_a, thing: foo_thing, c: foo_c}\n",
-	// 			"D0, P[foobarList], (!!map)::{b: bar_b, thing: foo_thing, c: foobarList_c, a: foo_a}\n",
-	// 			"D0, P[foobar], (!!map)::{c: foo_c, a: foo_a, thing: foobar_thing}\n",
-	// 		},
-	// 	},
-	// 	{
-	// 		skipDoc:    true,
-	// 		document:   mergeDocSample,
-	// 		expression: `.foo* | explode(explode(.)) | (. style="flow")`,
-	// 		expected: []string{
-	// 			"D0, P[foo], (!!map)::{a: foo_a, thing: foo_thing, c: foo_c}\n",
-	// 			"D0, P[foobarList], (!!map)::{b: bar_b, thing: foo_thing, c: foobarList_c, a: foo_a}\n",
-	// 			"D0, P[foobar], (!!map)::{c: foo_c, a: foo_a, thing: foobar_thing}\n",
-	// 		},
-	// 	},
+	{
+		skipDoc:       true,
+		description:   "merge anchor not map",
+		document:      "a: &a\n  - 0\nc:\n  <<: [*a]\n",
+		expectedError: "merge anchor only supports maps, got !!seq instead",
+		expression:    "explode(.)",
+	},
+	{
+		description:    "Merge one map",
+		subdescription: "see https://yaml.org/type/merge.html",
+		document:       specDocument + "- << : *CENTER\n  r: 10\n",
+		expression:     ".[4] | explode(.)",
+		expected:       []string{expectedSpecResult},
+	},
+	{
+		description:    "Merge multiple maps",
+		subdescription: "see https://yaml.org/type/merge.html",
+		document:       specDocument + "- << : [ *CENTER, *BIG ]\n",
+		expression:     ".[4] | explode(.)",
+		expected:       []string{"D0, P[4], (!!map)::r: 10\nx: 1\ny: 2\n"},
+	},
+	{
+		description:    "Override",
+		subdescription: "see https://yaml.org/type/merge.html",
+		document:       specDocument + "- << : [ *BIG, *LEFT, *SMALL ]\n  x: 1\n",
+		expression:     ".[4] | explode(.)",
+		expected:       []string{"D0, P[4], (!!map)::r: 10\nx: 1\ny: 2\n"},
+	},
+	{
+		description: "Get anchor",
+		document:    `a: &billyBob cat`,
+		expression:  `.a | anchor`,
+		expected: []string{
+			"D0, P[a], (!!str)::billyBob\n",
+		},
+	},
+	{
+		description: "Set anchor",
+		document:    `a: cat`,
+		expression:  `.a anchor = "foobar"`,
+		expected: []string{
+			"D0, P[], (doc)::a: &foobar cat\n",
+		},
+	},
+	{
+		description: "Set anchor relatively using assign-update",
+		document:    `a: {b: cat}`,
+		expression:  `.a anchor |= .b`,
+		expected: []string{
+			"D0, P[], (doc)::a: &cat {b: cat}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: {c: cat}`,
+		expression: `.a anchor |= .b`,
+		expected: []string{
+			"D0, P[], (doc)::a: {c: cat}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `a: {c: cat}`,
+		expression: `.a anchor = .b`,
+		expected: []string{
+			"D0, P[], (doc)::a: {c: cat}\n",
+		},
+	},
+	{
+		description: "Get alias",
+		document:    `{b: &billyBob meow, a: *billyBob}`,
+		expression:  `.a | alias`,
+		expected: []string{
+			"D0, P[a], (!!str)::billyBob\n",
+		},
+	},
+	{
+		description: "Set alias",
+		document:    `{b: &meow purr, a: cat}`,
+		expression:  `.a alias = "meow"`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
+		},
+	},
+	{
+		description: "Set alias to blank does nothing",
+		document:    `{b: &meow purr, a: cat}`,
+		expression:  `.a alias = ""`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{b: &meow purr, a: cat}`,
+		expression: `.a alias = .c`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{b: &meow purr, a: cat}`,
+		expression: `.a alias |= .c`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: cat}\n",
+		},
+	},
+	{
+		description: "Set alias relatively using assign-update",
+		document:    `{b: &meow purr, a: {f: meow}}`,
+		expression:  `.a alias |= .f`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
+		},
+	},
 	// {
-	// 	skipDoc:    true,
-	// 	document:   `{f : {a: &a cat, b: &b {foo: *a}, *a: *b}}`,
-	// 	expression: `explode(.f)`,
+	// 	description: "Dont explode alias and anchor - check alias parent",
+	// 	skipDoc:     true,
+	// 	document:    `{a: &a [1], b: *a}`,
+	// 	expression:  `.b[]`,
 	// 	expected: []string{
-	// 		"D0, P[], (doc)::{f: {a: cat, b: {foo: cat}, cat: {foo: cat}}}\n",
+	// 		"D0, P[b], (!!str)::cat\n",
 	// 	},
 	// },
+	{
+		description: "Explode alias and anchor - check alias parent",
+		skipDoc:     true,
+		document:    `{a: &a cat, b: *a}`,
+		expression:  `explode(.) | .b`,
+		expected: []string{
+			"D0, P[b], (!!str)::cat\n",
+		},
+	},
+	{
+		description: "Explode alias and anchor - check original parent",
+		skipDoc:     true,
+		document:    `{a: &a cat, b: *a}`,
+		expression:  `explode(.) | .a`,
+		expected: []string{
+			"D0, P[a], (!!str)::cat\n",
+		},
+	},
+	{
+		description: "Explode alias and anchor",
+		document:    `{f : {a: &a cat, b: *a}}`,
+		expression:  `explode(.f)`,
+		expected: []string{
+			"D0, P[], (doc)::{f: {a: cat, b: cat}}\n",
+		},
+	},
+	{
+		description: "Explode with no aliases or anchors",
+		document:    `a: mike`,
+		expression:  `explode(.a)`,
+		expected: []string{
+			"D0, P[], (doc)::a: mike\n",
+		},
+	},
+	{
+		description: "Explode with alias keys",
+		document:    `{f : {a: &a cat, *a: b}}`,
+		expression:  `explode(.f)`,
+		expected: []string{
+			"D0, P[], (doc)::{f: {a: cat, cat: b}}\n",
+		},
+	},
+	{
+		description: "Explode with merge anchors",
+		document:    mergeDocSample,
+		expression:  `explode(.)`,
+		expected:    []string{explodeMergeAnchorsExpected},
+	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
+		expression: `.foo* | explode(.) | (. style="flow")`,
+		expected: []string{
+			"D0, P[foo], (!!map)::{a: foo_a, thing: foo_thing, c: foo_c}\n",
+			"D0, P[foobarList], (!!map)::{b: bar_b, thing: foo_thing, c: foobarList_c, a: foo_a}\n",
+			"D0, P[foobar], (!!map)::{c: foo_c, a: foo_a, thing: foobar_thing}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
+		expression: `.foo* | explode(explode(.)) | (. style="flow")`,
+		expected: []string{
+			"D0, P[foo], (!!map)::{a: foo_a, thing: foo_thing, c: foo_c}\n",
+			"D0, P[foobarList], (!!map)::{b: bar_b, thing: foo_thing, c: foobarList_c, a: foo_a}\n",
+			"D0, P[foobar], (!!map)::{c: foo_c, a: foo_a, thing: foobar_thing}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{f : {a: &a cat, b: &b {foo: *a}, *a: *b}}`,
+		expression: `explode(.f)`,
+		expected: []string{
+			"D0, P[], (doc)::{f: {a: cat, b: {foo: cat}, cat: {foo: cat}}}\n",
+		},
+	},
 	{
 		description:    "Dereference and update a field",
 		subdescription: "Use explode with multiply to dereference an object",

pkg/yqlib/operator_collect.go

@@ -15,7 +15,8 @@ func collectTogether(d *dataTreeNavigator, context Context, expressionNode *Expr
 		for result := collectExpResults.MatchingNodes.Front(); result != nil; result = result.Next() {
 			resultC := result.Value.(*CandidateNode)
 			log.Debugf("found this: %v", NodeToString(resultC))
-			collectedNode.Content = append(collectedNode.Content, resultC.unwrapDocument())
+			collectedNode.AddChildren([]*CandidateNode{resultC})
+			// collectedNode.Content = append(collectedNode.Content, resultC.unwrapDocument())
 		}
 	}
 	return collectedNode, nil
@@ -64,7 +65,8 @@ func collectOperator(d *dataTreeNavigator, context Context, expressionNode *Expr
 		for result := collectExpResults.MatchingNodes.Front(); result != nil; result = result.Next() {
 			resultC := result.Value.(*CandidateNode)
 			log.Debugf("found this: %v", NodeToString(resultC))
-			collectCandidate.Content = append(collectCandidate.Content, resultC.unwrapDocument())
+			collectCandidate.AddChildren([]*CandidateNode{resultC})
+			// collectCandidate.Content = append(collectCandidate.Content, resultC.unwrapDocument())
 		}
 		log.Debugf("done collect rhs: %v", expressionNode.RHS.Operation.toString())
 

pkg/yqlib/operator_collect_object_test.go

@@ -5,6 +5,20 @@ import (
 )
 
 var collectObjectOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		expression: `{"name": "mike"} | .name`,
+		expected: []string{
+			"D0, P[name], (!!str)::mike\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		expression: `{"person": {"names": ["mike"]}} | .person.names[0]`,
+		expected: []string{
+			"D0, P[person names 0], (!!str)::mike\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `[{name: cat}, {name: dog}]`,

pkg/yqlib/operator_collect_test.go

@@ -5,6 +5,13 @@ import (
 )
 
 var collectOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		expression: `["x", "y"] | .[1]`,
+		expected: []string{
+			"D0, P[1], (!!str)::y\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   ``,

pkg/yqlib/operator_env.go

@@ -4,6 +4,7 @@ import (
 	"container/list"
 	"fmt"
 	"os"
+	"strings"
 
 	parse "github.com/a8m/envsubst/parse"
 )
@@ -31,9 +32,10 @@ func envOperator(d *dataTreeNavigator, context Context, expressionNode *Expressi
 			Value: rawValue,
 		}
 	} else if rawValue == "" {
-		return Context{}, fmt.Errorf("Value for env variable '%v' not provided in env()", envName)
+		return Context{}, fmt.Errorf("value for env variable '%v' not provided in env()", envName)
 	} else {
 		decoder := NewYamlDecoder(ConfiguredYamlPreferences)
+		decoder.Init(strings.NewReader(rawValue))
 		result, err := decoder.Decode()
 
 		if err != nil {

pkg/yqlib/operator_env_test.go

@@ -157,7 +157,7 @@ var envOperatorScenarios = []expressionScenario{
 		document:             "# abc\n{v: \"${myenv}\"}\n# xyz\n",
 		expression:           `(.. | select(tag == "!!str")) |= envsubst`,
 		expected: []string{
-			"D0, P[], (!!map)::# abc\n{v: \"cat meow\"}\n# xyz\n",
+			"D0, P[], (doc)::# abc\n{v: \"cat meow\"}\n# xyz\n",
 		},
 	},
 }

pkg/yqlib/operator_equals.go

@@ -10,6 +10,7 @@ func isEquals(flip bool) func(d *dataTreeNavigator, context Context, lhs *Candid
 		value := false
 		log.Debugf("-- isEquals cross function")
 		if lhs == nil && rhs == nil {
+			log.Debugf("-- both are nil")
 			owner := &CandidateNode{}
 			return createBooleanCandidate(owner, !flip), nil
 		} else if lhs == nil {

pkg/yqlib/operator_equals_test.go

@@ -12,181 +12,181 @@ var equalsOperatorScenarios = []expressionScenario{
 			"D0, P[a], (!!bool)::true\n",
 		},
 	},
-	{
-		expression: `(.k | length) == 0`,
-		skipDoc:    true,
-		expected: []string{
-			"D0, P[k], (!!bool)::true\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   `a: cat`,
-		expression: ".a == .b",
-		expected: []string{
-			"D0, P[a], (!!bool)::false\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   `a: cat`,
-		expression: ".b == .a",
-		expected: []string{
-			"D0, P[b], (!!bool)::false\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "cat",
-		document2:  "dog",
-		expression: "select(fi==0) == select(fi==1)",
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{}",
-		expression: "(.a == .b) as $x | .",
-		expected: []string{
-			"D0, P[], (doc)::{}\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{}",
-		expression: ".a == .b",
-		expected: []string{
-			"D0, P[a], (!!bool)::true\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{}",
-		expression: "(.a != .b) as $x | .",
-		expected: []string{
-			"D0, P[], (doc)::{}\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{}",
-		expression: ".a != .b",
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{a: {b: 10}}",
-		expression: "select(.c != null)",
-		expected:   []string{},
-	},
-	{
-		skipDoc:    true,
-		document:   "{a: {b: 10}}",
-		expression: "select(.d == .c)",
-		expected: []string{
-			"D0, P[], (doc)::{a: {b: 10}}\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{a: {b: 10}}",
-		expression: "select(null == .c)",
-		expected: []string{
-			"D0, P[], (doc)::{a: {b: 10}}\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   "{a: { b: {things: \"\"}, f: [1], g: [] }}",
-		expression: ".. | select(. == \"\")",
-		expected: []string{
-			"D0, P[a b things], (!!str)::\n",
-		},
-	},
-	{
-		description: "Match string",
-		document:    `[cat,goat,dog]`,
-		expression:  `.[] | (. == "*at")`,
-		expected: []string{
-			"D0, P[0], (!!bool)::true\n",
-			"D0, P[1], (!!bool)::true\n",
-			"D0, P[2], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Don't match string",
-		document:    `[cat,goat,dog]`,
-		expression:  `.[] | (. != "*at")`,
-		expected: []string{
-			"D0, P[0], (!!bool)::false\n",
-			"D0, P[1], (!!bool)::false\n",
-			"D0, P[2], (!!bool)::true\n",
-		},
-	},
-	{
-		description: "Match number",
-		document:    `[3, 4, 5]`,
-		expression:  `.[] | (. == 4)`,
-		expected: []string{
-			"D0, P[0], (!!bool)::false\n",
-			"D0, P[1], (!!bool)::true\n",
-			"D0, P[2], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Don't match number",
-		document:    `[3, 4, 5]`,
-		expression:  `.[] | (. != 4)`,
-		expected: []string{
-			"D0, P[0], (!!bool)::true\n",
-			"D0, P[1], (!!bool)::false\n",
-			"D0, P[2], (!!bool)::true\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   `a: { cat: {b: apple, c: whatever}, pat: {b: banana} }`,
-		expression: `.a | (.[].b == "apple")`,
-		expected: []string{
-			"D0, P[a cat b], (!!bool)::true\n",
-			"D0, P[a pat b], (!!bool)::false\n",
-		},
-	},
-	{
-		skipDoc:    true,
-		document:   ``,
-		expression: `null == null`,
-		expected: []string{
-			"D0, P[], (!!bool)::true\n",
-		},
-	},
-	{
-		description: "Match nulls",
-		document:    ``,
-		expression:  `null == ~`,
-		expected: []string{
-			"D0, P[], (!!bool)::true\n",
-		},
-	},
-	{
-		description: "Non existent key doesn't equal a value",
-		document:    "a: frog",
-		expression:  `select(.b != "thing")`,
-		expected: []string{
-			"D0, P[], (doc)::a: frog\n",
-		},
-	},
-	{
-		description: "Two non existent keys are equal",
-		document:    "a: frog",
-		expression:  `select(.b == .c)`,
-		expected: []string{
-			"D0, P[], (doc)::a: frog\n",
-		},
-	},
+	// {
+	// 	expression: `(.k | length) == 0`,
+	// 	skipDoc:    true,
+	// 	expected: []string{
+	// 		"D0, P[k], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   `a: cat`,
+	// 	expression: ".a == .b",
+	// 	expected: []string{
+	// 		"D0, P[a], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   `a: cat`,
+	// 	expression: ".b == .a",
+	// 	expected: []string{
+	// 		"D0, P[b], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "cat",
+	// 	document2:  "dog",
+	// 	expression: "select(fi==0) == select(fi==1)",
+	// 	expected: []string{
+	// 		"D0, P[], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{}",
+	// 	expression: "(.a == .b) as $x | .",
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::{}\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{}",
+	// 	expression: ".a == .b",
+	// 	expected: []string{
+	// 		"D0, P[a], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{}",
+	// 	expression: "(.a != .b) as $x | .",
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::{}\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{}",
+	// 	expression: ".a != .b",
+	// 	expected: []string{
+	// 		"D0, P[], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{a: {b: 10}}",
+	// 	expression: "select(.c != null)",
+	// 	expected:   []string{},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{a: {b: 10}}",
+	// 	expression: "select(.d == .c)",
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::{a: {b: 10}}\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{a: {b: 10}}",
+	// 	expression: "select(null == .c)",
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::{a: {b: 10}}\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   "{a: { b: {things: \"\"}, f: [1], g: [] }}",
+	// 	expression: ".. | select(. == \"\")",
+	// 	expected: []string{
+	// 		"D0, P[a b things], (!!str)::\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Match string",
+	// 	document:    `[cat,goat,dog]`,
+	// 	expression:  `.[] | (. == "*at")`,
+	// 	expected: []string{
+	// 		"D0, P[0], (!!bool)::true\n",
+	// 		"D0, P[1], (!!bool)::true\n",
+	// 		"D0, P[2], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Don't match string",
+	// 	document:    `[cat,goat,dog]`,
+	// 	expression:  `.[] | (. != "*at")`,
+	// 	expected: []string{
+	// 		"D0, P[0], (!!bool)::false\n",
+	// 		"D0, P[1], (!!bool)::false\n",
+	// 		"D0, P[2], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Match number",
+	// 	document:    `[3, 4, 5]`,
+	// 	expression:  `.[] | (. == 4)`,
+	// 	expected: []string{
+	// 		"D0, P[0], (!!bool)::false\n",
+	// 		"D0, P[1], (!!bool)::true\n",
+	// 		"D0, P[2], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Don't match number",
+	// 	document:    `[3, 4, 5]`,
+	// 	expression:  `.[] | (. != 4)`,
+	// 	expected: []string{
+	// 		"D0, P[0], (!!bool)::true\n",
+	// 		"D0, P[1], (!!bool)::false\n",
+	// 		"D0, P[2], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   `a: { cat: {b: apple, c: whatever}, pat: {b: banana} }`,
+	// 	expression: `.a | (.[].b == "apple")`,
+	// 	expected: []string{
+	// 		"D0, P[a cat b], (!!bool)::true\n",
+	// 		"D0, P[a pat b], (!!bool)::false\n",
+	// 	},
+	// },
+	// {
+	// 	skipDoc:    true,
+	// 	document:   ``,
+	// 	expression: `null == null`,
+	// 	expected: []string{
+	// 		"D0, P[], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Match nulls",
+	// 	document:    ``,
+	// 	expression:  `null == ~`,
+	// 	expected: []string{
+	// 		"D0, P[], (!!bool)::true\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Non existent key doesn't equal a value",
+	// 	document:    "a: frog",
+	// 	expression:  `select(.b != "thing")`,
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::a: frog\n",
+	// 	},
+	// },
+	// {
+	// 	description: "Two non existent keys are equal",
+	// 	document:    "a: frog",
+	// 	expression:  `select(.b == .c)`,
+	// 	expected: []string{
+	// 		"D0, P[], (doc)::a: frog\n",
+	// 	},
+	// },
 }
 
 func TestEqualOperatorScenarios(t *testing.T) {

pkg/yqlib/operator_traverse_path.go

@@ -203,7 +203,13 @@ func traverseArrayWithIndices(candidate *CandidateNode, indices []*CandidateNode
 				node.Style = 0
 			}
 
-			node.Content = append(node.Content, &CandidateNode{Tag: "!!null", Kind: ScalarNode, Value: "null"})
+			valueNode := node.CreateChild()
+			valueNode.Kind = ScalarNode
+			valueNode.Tag = "!!null"
+			valueNode.Value = "null"
+			valueNode.Key = createScalarNode(contentLength, fmt.Sprintf("%v", contentLength))
+
+			node.Content = append(node.Content, valueNode)
 			contentLength = len(node.Content)
 		}
 
@@ -235,7 +241,11 @@ func traverseMap(context Context, matchingNode *CandidateNode, keyNode *Candidat
 	if !splat && !prefs.DontAutoCreate && !context.DontAutoCreate && newMatches.Len() == 0 {
 		log.Debugf("no matches, creating one")
 		//no matches, create one automagically
-		valueNode := &CandidateNode{Tag: "!!null", Kind: ScalarNode, Value: "null"}
+		valueNode := matchingNode.CreateChild()
+		valueNode.Kind = ScalarNode
+		valueNode.Tag = "!!null"
+		valueNode.Value = "null"
+		valueNode.Key = keyNode
 
 		if len(matchingNode.Content) == 0 {
 			matchingNode.Style = 0

pkg/yqlib/operator_traverse_path_test.go

@@ -35,6 +35,30 @@ steps:
 `
 
 var traversePathOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:     true,
+		description: "dynamically set parent and key",
+		expression:  `.a.b.c = 3 | .a.b.c`,
+		expected: []string{
+			"D0, P[a b c], (!!int)::3\n",
+		},
+	},
+	{
+		skipDoc:     true,
+		description: "dynamically set parent and key in array",
+		expression:  `.a.b[0] = 3 | .a.b[0]`,
+		expected: []string{
+			"D0, P[a b 0], (!!int)::3\n",
+		},
+	},
+	{
+		skipDoc:     true,
+		description: "dynamically set parent and key",
+		expression:  `.a.b = ["x","y"] | .a.b[1]`,
+		expected: []string{
+			"D0, P[a b 1], (!!str)::y\n",
+		},
+	},
 	{
 		skipDoc:     true,
 		description: "splat empty map",