wip

cmd/root.go

@@ -5,6 +5,8 @@ import (
 	"os"
 	"strings"
 
+	"github.com/mikefarah/yq/v4/pkg/properties"
+	"github.com/mikefarah/yq/v4/pkg/xml"
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/spf13/cobra"
 	logging "gopkg.in/op/go-logging.v1"
@@ -117,27 +119,27 @@ yq -P -oy sample.json
 		panic(err)
 	}
 
-	rootCmd.PersistentFlags().StringVar(&yqlib.ConfiguredXMLPreferences.AttributePrefix, "xml-attribute-prefix", yqlib.ConfiguredXMLPreferences.AttributePrefix, "prefix for xml attributes")
+	rootCmd.PersistentFlags().StringVar(&xml.ConfiguredXMLPreferences.AttributePrefix, "xml-attribute-prefix", xml.ConfiguredXMLPreferences.AttributePrefix, "prefix for xml attributes")
 	if err = rootCmd.RegisterFlagCompletionFunc("xml-attribute-prefix", cobra.NoFileCompletions); err != nil {
 		panic(err)
 	}
-	rootCmd.PersistentFlags().StringVar(&yqlib.ConfiguredXMLPreferences.ContentName, "xml-content-name", yqlib.ConfiguredXMLPreferences.ContentName, "name for xml content (if no attribute name is present).")
+	rootCmd.PersistentFlags().StringVar(&xml.ConfiguredXMLPreferences.ContentName, "xml-content-name", xml.ConfiguredXMLPreferences.ContentName, "name for xml content (if no attribute name is present).")
 	if err = rootCmd.RegisterFlagCompletionFunc("xml-content-name", cobra.NoFileCompletions); err != nil {
 		panic(err)
 	}
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredXMLPreferences.StrictMode, "xml-strict-mode", yqlib.ConfiguredXMLPreferences.StrictMode, "enables strict parsing of XML. See https://pkg.go.dev/encoding/xml for more details.")
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredXMLPreferences.KeepNamespace, "xml-keep-namespace", yqlib.ConfiguredXMLPreferences.KeepNamespace, "enables keeping namespace after parsing attributes")
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredXMLPreferences.UseRawToken, "xml-raw-token", yqlib.ConfiguredXMLPreferences.UseRawToken, "enables using RawToken method instead Token. Commonly disables namespace translations. See https://pkg.go.dev/encoding/xml#Decoder.RawToken for details.")
-	rootCmd.PersistentFlags().StringVar(&yqlib.ConfiguredXMLPreferences.ProcInstPrefix, "xml-proc-inst-prefix", yqlib.ConfiguredXMLPreferences.ProcInstPrefix, "prefix for xml processing instructions (e.g. <?xml version=\"1\"?>)")
+	rootCmd.PersistentFlags().BoolVar(&xml.ConfiguredXMLPreferences.StrictMode, "xml-strict-mode", xml.ConfiguredXMLPreferences.StrictMode, "enables strict parsing of XML. See https://pkg.go.dev/encoding/xml for more details.")
+	rootCmd.PersistentFlags().BoolVar(&xml.ConfiguredXMLPreferences.KeepNamespace, "xml-keep-namespace", xml.ConfiguredXMLPreferences.KeepNamespace, "enables keeping namespace after parsing attributes")
+	rootCmd.PersistentFlags().BoolVar(&xml.ConfiguredXMLPreferences.UseRawToken, "xml-raw-token", xml.ConfiguredXMLPreferences.UseRawToken, "enables using RawToken method instead Token. Commonly disables namespace translations. See https://pkg.go.dev/encoding/xml#Decoder.RawToken for details.")
+	rootCmd.PersistentFlags().StringVar(&xml.ConfiguredXMLPreferences.ProcInstPrefix, "xml-proc-inst-prefix", xml.ConfiguredXMLPreferences.ProcInstPrefix, "prefix for xml processing instructions (e.g. <?xml version=\"1\"?>)")
 	if err = rootCmd.RegisterFlagCompletionFunc("xml-proc-inst-prefix", cobra.NoFileCompletions); err != nil {
 		panic(err)
 	}
-	rootCmd.PersistentFlags().StringVar(&yqlib.ConfiguredXMLPreferences.DirectiveName, "xml-directive-name", yqlib.ConfiguredXMLPreferences.DirectiveName, "name for xml directives (e.g. <!DOCTYPE thing cat>)")
+	rootCmd.PersistentFlags().StringVar(&xml.ConfiguredXMLPreferences.DirectiveName, "xml-directive-name", xml.ConfiguredXMLPreferences.DirectiveName, "name for xml directives (e.g. <!DOCTYPE thing cat>)")
 	if err = rootCmd.RegisterFlagCompletionFunc("xml-directive-name", cobra.NoFileCompletions); err != nil {
 		panic(err)
 	}
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredXMLPreferences.SkipProcInst, "xml-skip-proc-inst", yqlib.ConfiguredXMLPreferences.SkipProcInst, "skip over process instructions (e.g. <?xml version=\"1\"?>)")
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredXMLPreferences.SkipDirectives, "xml-skip-directives", yqlib.ConfiguredXMLPreferences.SkipDirectives, "skip over directives (e.g. <!DOCTYPE thing cat>)")
+	rootCmd.PersistentFlags().BoolVar(&xml.ConfiguredXMLPreferences.SkipProcInst, "xml-skip-proc-inst", xml.ConfiguredXMLPreferences.SkipProcInst, "skip over process instructions (e.g. <?xml version=\"1\"?>)")
+	rootCmd.PersistentFlags().BoolVar(&xml.ConfiguredXMLPreferences.SkipDirectives, "xml-skip-directives", xml.ConfiguredXMLPreferences.SkipDirectives, "skip over directives (e.g. <!DOCTYPE thing cat>)")
 
 	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredCsvPreferences.AutoParse, "csv-auto-parse", yqlib.ConfiguredCsvPreferences.AutoParse, "parse CSV YAML/JSON values")
 	rootCmd.PersistentFlags().Var(newRuneVar(&yqlib.ConfiguredCsvPreferences.Separator), "csv-separator", "CSV Separator character")
@@ -155,8 +157,8 @@ yq -P -oy sample.json
 	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredLuaPreferences.UnquotedKeys, "lua-unquoted", yqlib.ConfiguredLuaPreferences.UnquotedKeys, "output unquoted string keys (e.g. {foo=\"bar\"})")
 	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredLuaPreferences.Globals, "lua-globals", yqlib.ConfiguredLuaPreferences.Globals, "output keys as top-level global variables")
 
-	rootCmd.PersistentFlags().StringVar(&yqlib.ConfiguredPropertiesPreferences.KeyValueSeparator, "properties-separator", yqlib.ConfiguredPropertiesPreferences.KeyValueSeparator, "separator to use between keys and values")
-	rootCmd.PersistentFlags().BoolVar(&yqlib.ConfiguredPropertiesPreferences.UseArrayBrackets, "properties-array-brackets", yqlib.ConfiguredPropertiesPreferences.UseArrayBrackets, "use [x] in array paths (e.g. for SpringBoot)")
+	rootCmd.PersistentFlags().StringVar(&properties.ConfiguredPropertiesPreferences.KeyValueSeparator, "properties-separator", properties.ConfiguredPropertiesPreferences.KeyValueSeparator, "separator to use between keys and values")
+	rootCmd.PersistentFlags().BoolVar(&properties.ConfiguredPropertiesPreferences.UseArrayBrackets, "properties-array-brackets", properties.ConfiguredPropertiesPreferences.UseArrayBrackets, "use [x] in array paths (e.g. for SpringBoot)")
 
 	rootCmd.PersistentFlags().BoolVar(&yqlib.StringInterpolationEnabled, "string-interpolation", yqlib.StringInterpolationEnabled, "Toggles strings interpolation of \\(exp)")
 

cmd/utils.go

@@ -6,6 +6,8 @@ import (
 	"os"
 	"strings"
 
+	"github.com/mikefarah/yq/v4/pkg/properties"
+	"github.com/mikefarah/yq/v4/pkg/xml"
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/spf13/cobra"
 	"gopkg.in/op/go-logging.v1"
@@ -102,7 +104,7 @@ func initCommand(cmd *cobra.Command, args []string) (string, []string, error) {
 	yqlib.GetLogger().Debug("Using output format %v", outputFormat)
 
 	if outputFormatType == yqlib.YamlFormat ||
-		outputFormatType == yqlib.PropertiesFormat {
+		outputFormatType == properties.PropertiesFormat {
 		unwrapScalar = true
 	}
 	if unwrapScalarFlag.IsExplicitlySet() {
@@ -148,12 +150,12 @@ func configureEncoder() (yqlib.Encoder, error) {
 	if err != nil {
 		return nil, err
 	}
-	yqlib.ConfiguredXMLPreferences.Indent = indent
+	xml.ConfiguredXMLPreferences.Indent = indent
 	yqlib.ConfiguredYamlPreferences.Indent = indent
 	yqlib.ConfiguredJSONPreferences.Indent = indent
 
 	yqlib.ConfiguredYamlPreferences.UnwrapScalar = unwrapScalar
-	yqlib.ConfiguredPropertiesPreferences.UnwrapScalar = unwrapScalar
+	properties.ConfiguredPropertiesPreferences.UnwrapScalar = unwrapScalar
 	yqlib.ConfiguredJSONPreferences.UnwrapScalar = unwrapScalar
 
 	yqlib.ConfiguredYamlPreferences.ColorsEnabled = colorsEnabled

pkg/properties/decoder_properties.go

@@ -1,4 +1,4 @@
-package yqlib
+package properties
 
 import (
 	"bytes"
@@ -8,16 +8,17 @@ import (
 	"strings"
 
 	"github.com/magiconair/properties"
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
 )
 
 type propertiesDecoder struct {
 	reader   io.Reader
 	finished bool
-	d        DataTreeNavigator
+	d        yqlib.DataTreeNavigator
 }
 
-func NewPropertiesDecoder() Decoder {
-	return &propertiesDecoder{d: NewDataTreeNavigator(), finished: false}
+func NewPropertiesDecoder() yqlib.Decoder {
+	return &propertiesDecoder{d: yqlib.NewDataTreeNavigator(), finished: false}
 }
 
 func (dec *propertiesDecoder) Init(reader io.Reader) error {
@@ -47,31 +48,18 @@ func (dec *propertiesDecoder) processComment(c string) string {
 	return "# " + c
 }
 
-func (dec *propertiesDecoder) applyPropertyComments(context Context, path []interface{}, comments []string) error {
-	assignmentOp := &Operation{OperationType: assignOpType, Preferences: assignPreferences{}}
-
-	rhsCandidateNode := &CandidateNode{
+func (dec *propertiesDecoder) applyPropertyComments(context yqlib.Context, path []interface{}, comments []string) error {
+	rhsCandidateNode := &yqlib.CandidateNode{
 		Tag:         "!!str",
 		Value:       fmt.Sprintf("%v", path[len(path)-1]),
 		HeadComment: dec.processComment(strings.Join(comments, "\n")),
-		Kind:        ScalarNode,
+		Kind:        yqlib.ScalarNode,
 	}
-
-	rhsCandidateNode.Tag = rhsCandidateNode.guessTagFromCustomType()
-
-	rhsOp := &Operation{OperationType: referenceOpType, CandidateNode: rhsCandidateNode}
-
-	assignmentOpNode := &ExpressionNode{
-		Operation: assignmentOp,
-		LHS:       createTraversalTree(path, traversePreferences{}, true),
-		RHS:       &ExpressionNode{Operation: rhsOp},
-	}
-
-	_, err := dec.d.GetMatchingNodes(context, assignmentOpNode)
-	return err
+	rhsCandidateNode.Tag = rhsCandidateNode.GuessTagFromCustomType()
+	return dec.d.DeeplyAssignKey(context, path, rhsCandidateNode)
 }
 
-func (dec *propertiesDecoder) applyProperty(context Context, properties *properties.Properties, key string) error {
+func (dec *propertiesDecoder) applyProperty(context yqlib.Context, properties *properties.Properties, key string) error {
 	value, _ := properties.Get(key)
 	path := parsePropKey(key)
 
@@ -83,13 +71,13 @@ func (dec *propertiesDecoder) applyProperty(context Context, properties *propert
 		}
 	}
 
-	rhsNode := createStringScalarNode(value)
-	rhsNode.Tag = rhsNode.guessTagFromCustomType()
+	rhsNode := yqlib.CreateStringScalarNode(value)
+	rhsNode.Tag = rhsNode.GuessTagFromCustomType()
 
 	return dec.d.DeeplyAssign(context, path, rhsNode)
 }
 
-func (dec *propertiesDecoder) Decode() (*CandidateNode, error) {
+func (dec *propertiesDecoder) Decode() (*yqlib.CandidateNode, error) {
 	if dec.finished {
 		return nil, io.EOF
 	}
@@ -108,12 +96,12 @@ func (dec *propertiesDecoder) Decode() (*CandidateNode, error) {
 	}
 	properties.DisableExpansion = true
 
-	rootMap := &CandidateNode{
-		Kind: MappingNode,
+	rootMap := &yqlib.CandidateNode{
+		Kind: yqlib.MappingNode,
 		Tag:  "!!map",
 	}
 
-	context := Context{}
+	context := yqlib.Context{}
 	context = context.SingleChildContext(rootMap)
 
 	for _, key := range properties.Keys() {

pkg/properties/encoder_properties.go

@@ -1,4 +1,4 @@
-package yqlib
+package properties
 
 import (
 	"bufio"
@@ -8,13 +8,14 @@ import (
 	"strings"
 
 	"github.com/magiconair/properties"
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
 )
 
 type propertiesEncoder struct {
 	prefs PropertiesPreferences
 }
 
-func NewPropertiesEncoder(prefs PropertiesPreferences) Encoder {
+func NewPropertiesEncoder(prefs PropertiesPreferences) yqlib.Encoder {
 	return &propertiesEncoder{
 		prefs: prefs,
 	}
@@ -43,7 +44,7 @@ func (pe *propertiesEncoder) PrintLeadingContent(writer io.Writer, content strin
 			}
 
 		} else {
-			if err := writeString(writer, readline); err != nil {
+			if err := yqlib.WriteString(writer, readline); err != nil {
 				return err
 			}
 		}
@@ -51,7 +52,7 @@ func (pe *propertiesEncoder) PrintLeadingContent(writer io.Writer, content strin
 		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 {
+				if err := yqlib.WriteString(writer, "\n"); err != nil {
 					return err
 				}
 			}
@@ -61,13 +62,13 @@ func (pe *propertiesEncoder) PrintLeadingContent(writer io.Writer, content strin
 	return nil
 }
 
-func (pe *propertiesEncoder) Encode(writer io.Writer, node *CandidateNode) error {
+func (pe *propertiesEncoder) Encode(writer io.Writer, node *yqlib.CandidateNode) error {
 
-	if node.Kind == ScalarNode {
-		return writeString(writer, node.Value+"\n")
+	if node.Kind == yqlib.ScalarNode {
+		return yqlib.WriteString(writer, node.Value+"\n")
 	}
 
-	mapKeysToStrings(node)
+	node.ConvertKeysToStrings()
 	p := properties.NewProperties()
 	p.WriteSeparator = pe.prefs.KeyValueSeparator
 	err := pe.doEncode(p, node, "", nil)
@@ -79,19 +80,19 @@ func (pe *propertiesEncoder) Encode(writer io.Writer, node *CandidateNode) error
 	return err
 }
 
-func (pe *propertiesEncoder) doEncode(p *properties.Properties, node *CandidateNode, path string, keyNode *CandidateNode) error {
+func (pe *propertiesEncoder) doEncode(p *properties.Properties, node *yqlib.CandidateNode, path string, keyNode *yqlib.CandidateNode) error {
 
 	comments := ""
 	if keyNode != nil {
 		// include the key node comments if present
-		comments = headAndLineComment(keyNode)
+		comments = keyNode.CleanHeadAndLineComment()
 	}
-	comments = comments + headAndLineComment(node)
+	comments = comments + node.CleanHeadAndLineComment()
 	commentsWithSpaces := strings.ReplaceAll(comments, "\n", "\n ")
 	p.SetComments(path, strings.Split(commentsWithSpaces, "\n"))
 
 	switch node.Kind {
-	case ScalarNode:
+	case yqlib.ScalarNode:
 		var nodeValue string
 		if pe.prefs.UnwrapScalar || !strings.Contains(node.Value, " ") {
 			nodeValue = node.Value
@@ -100,11 +101,11 @@ func (pe *propertiesEncoder) doEncode(p *properties.Properties, node *CandidateN
 		}
 		_, _, err := p.Set(path, nodeValue)
 		return err
-	case SequenceNode:
+	case yqlib.SequenceNode:
 		return pe.encodeArray(p, node.Content, path)
-	case MappingNode:
+	case yqlib.MappingNode:
 		return pe.encodeMap(p, node.Content, path)
-	case AliasNode:
+	case yqlib.AliasNode:
 		return pe.doEncode(p, node.Alias, path, nil)
 	default:
 		return fmt.Errorf("Unsupported node %v", node.Tag)
@@ -125,7 +126,7 @@ func (pe *propertiesEncoder) appendPath(path string, key interface{}) string {
 	return fmt.Sprintf("%v.%v", path, key)
 }
 
-func (pe *propertiesEncoder) encodeArray(p *properties.Properties, kids []*CandidateNode, path string) error {
+func (pe *propertiesEncoder) encodeArray(p *properties.Properties, kids []*yqlib.CandidateNode, path string) error {
 	for index, child := range kids {
 		err := pe.doEncode(p, child, pe.appendPath(path, index), nil)
 		if err != nil {
@@ -135,7 +136,7 @@ func (pe *propertiesEncoder) encodeArray(p *properties.Properties, kids []*Candi
 	return nil
 }
 
-func (pe *propertiesEncoder) encodeMap(p *properties.Properties, kids []*CandidateNode, path string) error {
+func (pe *propertiesEncoder) encodeMap(p *properties.Properties, kids []*yqlib.CandidateNode, path string) error {
 	for index := 0; index < len(kids); index = index + 2 {
 		key := kids[index]
 		value := kids[index+1]

pkg/properties/encoder_properties_test.go

@@ -1,4 +1,4 @@
-package yqlib
+package properties
 
 import (
 	"bufio"

pkg/properties/properties.go

@@ -0,0 +1,45 @@
+package properties
+
+import "github.com/mikefarah/yq/v4/pkg/yqlib"
+
+type PropertiesPreferences struct {
+	UnwrapScalar      bool
+	KeyValueSeparator string
+	UseArrayBrackets  bool
+}
+
+func NewDefaultPropertiesPreferences() PropertiesPreferences {
+	return PropertiesPreferences{
+		UnwrapScalar:      true,
+		KeyValueSeparator: " = ",
+		UseArrayBrackets:  false,
+	}
+}
+
+func (p *PropertiesPreferences) Copy() PropertiesPreferences {
+	return PropertiesPreferences{
+		UnwrapScalar:      p.UnwrapScalar,
+		KeyValueSeparator: p.KeyValueSeparator,
+		UseArrayBrackets:  p.UseArrayBrackets,
+	}
+}
+
+var PropertiesFormat = &yqlib.Format{"props", []string{"p", "properties"}, "properties",
+	func() yqlib.Encoder { return NewPropertiesEncoder(ConfiguredPropertiesPreferences) },
+	func() yqlib.Decoder { return NewPropertiesDecoder() },
+	nil,
+}
+
+var propertyYqRules = []*yqlib.ParticipleYqRule{
+	{"PropertiesDecode", `from_?props|@propsd`, yqlib.CreateDecodeOpYqAction(PropertiesFormat), 0},
+	{"PropsEncode", `to_?props|@props`, yqlib.CreateEncodeOpYqAction(PropertiesFormat, 2), 0},
+	{"LoadProperties", `load_?props`, yqlib.CreateLoadOpYqAction(NewPropertiesDecoder()), 0},
+}
+
+func RegisterPropertiesFormat() {
+	yqlib.RegisterFormat(PropertiesFormat)
+	yqlib.RegisterRules(propertyYqRules)
+
+}
+
+var ConfiguredPropertiesPreferences = NewDefaultPropertiesPreferences()

pkg/xml/decoder_xml.go

@@ -1,6 +1,6 @@
 //go:build !yq_noxml
 
-package yqlib
+package xml
 
 import (
 	"encoding/xml"
@@ -11,6 +11,7 @@ import (
 	"strings"
 	"unicode"
 
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"golang.org/x/net/html/charset"
 )
 
@@ -21,7 +22,7 @@ type xmlDecoder struct {
 	prefs        XmlPreferences
 }
 
-func NewXMLDecoder(prefs XmlPreferences) Decoder {
+func NewXMLDecoder(prefs XmlPreferences) yqlib.Decoder {
 	return &xmlDecoder{
 		finished: false,
 		prefs:    prefs,
@@ -35,8 +36,8 @@ func (dec *xmlDecoder) Init(reader io.Reader) error {
 	return nil
 }
 
-func (dec *xmlDecoder) createSequence(nodes []*xmlNode) (*CandidateNode, error) {
-	yamlNode := &CandidateNode{Kind: SequenceNode, Tag: "!!seq"}
+func (dec *xmlDecoder) createSequence(nodes []*xmlNode) (*yqlib.CandidateNode, error) {
+	yamlNode := &yqlib.CandidateNode{Kind: yqlib.SequenceNode, Tag: "!!seq"}
 	for _, child := range nodes {
 		yamlChild, err := dec.convertToYamlNode(child)
 		if err != nil {
@@ -63,14 +64,14 @@ func (dec *xmlDecoder) processComment(c string) string {
 	return replacement
 }
 
-func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
-	log.Debug("createMap: headC: %v, lineC: %v, footC: %v", n.HeadComment, n.LineComment, n.FootComment)
-	yamlNode := &CandidateNode{Kind: MappingNode, Tag: "!!map"}
+func (dec *xmlDecoder) createMap(n *xmlNode) (*yqlib.CandidateNode, error) {
+	yqlib.GetLogger().Debug("createMap: headC: %v, lineC: %v, footC: %v", n.HeadComment, n.LineComment, n.FootComment)
+	yamlNode := &yqlib.CandidateNode{Kind: yqlib.MappingNode, Tag: "!!map"}
 
 	if len(n.Data) > 0 {
-		log.Debugf("creating content node for map: %v", dec.prefs.ContentName)
+		yqlib.GetLogger().Debugf("creating content node for map: %v", dec.prefs.ContentName)
 		label := dec.prefs.ContentName
-		labelNode := createScalarNode(label, label)
+		labelNode := yqlib.CreateScalarNode(label, label)
 		labelNode.HeadComment = dec.processComment(n.HeadComment)
 		labelNode.LineComment = dec.processComment(n.LineComment)
 		labelNode.FootComment = dec.processComment(n.FootComment)
@@ -80,19 +81,19 @@ func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
 	for i, keyValuePair := range n.Children {
 		label := keyValuePair.K
 		children := keyValuePair.V
-		labelNode := createScalarNode(label, label)
-		var valueNode *CandidateNode
+		labelNode := yqlib.CreateScalarNode(label, label)
+		var valueNode *yqlib.CandidateNode
 		var err error
 
 		if i == 0 {
-			log.Debugf("head comment here")
+			yqlib.GetLogger().Debugf("head comment here")
 			labelNode.HeadComment = dec.processComment(n.HeadComment)
 
 		}
-		log.Debugf("label=%v, i=%v, keyValuePair.FootComment: %v", label, i, keyValuePair.FootComment)
+		yqlib.GetLogger().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))
+		yqlib.GetLogger().Debug("len of children in %v is %v", label, len(children))
 		if len(children) > 1 {
 			valueNode, err = dec.createSequence(children)
 			if err != nil {
@@ -105,7 +106,7 @@ 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)
+					yqlib.GetLogger().Debug("scalar comment hack, currentlabel [%v]", labelNode.HeadComment)
 					labelNode.HeadComment = joinComments([]string{labelNode.HeadComment, strings.TrimSpace(children[0].HeadComment)}, "\n")
 					children[0].HeadComment = ""
 				} else {
@@ -125,33 +126,33 @@ func (dec *xmlDecoder) createMap(n *xmlNode) (*CandidateNode, error) {
 	return yamlNode, nil
 }
 
-func (dec *xmlDecoder) createValueNodeFromData(values []string) *CandidateNode {
+func (dec *xmlDecoder) createValueNodeFromData(values []string) *yqlib.CandidateNode {
 	switch len(values) {
 	case 0:
-		return createScalarNode(nil, "")
+		return yqlib.CreateScalarNode(nil, "")
 	case 1:
-		return createScalarNode(values[0], values[0])
+		return yqlib.CreateScalarNode(values[0], values[0])
 	default:
-		content := make([]*CandidateNode, 0)
+		content := make([]*yqlib.CandidateNode, 0)
 		for _, value := range values {
-			content = append(content, createScalarNode(value, value))
+			content = append(content, yqlib.CreateScalarNode(value, value))
 		}
-		return &CandidateNode{
-			Kind:    SequenceNode,
+		return &yqlib.CandidateNode{
+			Kind:    yqlib.SequenceNode,
 			Tag:     "!!seq",
 			Content: content,
 		}
 	}
 }
 
-func (dec *xmlDecoder) convertToYamlNode(n *xmlNode) (*CandidateNode, error) {
+func (dec *xmlDecoder) convertToYamlNode(n *xmlNode) (*yqlib.CandidateNode, error) {
 	if len(n.Children) > 0 {
 		return dec.createMap(n)
 	}
 
 	scalar := dec.createValueNodeFromData(n.Data)
 
-	log.Debug("scalar (%v), headC: %v, lineC: %v, footC: %v", scalar.Tag, n.HeadComment, n.LineComment, n.FootComment)
+	yqlib.GetLogger().Debug("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" {
@@ -164,7 +165,7 @@ func (dec *xmlDecoder) convertToYamlNode(n *xmlNode) (*CandidateNode, error) {
 	return scalar, nil
 }
 
-func (dec *xmlDecoder) Decode() (*CandidateNode, error) {
+func (dec *xmlDecoder) Decode() (*yqlib.CandidateNode, error) {
 	if dec.finished {
 		return nil, io.EOF
 	}
@@ -211,17 +212,17 @@ func (n *xmlNode) AddChild(s string, c *xmlNode) {
 	if n.Children == nil {
 		n.Children = make([]*xmlChildrenKv, 0)
 	}
-	log.Debug("looking for %s", s)
+	yqlib.GetLogger().Debug("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)
+			yqlib.GetLogger().Debug("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))
+			yqlib.GetLogger().Debug("yay len of children in %v is %v", s, len(childEntry.V))
 			return
 		}
 	}
-	log.Debug("not there, making a new one %s", s)
+	yqlib.GetLogger().Debug("not there, making a new one %s", s)
 	n.Children = append(n.Children, &xmlChildrenKv{K: s, V: []*xmlNode{c}})
 }
 
@@ -267,7 +268,7 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 
 		switch se := t.(type) {
 		case xml.StartElement:
-			log.Debug("start element %v", se.Name.Local)
+			yqlib.GetLogger().Debug("start element %v", se.Name.Local)
 			elem.state = "started"
 			// Build new a new current element and link it to its parent
 			elem = &element{
@@ -296,14 +297,14 @@ 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)
+				yqlib.GetLogger().Debug("chardata [%v] for %v", elem.n.Data, elem.label)
 			}
 		case xml.EndElement:
 			if elem == nil {
-				log.Debug("no element, probably bad xml")
+				yqlib.GetLogger().Debug("no element, probably bad xml")
 				continue
 			}
-			log.Debug("end element %v", elem.label)
+			yqlib.GetLogger().Debug("end element %v", elem.label)
 			elem.state = "finished"
 			// And add it to its parent list
 			if elem.parent != nil {
@@ -319,10 +320,10 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 				applyFootComment(elem, commentStr)
 
 			} else if elem.state == "chardata" {
-				log.Debug("got a line comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
+				yqlib.GetLogger().Debug("got a line comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
 				elem.n.LineComment = joinComments([]string{elem.n.LineComment, commentStr}, " ")
 			} else {
-				log.Debug("got a head comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
+				yqlib.GetLogger().Debug("got a head comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
 				elem.n.HeadComment = joinComments([]string{elem.n.HeadComment, commentStr}, " ")
 			}
 
@@ -347,7 +348,7 @@ 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)
+		yqlib.GetLogger().Debug("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]
@@ -356,7 +357,7 @@ 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)
+		yqlib.GetLogger().Debug("got a foot comment for %v: [%v]", elem.label, commentStr)
 		elem.n.FootComment = joinComments([]string{elem.n.FootComment, commentStr}, " ")
 	}
 }

pkg/xml/encoder_xml.go

@@ -1,6 +1,6 @@
 //go:build !yq_noxml
 
-package yqlib
+package xml
 
 import (
 	"encoding/xml"
@@ -8,6 +8,8 @@ import (
 	"io"
 	"regexp"
 	"strings"
+
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
 )
 
 type xmlEncoder struct {
@@ -17,7 +19,7 @@ type xmlEncoder struct {
 	leadingContent string
 }
 
-func NewXMLEncoder(prefs XmlPreferences) Encoder {
+func NewXMLEncoder(prefs XmlPreferences) yqlib.Encoder {
 	var indentString = ""
 
 	for index := 0; index < prefs.Indent; index++ {
@@ -39,7 +41,7 @@ func (e *xmlEncoder) PrintLeadingContent(_ io.Writer, content string) error {
 	return nil
 }
 
-func (e *xmlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
+func (e *xmlEncoder) Encode(writer io.Writer, node *yqlib.CandidateNode) error {
 	encoder := xml.NewEncoder(writer)
 	// hack so we can manually add newlines to procInst and directives
 	e.writer = writer
@@ -59,7 +61,7 @@ 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)
+					yqlib.GetLogger().Warning("Unable to write newline, skipping: %w", err)
 				}
 			}
 		}
@@ -79,12 +81,12 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 	}
 
 	switch node.Kind {
-	case MappingNode:
+	case yqlib.MappingNode:
 		err := e.encodeTopLevelMap(encoder, node)
 		if err != nil {
 			return err
 		}
-	case ScalarNode:
+	case yqlib.ScalarNode:
 		var charData xml.CharData = []byte(node.Value)
 		err := encoder.EncodeToken(charData)
 		if err != nil {
@@ -99,8 +101,8 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 
 }
 
-func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *CandidateNode) error {
-	err := e.encodeComment(encoder, headAndLineComment(node))
+func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *yqlib.CandidateNode) error {
+	err := e.encodeComment(encoder, node.CleanHeadAndLineComment())
 	if err != nil {
 		return err
 	}
@@ -109,12 +111,12 @@ func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *CandidateNode
 		value := node.Content[i+1]
 
 		start := xml.StartElement{Name: xml.Name{Local: key.Value}}
-		log.Debugf("comments of key %v", key.Value)
-		err := e.encodeComment(encoder, headAndLineComment(key))
+		yqlib.GetLogger().Debugf("comments of key %v", key.Value)
+		err := e.encodeComment(encoder, key.CleanHeadAndLineComment())
 		if err != nil {
 			return err
 		}
-		if headAndLineComment(key) != "" {
+		if key.CleanHeadAndLineComment() != "" {
 			var newLine xml.CharData = []byte("\n")
 			err = encoder.EncodeToken(newLine)
 			if err != nil {
@@ -131,7 +133,7 @@ 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)
+				yqlib.GetLogger().Warning("Unable to write newline, skipping: %w", err)
 			}
 		} else if key.Value == e.prefs.DirectiveName {
 			var directive xml.Directive = []byte(value.Value)
@@ -139,48 +141,48 @@ 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)
+				yqlib.GetLogger().Warning("Unable to write newline, skipping: %w", err)
 			}
 		} else {
 
-			log.Debugf("recursing")
+			yqlib.GetLogger().Debugf("recursing")
 
 			err = e.doEncode(encoder, value, start)
 			if err != nil {
 				return err
 			}
 		}
-		err = e.encodeComment(encoder, footComment(key))
+		err = e.encodeComment(encoder, key.CleanFootComment())
 		if err != nil {
 			return err
 		}
 	}
-	return e.encodeComment(encoder, footComment(node))
+	return e.encodeComment(encoder, node.CleanFootComment())
 }
 
-func (e *xmlEncoder) encodeStart(encoder *xml.Encoder, node *CandidateNode, start xml.StartElement) error {
+func (e *xmlEncoder) encodeStart(encoder *xml.Encoder, node *yqlib.CandidateNode, start xml.StartElement) error {
 	err := encoder.EncodeToken(start)
 	if err != nil {
 		return err
 	}
-	return e.encodeComment(encoder, headComment(node))
+	return e.encodeComment(encoder, node.CleanHeadComment())
 }
 
-func (e *xmlEncoder) encodeEnd(encoder *xml.Encoder, node *CandidateNode, start xml.StartElement) error {
+func (e *xmlEncoder) encodeEnd(encoder *xml.Encoder, node *yqlib.CandidateNode, start xml.StartElement) error {
 	err := encoder.EncodeToken(start.End())
 	if err != nil {
 		return err
 	}
-	return e.encodeComment(encoder, footComment(node))
+	return e.encodeComment(encoder, node.CleanFootComment())
 }
 
-func (e *xmlEncoder) doEncode(encoder *xml.Encoder, node *CandidateNode, start xml.StartElement) error {
+func (e *xmlEncoder) doEncode(encoder *xml.Encoder, node *yqlib.CandidateNode, start xml.StartElement) error {
 	switch node.Kind {
-	case MappingNode:
+	case yqlib.MappingNode:
 		return e.encodeMap(encoder, node, start)
-	case SequenceNode:
+	case yqlib.SequenceNode:
 		return e.encodeArray(encoder, node, start)
-	case ScalarNode:
+	case yqlib.ScalarNode:
 		err := e.encodeStart(encoder, node, start)
 		if err != nil {
 			return err
@@ -192,7 +194,7 @@ func (e *xmlEncoder) doEncode(encoder *xml.Encoder, node *CandidateNode, start x
 			return err
 		}
 
-		if err = e.encodeComment(encoder, lineComment(node)); err != nil {
+		if err = e.encodeComment(encoder, node.CleanLineComment()); err != nil {
 			return err
 		}
 
@@ -207,13 +209,13 @@ var chompRegexp = regexp.MustCompile(`\n$`)
 
 func (e *xmlEncoder) encodeComment(encoder *xml.Encoder, commentStr string) error {
 	if commentStr != "" {
-		log.Debugf("got comment [%v]", commentStr)
+		yqlib.GetLogger().Debugf("got comment [%v]", commentStr)
 		// multi line string
 		if len(commentStr) > 2 && strings.Contains(commentStr[1:len(commentStr)-1], "\n") {
 			commentStr = chompRegexp.ReplaceAllString(commentStr, "")
-			log.Debugf("chompRegexp [%v]", commentStr)
+			yqlib.GetLogger().Debugf("chompRegexp [%v]", commentStr)
 			commentStr = xmlEncodeMultilineCommentRegex.ReplaceAllString(commentStr, "$1$2")
-			log.Debugf("processed multiline [%v]", commentStr)
+			yqlib.GetLogger().Debugf("processed multiline [%v]", commentStr)
 			// if the first line is non blank, add a space
 			if commentStr[0] != '\n' && commentStr[0] != ' ' {
 				commentStr = " " + commentStr
@@ -225,9 +227,9 @@ func (e *xmlEncoder) encodeComment(encoder *xml.Encoder, commentStr string) erro
 
 		if !strings.HasSuffix(commentStr, " ") && !strings.HasSuffix(commentStr, "\n") {
 			commentStr = commentStr + " "
-			log.Debugf("added suffix [%v]", commentStr)
+			yqlib.GetLogger().Debugf("added suffix [%v]", commentStr)
 		}
-		log.Debugf("encoding comment [%v]", commentStr)
+		yqlib.GetLogger().Debugf("encoding comment [%v]", commentStr)
 
 		var comment xml.Comment = []byte(commentStr)
 		err := encoder.EncodeToken(comment)
@@ -238,9 +240,9 @@ func (e *xmlEncoder) encodeComment(encoder *xml.Encoder, commentStr string) erro
 	return nil
 }
 
-func (e *xmlEncoder) encodeArray(encoder *xml.Encoder, node *CandidateNode, start xml.StartElement) error {
+func (e *xmlEncoder) encodeArray(encoder *xml.Encoder, node *yqlib.CandidateNode, start xml.StartElement) error {
 
-	if err := e.encodeComment(encoder, headAndLineComment(node)); err != nil {
+	if err := e.encodeComment(encoder, node.CleanHeadAndLineComment()); err != nil {
 		return err
 	}
 
@@ -250,7 +252,7 @@ func (e *xmlEncoder) encodeArray(encoder *xml.Encoder, node *CandidateNode, star
 			return err
 		}
 	}
-	return e.encodeComment(encoder, footComment(node))
+	return e.encodeComment(encoder, node.CleanFootComment())
 }
 
 func (e *xmlEncoder) isAttribute(name string) bool {
@@ -260,8 +262,8 @@ func (e *xmlEncoder) isAttribute(name string) bool {
 		!strings.HasPrefix(name, e.prefs.ProcInstPrefix)
 }
 
-func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start xml.StartElement) error {
-	log.Debug("its a map")
+func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *yqlib.CandidateNode, start xml.StartElement) error {
+	yqlib.GetLogger().Debug("its a map")
 
 	//first find all the attributes and put them on the start token
 	for i := 0; i < len(node.Content); i += 2 {
@@ -269,7 +271,7 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start
 		value := node.Content[i+1]
 
 		if e.isAttribute(key.Value) {
-			if value.Kind == ScalarNode {
+			if value.Kind == yqlib.ScalarNode {
 				attributeName := strings.Replace(key.Value, e.prefs.AttributePrefix, "", 1)
 				start.Attr = append(start.Attr, xml.Attr{Name: xml.Name{Local: attributeName}, Value: value.Value})
 			} else {
@@ -288,7 +290,7 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start
 		key := node.Content[i]
 		value := node.Content[i+1]
 
-		err := e.encodeComment(encoder, headAndLineComment(key))
+		err := e.encodeComment(encoder, key.CleanHeadAndLineComment())
 		if err != nil {
 			return err
 		}
@@ -305,7 +307,7 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start
 			}
 		} else if key.Value == e.prefs.ContentName {
 			// directly encode the contents
-			err = e.encodeComment(encoder, headAndLineComment(value))
+			err = e.encodeComment(encoder, value.CleanHeadAndLineComment())
 			if err != nil {
 				return err
 			}
@@ -314,7 +316,7 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start
 			if err != nil {
 				return err
 			}
-			err = e.encodeComment(encoder, footComment(value))
+			err = e.encodeComment(encoder, value.CleanFootComment())
 			if err != nil {
 				return err
 			}
@@ -325,7 +327,7 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *CandidateNode, start
 				return err
 			}
 		}
-		err = e.encodeComment(encoder, footComment(key))
+		err = e.encodeComment(encoder, key.CleanFootComment())
 		if err != nil {
 			return err
 		}

pkg/xml/xml.go

@@ -1,4 +1,6 @@
-package yqlib
+package xml
+
+import "github.com/mikefarah/yq/v4/pkg/yqlib"
 
 type XmlPreferences struct {
 	Indent          int
@@ -44,3 +46,27 @@ func (p *XmlPreferences) Copy() XmlPreferences {
 }
 
 var ConfiguredXMLPreferences = NewDefaultXmlPreferences()
+
+var XMLFormat = &yqlib.Format{"xml", []string{"x"}, "xml",
+	func() yqlib.Encoder { return NewXMLEncoder(ConfiguredXMLPreferences) },
+	func() yqlib.Decoder { return NewXMLDecoder(ConfiguredXMLPreferences) },
+	func(indent int) yqlib.Encoder {
+		prefs := ConfiguredXMLPreferences.Copy()
+		prefs.Indent = indent
+		return NewXMLEncoder(prefs)
+	},
+}
+
+var xmlYqRules = []*yqlib.ParticipleYqRule{
+	{"XMLEncodeWithIndent", `to_?xml\([0-9]+\)`, yqlib.CreateEncodeYqActionParsingIndent(XMLFormat), 0},
+	{"XmlDecode", `from_?xml|@xmld`, yqlib.CreateDecodeOpYqAction(XMLFormat), 0},
+	{"XMLEncode", `to_?xml`, yqlib.CreateEncodeOpYqAction(XMLFormat, 2), 0},
+	{"XMLEncodeNoIndent", `@xml`, yqlib.CreateEncodeOpYqAction(XMLFormat, 0), 0},
+	{"LoadXML", `load_?xml|xml_?load`, yqlib.CreateLoadOpYqAction(NewXMLDecoder(ConfiguredXMLPreferences)), 0},
+}
+
+func RegisterXmlFormat() {
+	yqlib.RegisterFormat(XMLFormat)
+	yqlib.RegisterRules(xmlYqRules)
+
+}

pkg/xml/xml_test.go

@@ -1,12 +1,13 @@
 //go:build !yq_noxml
 
-package yqlib
+package xml
 
 import (
 	"bufio"
 	"fmt"
 	"testing"
 
+	"github.com/mikefarah/yq/v4/pkg/yqlib"
 	"github.com/mikefarah/yq/v4/test"
 )
 
@@ -262,7 +263,7 @@ const expectedXmlWithProcInstAndDirectives = `<?xml version="1.0"?>
 </apple>
 `
 
-var xmlScenarios = []formatScenario{
+var xmlScenarios = []yqlib.FormatScenario{
 	{
 		skipDoc:     true,
 		description: "bad xml",
@@ -614,10 +615,10 @@ var xmlScenarios = []formatScenario{
 	},
 }
 
-func testXMLScenario(t *testing.T, s formatScenario) {
+func testXMLScenario(t *testing.T, s yqlib.FormatScenario) {
 	switch s.scenarioType {
 	case "", "decode":
-		yamlPrefs := ConfiguredYamlPreferences.Copy()
+		yamlPrefs := yqlib.ConfiguredYamlPreferences.Copy()
 		yamlPrefs.Indent = 4
 		test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewXMLDecoder(ConfiguredXMLPreferences), NewYamlEncoder(yamlPrefs)), s.description)
 	case "encode":
@@ -661,7 +662,7 @@ func testXMLScenario(t *testing.T, s formatScenario) {
 }
 
 func documentXMLScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 
 	if s.skipDoc {
 		return
@@ -685,7 +686,7 @@ func documentXMLScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
 	}
 }
 
-func documentXMLDecodeScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLDecodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -707,7 +708,7 @@ func documentXMLDecodeScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewXMLDecoder(ConfiguredXMLPreferences), NewYamlEncoder(ConfiguredYamlPreferences))))
 }
 
-func documentXMLDecodeKeepNsScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLDecodeKeepNsScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -731,7 +732,7 @@ func documentXMLDecodeKeepNsScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```xml\n%v```\n\n", mustProcessFormatScenario(s, NewXMLDecoder(prefsWithout), NewXMLEncoder(prefsWithout))))
 }
 
-func documentXMLDecodeKeepNsRawTokenScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLDecodeKeepNsRawTokenScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -758,7 +759,7 @@ func documentXMLDecodeKeepNsRawTokenScenario(w *bufio.Writer, s formatScenario)
 	writeOrPanic(w, fmt.Sprintf("```xml\n%v```\n\n", mustProcessFormatScenario(s, NewXMLDecoder(prefsWithout), NewXMLEncoder(prefsWithout))))
 }
 
-func documentXMLEncodeScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLEncodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -776,7 +777,7 @@ func documentXMLEncodeScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```xml\n%v```\n\n", mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewXMLEncoder(ConfiguredXMLPreferences))))
 }
 
-func documentXMLRoundTripScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLRoundTripScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -794,7 +795,7 @@ func documentXMLRoundTripScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```xml\n%v```\n\n", mustProcessFormatScenario(s, NewXMLDecoder(ConfiguredXMLPreferences), NewXMLEncoder(ConfiguredXMLPreferences))))
 }
 
-func documentXMLSkipDirectivesScenario(w *bufio.Writer, s formatScenario) {
+func documentXMLSkipDirectivesScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {

pkg/yqlib/all_at_once_evaluator.go

@@ -63,7 +63,7 @@ func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string
 	}
 
 	if allDocuments.Len() == 0 {
-		candidateNode := createScalarNode(nil, "")
+		candidateNode := CreateScalarNode(nil, "")
 		allDocuments.PushBack(candidateNode)
 	}
 

pkg/yqlib/candidate_node.go

@@ -27,14 +27,14 @@ const (
 	FlowStyle
 )
 
-func createStringScalarNode(stringValue string) *CandidateNode {
+func CreateStringScalarNode(stringValue string) *CandidateNode {
 	var node = &CandidateNode{Kind: ScalarNode}
 	node.Value = stringValue
 	node.Tag = "!!str"
 	return node
 }
 
-func createScalarNode(value interface{}, stringValue string) *CandidateNode {
+func CreateScalarNode(value interface{}, stringValue string) *CandidateNode {
 	var node = &CandidateNode{Kind: ScalarNode}
 	node.Value = stringValue
 
@@ -219,7 +219,7 @@ func (n *CandidateNode) AddChild(rawChild *CandidateNode) {
 		value.Key.SetParent(n)
 	} else {
 		index := len(n.Content)
-		keyNode := createScalarNode(index, fmt.Sprintf("%v", index))
+		keyNode := CreateScalarNode(index, fmt.Sprintf("%v", index))
 		keyNode.SetParent(n)
 		value.Key = keyNode
 	}
@@ -243,7 +243,7 @@ func (n *CandidateNode) AddChildren(children []*CandidateNode) {
 
 func (n *CandidateNode) GetValueRep() (interface{}, error) {
 	log.Debugf("GetValueRep for %v value: %v", n.GetNicePath(), n.Value)
-	realTag := n.guessTagFromCustomType()
+	realTag := n.GuessTagFromCustomType()
 
 	switch realTag {
 	case "!!int":
@@ -261,17 +261,17 @@ func (n *CandidateNode) GetValueRep() (interface{}, error) {
 	return n.Value, nil
 }
 
-func (n *CandidateNode) guessTagFromCustomType() string {
+func (n *CandidateNode) GuessTagFromCustomType() string {
 	if strings.HasPrefix(n.Tag, "!!") {
 		return n.Tag
 	} else if n.Value == "" {
-		log.Debug("guessTagFromCustomType: node has no value to guess the type with")
+		log.Debug("GuessTagFromCustomType: node has no value to guess the type with")
 		return n.Tag
 	}
 	dataBucket, errorReading := parseSnippet(n.Value)
 
 	if errorReading != nil {
-		log.Debug("guessTagFromCustomType: could not guess underlying tag type %v", errorReading)
+		log.Debug("GuessTagFromCustomType: could not guess underlying tag type %v", errorReading)
 		return n.Tag
 	}
 	guessedTag := dataBucket.Tag
@@ -376,7 +376,7 @@ func (n *CandidateNode) UpdateFrom(other *CandidateNode, prefs assignPreferences
 	// if this is an empty map or empty array, use the style of other node.
 	if (n.Kind != ScalarNode && len(n.Content) == 0) ||
 		// if the tag has changed (e.g. from str to bool)
-		(n.guessTagFromCustomType() != other.guessTagFromCustomType()) {
+		(n.GuessTagFromCustomType() != other.GuessTagFromCustomType()) {
 		n.Style = other.Style
 	}
 
@@ -428,3 +428,34 @@ func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode, prefs assignP
 		n.LineComment = other.LineComment
 	}
 }
+
+func (n *CandidateNode) CleanHeadAndLineComment() string {
+	return n.CleanHeadComment() + n.CleanLineComment()
+}
+
+func (n *CandidateNode) CleanHeadComment() string {
+	return strings.Replace(n.HeadComment, "#", "", 1)
+}
+
+func (n *CandidateNode) CleanLineComment() string {
+	return strings.Replace(n.LineComment, "#", "", 1)
+}
+
+func (n *CandidateNode) CleanFootComment() string {
+	return strings.Replace(n.FootComment, "#", "", 1)
+}
+
+func (n *CandidateNode) ConvertKeysToStrings() {
+
+	if n.Kind == MappingNode {
+		for index, child := range n.Content {
+			if index%2 == 0 { // its a map key
+				child.Tag = "!!str"
+			}
+		}
+	}
+
+	for _, child := range n.Content {
+		child.ConvertKeysToStrings()
+	}
+}

pkg/yqlib/candidate_node_test.go

@@ -64,13 +64,13 @@ func TestCandidateNodeChildWhenParentUpdated(t *testing.T) {
 	test.AssertResultWithContext(t, uint(1), child.GetDocument(), "document index")
 }
 
-type createScalarNodeScenario struct {
+type CreateScalarNodeScenario struct {
 	value       interface{}
 	stringValue string
 	expectedTag string
 }
 
-var createScalarScenarios = []createScalarNodeScenario{
+var createScalarScenarios = []CreateScalarNodeScenario{
 	{
 		value:       "mike",
 		stringValue: "mike",
@@ -100,20 +100,20 @@ var createScalarScenarios = []createScalarNodeScenario{
 
 func TestCreateScalarNodeScenarios(t *testing.T) {
 	for _, tt := range createScalarScenarios {
-		actual := createScalarNode(tt.value, tt.stringValue)
+		actual := CreateScalarNode(tt.value, tt.stringValue)
 		test.AssertResultWithContext(t, tt.stringValue, actual.Value, fmt.Sprintf("Value for: Value: [%v], String: %v", tt.value, tt.stringValue))
 		test.AssertResultWithContext(t, tt.expectedTag, actual.Tag, fmt.Sprintf("Value for: Value: [%v], String: %v", tt.value, tt.stringValue))
 	}
 }
 
 func TestGetKeyForMapValue(t *testing.T) {
-	key := createStringScalarNode("yourKey")
+	key := CreateStringScalarNode("yourKey")
 	n := CandidateNode{Key: key, Value: "meow", document: 3}
 	test.AssertResult(t, "3 - yourKey", n.GetKey())
 }
 
 func TestGetKeyForMapKey(t *testing.T) {
-	key := createStringScalarNode("yourKey")
+	key := CreateStringScalarNode("yourKey")
 	key.IsMapKey = true
 	key.document = 3
 	test.AssertResult(t, "key-yourKey-3 - ", key.GetKey())
@@ -125,7 +125,7 @@ func TestGetKeyForValue(t *testing.T) {
 }
 
 func TestGetParsedKeyForMapKey(t *testing.T) {
-	key := createStringScalarNode("yourKey")
+	key := CreateStringScalarNode("yourKey")
 	key.IsMapKey = true
 	key.document = 3
 	test.AssertResult(t, "yourKey", key.getParsedKey())
@@ -137,13 +137,13 @@ func TestGetParsedKeyForLooseValue(t *testing.T) {
 }
 
 func TestGetParsedKeyForMapValue(t *testing.T) {
-	key := createStringScalarNode("yourKey")
+	key := CreateStringScalarNode("yourKey")
 	n := CandidateNode{Key: key, Value: "meow", document: 3}
 	test.AssertResult(t, "yourKey", n.getParsedKey())
 }
 
 func TestGetParsedKeyForArrayValue(t *testing.T) {
-	key := createScalarNode(4, "4")
+	key := CreateScalarNode(4, "4")
 	n := CandidateNode{Key: key, Value: "meow", document: 3}
 	test.AssertResult(t, 4, n.getParsedKey())
 }

pkg/yqlib/candidiate_node_json.go

@@ -96,7 +96,7 @@ func (o *CandidateNode) UnmarshalJSON(data []byte) error {
 
 			if child == nil {
 				// need to represent it as a null scalar
-				child = createScalarNode(nil, "null")
+				child = CreateScalarNode(nil, "null")
 			}
 			childKey := o.CreateChild()
 			childKey.Kind = ScalarNode

pkg/yqlib/csv_test.go

@@ -94,7 +94,7 @@ const tsvTestExpectedSimpleCsv = `i	like	csv
 because	excel	is	cool
 `
 
-var csvScenarios = []formatScenario{
+var csvScenarios = []FormatScenario{
 	{
 		description:  "Encode CSV simple",
 		input:        csvTestSimpleYaml,
@@ -210,7 +210,7 @@ var csvScenarios = []formatScenario{
 	},
 }
 
-func testCSVScenario(t *testing.T, s formatScenario) {
+func testCSVScenario(t *testing.T, s FormatScenario) {
 	switch s.scenarioType {
 	case "encode-csv":
 		test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewCsvEncoder(ConfiguredCsvPreferences)), s.description)
@@ -229,7 +229,7 @@ func testCSVScenario(t *testing.T, s formatScenario) {
 	}
 }
 
-func documentCSVDecodeObjectScenario(w *bufio.Writer, s formatScenario, formatType string) {
+func documentCSVDecodeObjectScenario(w *bufio.Writer, s FormatScenario, formatType string) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -254,7 +254,7 @@ func documentCSVDecodeObjectScenario(w *bufio.Writer, s formatScenario, formatTy
 	)
 }
 
-func documentCSVDecodeObjectNoAutoScenario(w *bufio.Writer, s formatScenario, formatType string) {
+func documentCSVDecodeObjectNoAutoScenario(w *bufio.Writer, s FormatScenario, formatType string) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -279,7 +279,7 @@ func documentCSVDecodeObjectNoAutoScenario(w *bufio.Writer, s formatScenario, fo
 	)
 }
 
-func documentCSVEncodeScenario(w *bufio.Writer, s formatScenario, formatType string) {
+func documentCSVEncodeScenario(w *bufio.Writer, s FormatScenario, formatType string) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -312,7 +312,7 @@ func documentCSVEncodeScenario(w *bufio.Writer, s formatScenario, formatType str
 	)
 }
 
-func documentCSVRoundTripScenario(w *bufio.Writer, s formatScenario, formatType string) {
+func documentCSVRoundTripScenario(w *bufio.Writer, s FormatScenario, formatType string) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -348,7 +348,7 @@ func documentCSVRoundTripScenario(w *bufio.Writer, s formatScenario, formatType
 }
 
 func documentCSVScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 	if s.skipDoc {
 		return
 	}

pkg/yqlib/data_tree_navigator.go

@@ -13,6 +13,7 @@ type DataTreeNavigator interface {
 	GetMatchingNodes(context Context, expressionNode *ExpressionNode) (Context, error)
 
 	DeeplyAssign(context Context, path []interface{}, rhsNode *CandidateNode) error
+	DeeplyAssignKey(context Context, path []interface{}, rhsNode *CandidateNode) error
 }
 
 type dataTreeNavigator struct {
@@ -23,6 +24,14 @@ func NewDataTreeNavigator() DataTreeNavigator {
 }
 
 func (d *dataTreeNavigator) DeeplyAssign(context Context, path []interface{}, rhsCandidateNode *CandidateNode) error {
+	return d.deeplyAssign(context, path, rhsCandidateNode, false)
+}
+
+func (d *dataTreeNavigator) DeeplyAssignKey(context Context, path []interface{}, rhsCandidateNode *CandidateNode) error {
+	return d.deeplyAssign(context, path, rhsCandidateNode, true)
+}
+
+func (d *dataTreeNavigator) deeplyAssign(context Context, path []interface{}, rhsCandidateNode *CandidateNode, targetKey bool) error {
 
 	assignmentOp := &Operation{OperationType: assignOpType, Preferences: assignPreferences{}}
 
@@ -41,7 +50,7 @@ func (d *dataTreeNavigator) DeeplyAssign(context Context, path []interface{}, rh
 
 	assignmentOpNode := &ExpressionNode{
 		Operation: assignmentOp,
-		LHS:       createTraversalTree(path, traversePreferences{}, false),
+		LHS:       createTraversalTree(path, traversePreferences{}, targetKey),
 		RHS:       &ExpressionNode{Operation: rhsOp},
 	}
 

pkg/yqlib/decoder_base64.go

@@ -68,5 +68,5 @@ func (dec *base64Decoder) Decode() (*CandidateNode, error) {
 		}
 	}
 	dec.readAnything = true
-	return createStringScalarNode(buf.String()), nil
+	return CreateStringScalarNode(buf.String()), nil
 }

pkg/yqlib/decoder_csv_object.go

@@ -32,7 +32,7 @@ func (dec *csvObjectDecoder) convertToNode(content string) *CandidateNode {
 	// if we're not auto-parsing, then we wont put in parsed objects or arrays
 	// but we still parse scalars
 	if err != nil || (!dec.prefs.AutoParse && node.Kind != ScalarNode) {
-		return createScalarNode(content, content)
+		return CreateScalarNode(content, content)
 	}
 	return node
 }
@@ -41,7 +41,7 @@ func (dec *csvObjectDecoder) createObject(headerRow []string, contentRow []strin
 	objectNode := &CandidateNode{Kind: MappingNode, Tag: "!!map"}
 
 	for i, header := range headerRow {
-		objectNode.AddKeyValueChild(createScalarNode(header, header), dec.convertToNode(contentRow[i]))
+		objectNode.AddKeyValueChild(CreateScalarNode(header, header), dec.convertToNode(contentRow[i]))
 	}
 	return objectNode
 }

pkg/yqlib/decoder_test.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-type formatScenario struct {
+type FormatScenario struct {
 	input          string
 	indent         int
 	expression     string
@@ -19,7 +19,7 @@ type formatScenario struct {
 	expectedError  string
 }
 
-func processFormatScenario(s formatScenario, decoder Decoder, encoder Encoder) (string, error) {
+func processFormatScenario(s FormatScenario, decoder Decoder, encoder Encoder) (string, error) {
 	var output bytes.Buffer
 	writer := bufio.NewWriter(&output)
 
@@ -64,7 +64,7 @@ func processFormatScenario(s formatScenario, decoder Decoder, encoder Encoder) (
 	return output.String(), nil
 }
 
-func mustProcessFormatScenario(s formatScenario, decoder Decoder, encoder Encoder) string {
+func mustProcessFormatScenario(s FormatScenario, decoder Decoder, encoder Encoder) string {
 
 	result, err := processFormatScenario(s, decoder, encoder)
 	if err != nil {

pkg/yqlib/decoder_toml.go

@@ -145,30 +145,30 @@ func (dec *tomlDecoder) createArray(tomlNode *toml.Node) (*CandidateNode, error)
 
 func (dec *tomlDecoder) createStringScalar(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := string(tomlNode.Data)
-	return createScalarNode(content, content), nil
+	return CreateScalarNode(content, content), nil
 }
 
 func (dec *tomlDecoder) createBoolScalar(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := string(tomlNode.Data)
-	return createScalarNode(content == "true", content), nil
+	return CreateScalarNode(content == "true", content), nil
 }
 
 func (dec *tomlDecoder) createIntegerScalar(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := string(tomlNode.Data)
 	_, num, err := parseInt64(content)
-	return createScalarNode(num, content), err
+	return CreateScalarNode(num, content), err
 }
 
 func (dec *tomlDecoder) createDateTimeScalar(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := string(tomlNode.Data)
 	val, err := parseDateTime(time.RFC3339, content)
-	return createScalarNode(val, content), err
+	return CreateScalarNode(val, content), err
 }
 
 func (dec *tomlDecoder) createFloatScalar(tomlNode *toml.Node) (*CandidateNode, error) {
 	content := string(tomlNode.Data)
 	num, err := strconv.ParseFloat(content, 64)
-	return createScalarNode(num, content), err
+	return CreateScalarNode(num, content), err
 }
 
 func (dec *tomlDecoder) decodeNode(tomlNode *toml.Node) (*CandidateNode, error) {

pkg/yqlib/decoder_uri.go

@@ -48,5 +48,5 @@ func (dec *uriDecoder) Decode() (*CandidateNode, error) {
 		return nil, err
 	}
 	dec.readAnything = true
-	return createStringScalarNode(newValue), nil
+	return CreateStringScalarNode(newValue), nil
 }

pkg/yqlib/decoder_yaml.go

@@ -151,7 +151,7 @@ func (dec *yamlDecoder) Decode() (*CandidateNode, error) {
 }
 
 func (dec *yamlDecoder) blankNodeWithComment() *CandidateNode {
-	node := createScalarNode(nil, "")
+	node := CreateScalarNode(nil, "")
 	node.LeadingContent = dec.leadingContent
 	return node
 }

pkg/yqlib/encoder.go

@@ -10,18 +10,3 @@ type Encoder interface {
 	PrintLeadingContent(writer io.Writer, content string) error
 	CanHandleAliases() bool
 }
-
-func mapKeysToStrings(node *CandidateNode) {
-
-	if node.Kind == MappingNode {
-		for index, child := range node.Content {
-			if index%2 == 0 { // its a map key
-				child.Tag = "!!str"
-			}
-		}
-	}
-
-	for _, child := range node.Content {
-		mapKeysToStrings(child)
-	}
-}

pkg/yqlib/encoder_base64.go

@@ -27,7 +27,7 @@ func (e *base64Encoder) PrintLeadingContent(_ io.Writer, _ string) error {
 }
 
 func (e *base64Encoder) Encode(writer io.Writer, node *CandidateNode) error {
-	if node.guessTagFromCustomType() != "!!str" {
+	if node.GuessTagFromCustomType() != "!!str" {
 		return fmt.Errorf("cannot encode %v as base64, can only operate on strings", node.Tag)
 	}
 	_, err := writer.Write([]byte(e.encoding.EncodeToString([]byte(node.Value))))

pkg/yqlib/encoder_csv.go

@@ -65,7 +65,7 @@ func (e *csvEncoder) createChildRow(child *CandidateNode, headers []*CandidateNo
 	childRow := make([]*CandidateNode, 0)
 	for _, header := range headers {
 		keyIndex := findKeyInMap(child, header)
-		value := createScalarNode(nil, "")
+		value := CreateScalarNode(nil, "")
 		if keyIndex != -1 {
 			value = child.Content[keyIndex+1]
 		}
@@ -102,7 +102,7 @@ func (e *csvEncoder) encodeObjects(csvWriter *csv.Writer, content []*CandidateNo
 
 func (e *csvEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 	if node.Kind == ScalarNode {
-		return writeString(writer, node.Value+"\n")
+		return WriteString(writer, node.Value+"\n")
 	}
 
 	csvWriter := csv.NewWriter(writer)

pkg/yqlib/encoder_json.go

@@ -41,7 +41,7 @@ func (je *jsonEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 	log.Debugf("kids %v", len(node.Content))
 
 	if node.Kind == ScalarNode && je.prefs.UnwrapScalar {
-		return writeString(writer, node.Value+"\n")
+		return WriteString(writer, node.Value+"\n")
 	}
 
 	destination := writer

pkg/yqlib/encoder_lua.go

@@ -86,15 +86,15 @@ func (le *luaEncoder) encodeString(writer io.Writer, node *CandidateNode) error
 	case LiteralStyle, FoldedStyle, FlowStyle:
 		for i := 0; i < 10; i++ {
 			if !strings.Contains(node.Value, "]"+strings.Repeat("=", i)+"]") {
-				err := writeString(writer, "["+strings.Repeat("=", i)+"[\n")
+				err := WriteString(writer, "["+strings.Repeat("=", i)+"[\n")
 				if err != nil {
 					return err
 				}
-				err = writeString(writer, node.Value)
+				err = WriteString(writer, node.Value)
 				if err != nil {
 					return err
 				}
-				return writeString(writer, "]"+strings.Repeat("=", i)+"]")
+				return WriteString(writer, "]"+strings.Repeat("=", i)+"]")
 			}
 		}
 	case SingleQuotedStyle:
@@ -102,22 +102,22 @@ func (le *luaEncoder) encodeString(writer io.Writer, node *CandidateNode) error
 
 		// fallthrough to regular ol' string
 	}
-	return writeString(writer, quote+le.escape.Replace(node.Value)+quote)
+	return WriteString(writer, quote+le.escape.Replace(node.Value)+quote)
 }
 
 func (le *luaEncoder) writeIndent(writer io.Writer) error {
 	if le.indentStr == "" {
 		return nil
 	}
-	err := writeString(writer, "\n")
+	err := WriteString(writer, "\n")
 	if err != nil {
 		return err
 	}
-	return writeString(writer, strings.Repeat(le.indentStr, le.indent))
+	return WriteString(writer, strings.Repeat(le.indentStr, le.indent))
 }
 
 func (le *luaEncoder) encodeArray(writer io.Writer, node *CandidateNode) error {
-	err := writeString(writer, "{")
+	err := WriteString(writer, "{")
 	if err != nil {
 		return err
 	}
@@ -131,13 +131,13 @@ func (le *luaEncoder) encodeArray(writer io.Writer, node *CandidateNode) error {
 		if err != nil {
 			return err
 		}
-		err = writeString(writer, ",")
+		err = WriteString(writer, ",")
 		if err != nil {
 			return err
 		}
 		if child.LineComment != "" {
 			sansPrefix, _ := strings.CutPrefix(child.LineComment, "#")
-			err = writeString(writer, " --"+sansPrefix)
+			err = WriteString(writer, " --"+sansPrefix)
 			if err != nil {
 				return err
 			}
@@ -150,7 +150,7 @@ func (le *luaEncoder) encodeArray(writer io.Writer, node *CandidateNode) error {
 			return err
 		}
 	}
-	return writeString(writer, "}")
+	return WriteString(writer, "}")
 }
 
 func needsQuoting(s string) bool {
@@ -181,7 +181,7 @@ func needsQuoting(s string) bool {
 
 func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bool) error {
 	if !global {
-		err := writeString(writer, "{")
+		err := WriteString(writer, "{")
 		if err != nil {
 			return err
 		}
@@ -194,7 +194,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 			if err != nil {
 				return err
 			}
-			err = writeString(writer, ";")
+			err = WriteString(writer, ";")
 			if err != nil {
 				return err
 			}
@@ -207,19 +207,19 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 				}
 			}
 			if (le.unquoted || global) && child.Tag == "!!str" && !needsQuoting(child.Value) {
-				err := writeString(writer, child.Value+" = ")
+				err := WriteString(writer, child.Value+" = ")
 				if err != nil {
 					return err
 				}
 			} else {
 				if global {
 					// This only works in Lua 5.2+
-					err := writeString(writer, "_ENV")
+					err := WriteString(writer, "_ENV")
 					if err != nil {
 						return err
 					}
 				}
-				err := writeString(writer, "[")
+				err := WriteString(writer, "[")
 				if err != nil {
 					return err
 				}
@@ -227,7 +227,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 				if err != nil {
 					return err
 				}
-				err = writeString(writer, "] = ")
+				err = WriteString(writer, "] = ")
 				if err != nil {
 					return err
 				}
@@ -235,7 +235,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 		}
 		if child.LineComment != "" {
 			sansPrefix, _ := strings.CutPrefix(child.LineComment, "#")
-			err := writeString(writer, strings.Repeat(" ", i%2)+"--"+sansPrefix)
+			err := WriteString(writer, strings.Repeat(" ", i%2)+"--"+sansPrefix)
 			if err != nil {
 				return err
 			}
@@ -249,7 +249,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 		}
 	}
 	if global {
-		return writeString(writer, "\n")
+		return WriteString(writer, "\n")
 	}
 	le.indent--
 	if len(node.Content) != 0 {
@@ -258,7 +258,7 @@ func (le *luaEncoder) encodeMap(writer io.Writer, node *CandidateNode, global bo
 			return err
 		}
 	}
-	return writeString(writer, "}")
+	return WriteString(writer, "}")
 }
 
 func (le *luaEncoder) encodeAny(writer io.Writer, node *CandidateNode) error {
@@ -273,30 +273,30 @@ func (le *luaEncoder) encodeAny(writer io.Writer, node *CandidateNode) error {
 			return le.encodeString(writer, node)
 		case "!!null":
 			// TODO reject invalid use as a table key
-			return writeString(writer, "nil")
+			return WriteString(writer, "nil")
 		case "!!bool":
 			// Yaml 1.2 has case variation e.g. True, FALSE etc but Lua only has
 			// lower case
-			return writeString(writer, strings.ToLower(node.Value))
+			return WriteString(writer, strings.ToLower(node.Value))
 		case "!!int":
 			if strings.HasPrefix(node.Value, "0o") {
 				_, octalValue, err := parseInt64(node.Value)
 				if err != nil {
 					return err
 				}
-				return writeString(writer, fmt.Sprintf("%d", octalValue))
+				return WriteString(writer, fmt.Sprintf("%d", octalValue))
 			}
-			return writeString(writer, strings.ToLower(node.Value))
+			return WriteString(writer, strings.ToLower(node.Value))
 		case "!!float":
 			switch strings.ToLower(node.Value) {
 			case ".inf", "+.inf":
-				return writeString(writer, "(1/0)")
+				return WriteString(writer, "(1/0)")
 			case "-.inf":
-				return writeString(writer, "(-1/0)")
+				return WriteString(writer, "(-1/0)")
 			case ".nan":
-				return writeString(writer, "(0/0)")
+				return WriteString(writer, "(0/0)")
 			default:
-				return writeString(writer, node.Value)
+				return WriteString(writer, node.Value)
 			}
 		default:
 			return fmt.Errorf("Lua encoder NYI -- %s", node.Tag)
@@ -307,7 +307,7 @@ func (le *luaEncoder) encodeAny(writer io.Writer, node *CandidateNode) error {
 }
 
 func (le *luaEncoder) encodeTopLevel(writer io.Writer, node *CandidateNode) error {
-	err := writeString(writer, le.docPrefix)
+	err := WriteString(writer, le.docPrefix)
 	if err != nil {
 		return err
 	}
@@ -315,7 +315,7 @@ func (le *luaEncoder) encodeTopLevel(writer io.Writer, node *CandidateNode) erro
 	if err != nil {
 		return err
 	}
-	return writeString(writer, le.docSuffix)
+	return WriteString(writer, le.docSuffix)
 }
 
 func (le *luaEncoder) Encode(writer io.Writer, node *CandidateNode) error {

pkg/yqlib/encoder_sh.go

@@ -30,11 +30,11 @@ func (e *shEncoder) PrintLeadingContent(_ io.Writer, _ string) error {
 }
 
 func (e *shEncoder) Encode(writer io.Writer, node *CandidateNode) error {
-	if node.guessTagFromCustomType() != "!!str" {
+	if node.GuessTagFromCustomType() != "!!str" {
 		return fmt.Errorf("cannot encode %v as URI, can only operate on strings. Please first pipe through another encoding operator to convert the value to a string", node.Tag)
 	}
 
-	return writeString(writer, e.encode(node.Value))
+	return WriteString(writer, e.encode(node.Value))
 }
 
 // put any (shell-unsafe) characters into a single-quoted block, close the block lazily

pkg/yqlib/encoder_shellvariables.go

@@ -30,7 +30,7 @@ func (pe *shellVariablesEncoder) PrintLeadingContent(_ io.Writer, _ string) erro
 
 func (pe *shellVariablesEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 
-	mapKeysToStrings(node)
+	node.ConvertKeysToStrings()
 	err := pe.doEncode(&writer, node, "")
 	if err != nil {
 		return err

pkg/yqlib/encoder_toml.go

@@ -14,7 +14,7 @@ func NewTomlEncoder() Encoder {
 
 func (te *tomlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 	if node.Kind == ScalarNode {
-		return writeString(writer, node.Value+"\n")
+		return WriteString(writer, node.Value+"\n")
 	}
 	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")
 }

pkg/yqlib/encoder_uri.go

@@ -26,7 +26,7 @@ func (e *uriEncoder) PrintLeadingContent(_ io.Writer, _ string) error {
 }
 
 func (e *uriEncoder) Encode(writer io.Writer, node *CandidateNode) error {
-	if node.guessTagFromCustomType() != "!!str" {
+	if node.GuessTagFromCustomType() != "!!str" {
 		return fmt.Errorf("cannot encode %v as URI, can only operate on strings. Please first pipe through another encoding operator to convert the value to a string", node.Tag)
 	}
 	_, err := writer.Write([]byte(url.QueryEscape(node.Value)))

pkg/yqlib/encoder_yaml.go

@@ -26,7 +26,7 @@ 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 {
+		if err := WriteString(writer, "---\n"); err != nil {
 			return err
 		}
 	}
@@ -54,7 +54,7 @@ func (ye *yamlEncoder) PrintLeadingContent(writer io.Writer, content string) err
 			if len(readline) > 0 && readline != "\n" && readline[0] != '%' && !commentLineRegEx.MatchString(readline) {
 				readline = "# " + readline
 			}
-			if err := writeString(writer, readline); err != nil {
+			if err := WriteString(writer, readline); err != nil {
 				return err
 			}
 		}
@@ -62,7 +62,7 @@ func (ye *yamlEncoder) PrintLeadingContent(writer io.Writer, content string) 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 {
+				if err := WriteString(writer, "\n"); err != nil {
 					return err
 				}
 			}
@@ -80,7 +80,7 @@ func (ye *yamlEncoder) Encode(writer io.Writer, node *CandidateNode) error {
 		if node.LeadingContent == "" || valueToPrint != "" {
 			valueToPrint = valueToPrint + "\n"
 		}
-		return writeString(writer, valueToPrint)
+		return WriteString(writer, valueToPrint)
 	}
 
 	destination := writer

pkg/yqlib/format.go

@@ -6,82 +6,100 @@ import (
 )
 
 type EncoderFactoryFunction func() Encoder
+type InDocumentEncoderFactoryFunction func(indent int) Encoder
 type DecoderFactoryFunction func() Decoder
 
 type Format struct {
-	FormalName     string
-	Names          []string
-	EncoderFactory EncoderFactoryFunction
-	DecoderFactory DecoderFactoryFunction
+	FormalName       string
+	Names            []string
+	DefaultExtension string
+	EncoderFactory   EncoderFactoryFunction
+	DecoderFactory   DecoderFactoryFunction
+
+	/**
+	* Like the Encoder Factory, but for encoding content within the document itself.
+	* Should turn off colors and other settings to ensure the content comes out right.
+	* If this function is not configured, it will default to the EncoderFactory.
+	**/
+	InDocumentEncoderFactory InDocumentEncoderFactoryFunction
 }
 
-var YamlFormat = &Format{"yaml", []string{"y", "yml"},
+var YamlFormat = &Format{"yaml", []string{"y", "yml"}, "yml",
 	func() Encoder { return NewYamlEncoder(ConfiguredYamlPreferences) },
 	func() Decoder { return NewYamlDecoder(ConfiguredYamlPreferences) },
+	func(indent int) Encoder {
+		prefs := ConfiguredYamlPreferences.Copy()
+		prefs.Indent = indent
+		prefs.ColorsEnabled = false
+		return NewYamlEncoder(prefs)
+	},
 }
 
-var JSONFormat = &Format{"json", []string{"j"},
+var JSONFormat = &Format{"json", []string{"j"}, "json",
 	func() Encoder { return NewJSONEncoder(ConfiguredJSONPreferences) },
 	func() Decoder { return NewJSONDecoder() },
+	func(indent int) Encoder {
+		prefs := ConfiguredJSONPreferences.Copy()
+		prefs.Indent = indent
+		prefs.ColorsEnabled = false
+		prefs.UnwrapScalar = false
+		return NewJSONEncoder(prefs)
+	},
 }
 
-var PropertiesFormat = &Format{"props", []string{"p", "properties"},
-	func() Encoder { return NewPropertiesEncoder(ConfiguredPropertiesPreferences) },
-	func() Decoder { return NewPropertiesDecoder() },
-}
-
-var CSVFormat = &Format{"csv", []string{"c"},
+var CSVFormat = &Format{"csv", []string{"c"}, "csv",
 	func() Encoder { return NewCsvEncoder(ConfiguredCsvPreferences) },
 	func() Decoder { return NewCSVObjectDecoder(ConfiguredCsvPreferences) },
+	nil,
 }
 
-var TSVFormat = &Format{"tsv", []string{"t"},
+var TSVFormat = &Format{"tsv", []string{"t"}, "tsv",
 	func() Encoder { return NewCsvEncoder(ConfiguredTsvPreferences) },
 	func() Decoder { return NewCSVObjectDecoder(ConfiguredTsvPreferences) },
+	nil,
 }
 
-var XMLFormat = &Format{"xml", []string{"x"},
-	func() Encoder { return NewXMLEncoder(ConfiguredXMLPreferences) },
-	func() Decoder { return NewXMLDecoder(ConfiguredXMLPreferences) },
-}
-
-var Base64Format = &Format{"base64", []string{},
+var Base64Format = &Format{"base64", []string{}, "txt",
 	func() Encoder { return NewBase64Encoder() },
 	func() Decoder { return NewBase64Decoder() },
+	nil,
 }
 
-var UriFormat = &Format{"uri", []string{},
+var UriFormat = &Format{"uri", []string{}, "txt",
 	func() Encoder { return NewUriEncoder() },
 	func() Decoder { return NewUriDecoder() },
+	nil,
 }
 
-var ShFormat = &Format{"", nil,
+var ShFormat = &Format{"", nil, "sh",
 	func() Encoder { return NewShEncoder() },
 	nil,
-}
-
-var TomlFormat = &Format{"toml", []string{},
-	func() Encoder { return NewTomlEncoder() },
-	func() Decoder { return NewTomlDecoder() },
-}
-
-var ShellVariablesFormat = &Format{"shell", []string{"s", "sh"},
-	func() Encoder { return NewShellVariablesEncoder() },
 	nil,
 }
 
-var LuaFormat = &Format{"lua", []string{"l"},
+var TomlFormat = &Format{"toml", []string{}, "toml",
+	func() Encoder { return NewTomlEncoder() },
+	func() Decoder { return NewTomlDecoder() },
+	nil,
+}
+
+var ShellVariablesFormat = &Format{"shell", []string{"s", "sh"}, "sh",
+	func() Encoder { return NewShellVariablesEncoder() },
+	nil,
+	nil,
+}
+
+var LuaFormat = &Format{"lua", []string{"l"}, "lua",
 	func() Encoder { return NewLuaEncoder(ConfiguredLuaPreferences) },
 	func() Decoder { return NewLuaDecoder(ConfiguredLuaPreferences) },
+	nil,
 }
 
 var Formats = []*Format{
 	YamlFormat,
 	JSONFormat,
-	PropertiesFormat,
 	CSVFormat,
 	TSVFormat,
-	XMLFormat,
 	Base64Format,
 	UriFormat,
 	ShFormat,
@@ -90,6 +108,10 @@ var Formats = []*Format{
 	LuaFormat,
 }
 
+func RegisterFormat(f *Format) {
+	Formats = append(Formats, f)
+}
+
 func (f *Format) MatchesName(name string) bool {
 	if f.FormalName == name {
 		return true
@@ -102,7 +124,10 @@ func (f *Format) MatchesName(name string) bool {
 	return false
 }
 
-func (f *Format) GetConfiguredEncoder() Encoder {
+func (f *Format) GetInDocumentEncoder(indent int) Encoder {
+	if f.InDocumentEncoderFactory != nil {
+		return f.InDocumentEncoderFactory(indent)
+	}
 	return f.EncoderFactory()
 }
 

pkg/yqlib/formatting_expressions_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var formattingExpressionScenarios = []formatScenario{
+var formattingExpressionScenarios = []FormatScenario{
 	{
 		description: "Using expression files and comments",
 		skipDoc:     true,
@@ -43,7 +43,7 @@ var formattingExpressionScenarios = []formatScenario{
 }
 
 func documentExpressionScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 
 	if s.skipDoc {
 		return

pkg/yqlib/goccy_yaml_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var goccyYamlFormatScenarios = []formatScenario{
+var goccyYamlFormatScenarios = []FormatScenario{
 	{
 		description: "basic - 3",
 		skipDoc:     true,
@@ -159,7 +159,7 @@ var goccyYamlFormatScenarios = []formatScenario{
 	// },
 }
 
-func testGoccyYamlScenario(t *testing.T, s formatScenario) {
+func testGoccyYamlScenario(t *testing.T, s FormatScenario) {
 	test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewGoccyYAMLDecoder(), NewYamlEncoder(ConfiguredYamlPreferences)), s.description)
 }
 

pkg/yqlib/json_test.go

@@ -79,7 +79,7 @@ const roundTripMultiLineJson = `{
 }
 `
 
-var jsonScenarios = []formatScenario{
+var jsonScenarios = []FormatScenario{
 	{
 		description:  "array empty",
 		skipDoc:      true,
@@ -307,7 +307,7 @@ var jsonScenarios = []formatScenario{
 	},
 }
 
-func documentRoundtripNdJsonScenario(w *bufio.Writer, s formatScenario, indent int) {
+func documentRoundtripNdJsonScenario(w *bufio.Writer, s FormatScenario, indent int) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -335,7 +335,7 @@ func documentRoundtripNdJsonScenario(w *bufio.Writer, s formatScenario, indent i
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewJSONDecoder(), NewJSONEncoder(prefs))))
 }
 
-func documentDecodeNdJsonScenario(w *bufio.Writer, s formatScenario) {
+func documentDecodeNdJsonScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -385,7 +385,7 @@ func decodeJSON(t *testing.T, jsonString string) *CandidateNode {
 	return context.MatchingNodes.Front().Value.(*CandidateNode)
 }
 
-func testJSONScenario(t *testing.T, s formatScenario) {
+func testJSONScenario(t *testing.T, s FormatScenario) {
 	prefs := ConfiguredJSONPreferences.Copy()
 	prefs.Indent = s.indent
 	prefs.UnwrapScalar = false
@@ -413,7 +413,7 @@ func testJSONScenario(t *testing.T, s formatScenario) {
 	}
 }
 
-func documentJSONDecodeScenario(t *testing.T, w *bufio.Writer, s formatScenario) {
+func documentJSONDecodeScenario(t *testing.T, w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -443,7 +443,7 @@ func documentJSONDecodeScenario(t *testing.T, w *bufio.Writer, s formatScenario)
 }
 
 func documentJSONScenario(t *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 	if s.skipDoc {
 		return
 	}
@@ -464,7 +464,7 @@ func documentJSONScenario(t *testing.T, w *bufio.Writer, i interface{}) {
 	}
 }
 
-func documentJSONEncodeScenario(w *bufio.Writer, s formatScenario) {
+func documentJSONEncodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {

pkg/yqlib/lexer_participle.go

@@ -7,7 +7,7 @@ import (
 	"github.com/alecthomas/participle/v2/lexer"
 )
 
-var participleYqRules = []*participleYqRule{
+var participleYqRules = []*ParticipleYqRule{
 	{"LINE_COMMENT", `line_?comment|lineComment`, opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{LineComment: true}), 0},
 	{"HEAD_COMMENT", `head_?comment|headComment`, opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{HeadComment: true}), 0},
 	{"FOOT_COMMENT", `foot_?comment|footComment`, opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{FootComment: true}), 0},
@@ -57,43 +57,34 @@ var participleYqRules = []*participleYqRule{
 
 	{"ArrayToMap", "array_?to_?map", expressionOpToken(`(.[] | select(. != null) ) as $i ireduce({}; .[$i | key] = $i)`), 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},
+	{"YamlEncodeWithIndent", `to_?yaml\([0-9]+\)`, CreateEncodeYqActionParsingIndent(YamlFormat), 0},
 
-	{"YamlDecode", `from_?yaml|@yamld|from_?json|@jsond`, decodeOp(YamlFormat), 0},
-	{"YamlEncode", `to_?yaml|@yaml`, encodeWithIndent(YamlFormat, 2), 0},
+	{"JSONEncodeWithIndent", `to_?json\([0-9]+\)`, CreateEncodeYqActionParsingIndent(JSONFormat), 0},
 
-	{"JSONEncode", `to_?json`, encodeWithIndent(JSONFormat, 2), 0},
-	{"JSONEncodeNoIndent", `@json`, encodeWithIndent(JSONFormat, 0), 0},
+	{"YamlDecode", `from_?yaml|@yamld|from_?json|@jsond`, CreateDecodeOpYqAction(YamlFormat), 0},
+	{"YamlEncode", `to_?yaml|@yaml`, CreateEncodeOpYqAction(YamlFormat, 2), 0},
 
-	{"PropertiesDecode", `from_?props|@propsd`, decodeOp(PropertiesFormat), 0},
-	{"PropsEncode", `to_?props|@props`, encodeWithIndent(PropertiesFormat, 2), 0},
+	{"JSONEncode", `to_?json`, CreateEncodeOpYqAction(JSONFormat, 2), 0},
+	{"JSONEncodeNoIndent", `@json`, CreateEncodeOpYqAction(JSONFormat, 0), 0},
 
-	{"XmlDecode", `from_?xml|@xmld`, decodeOp(XMLFormat), 0},
-	{"XMLEncode", `to_?xml`, encodeWithIndent(XMLFormat, 2), 0},
-	{"XMLEncodeNoIndent", `@xml`, encodeWithIndent(XMLFormat, 0), 0},
+	{"CSVDecode", `from_?csv|@csvd`, CreateDecodeOpYqAction(CSVFormat), 0},
+	{"CSVEncode", `to_?csv|@csv`, CreateEncodeOpYqAction(CSVFormat, 0), 0},
 
-	{"CSVDecode", `from_?csv|@csvd`, decodeOp(CSVFormat), 0},
-	{"CSVEncode", `to_?csv|@csv`, encodeWithIndent(CSVFormat, 0), 0},
+	{"TSVDecode", `from_?tsv|@tsvd`, CreateDecodeOpYqAction(TSVFormat), 0},
+	{"TSVEncode", `to_?tsv|@tsv`, CreateEncodeOpYqAction(TSVFormat, 0), 0},
 
-	{"TSVDecode", `from_?tsv|@tsvd`, decodeOp(TSVFormat), 0},
-	{"TSVEncode", `to_?tsv|@tsv`, encodeWithIndent(TSVFormat, 0), 0},
+	{"Base64d", `@base64d`, CreateDecodeOpYqAction(Base64Format), 0},
+	{"Base64", `@base64`, CreateEncodeOpYqAction(Base64Format, 0), 0},
 
-	{"Base64d", `@base64d`, decodeOp(Base64Format), 0},
-	{"Base64", `@base64`, encodeWithIndent(Base64Format, 0), 0},
+	{"Urid", `@urid`, CreateDecodeOpYqAction(UriFormat), 0},
+	{"Uri", `@uri`, CreateEncodeOpYqAction(UriFormat, 0), 0},
+	{"SH", `@sh`, CreateEncodeOpYqAction(ShFormat, 0), 0},
 
-	{"Urid", `@urid`, decodeOp(UriFormat), 0},
-	{"Uri", `@uri`, encodeWithIndent(UriFormat, 0), 0},
-	{"SH", `@sh`, encodeWithIndent(ShFormat, 0), 0},
+	{"LoadBase64", `load_?base64`, CreateLoadOpYqAction(NewBase64Decoder()), 0},
 
-	{"LoadXML", `load_?xml|xml_?load`, loadOp(NewXMLDecoder(ConfiguredXMLPreferences)), 0},
+	simpleOp(`load_?str|str_?load`, loadStringOpType),
 
-	{"LoadBase64", `load_?base64`, loadOp(NewBase64Decoder()), 0},
-
-	{"LoadProperties", `load_?props`, loadOp(NewPropertiesDecoder()), 0},
-	simpleOp("load_?str|str_?load", loadStringOpType),
-	{"LoadYaml", `load`, loadOp(NewYamlDecoder(LoadYamlPreferences)), 0},
+	{"LoadYaml", `load`, CreateLoadOpYqAction(NewYamlDecoder(LoadYamlPreferences)), 0},
 
 	{"SplitDocument", `splitDoc|split_?doc`, opToken(splitDocumentOpType), 0},
 
@@ -227,7 +218,7 @@ var participleYqRules = []*participleYqRule{
 
 type yqAction func(lexer.Token) (*token, error)
 
-type participleYqRule struct {
+type ParticipleYqRule struct {
 	Name                string
 	Pattern             string
 	CreateYqToken       yqAction
@@ -238,12 +229,16 @@ type participleLexer struct {
 	lexerDefinition lexer.StringDefinition
 }
 
-func simpleOp(name string, opType *operationType) *participleYqRule {
-	return &participleYqRule{strings.ToUpper(string(name[1])) + name[1:], name, opToken(opType), 0}
+func simpleOp(name string, opType *operationType) *ParticipleYqRule {
+	return &ParticipleYqRule{strings.ToUpper(string(name[1])) + name[1:], name, opToken(opType), 0}
 }
 
-func assignableOp(name string, opType *operationType, assignOpType *operationType) *participleYqRule {
-	return &participleYqRule{strings.ToUpper(string(name[1])) + name[1:], name, opTokenWithPrefs(opType, assignOpType, nil), 0}
+func assignableOp(name string, opType *operationType, assignOpType *operationType) *ParticipleYqRule {
+	return &ParticipleYqRule{strings.ToUpper(string(name[1])) + name[1:], name, opTokenWithPrefs(opType, assignOpType, nil), 0}
+}
+
+func RegisterRules(rules []*ParticipleYqRule) {
+	participleYqRules = append(participleYqRules, rules...)
 }
 
 func newParticipleLexer() expressionTokeniser {
@@ -523,7 +518,7 @@ func parentWithDefaultLevel() yqAction {
 	}
 }
 
-func encodeParseIndent(outputFormat *Format) yqAction {
+func CreateEncodeYqActionParsingIndent(outputFormat *Format) yqAction {
 	return func(rawToken lexer.Token) (*token, error) {
 		value := rawToken.Value
 		var indent, errParsingInt = extractNumberParameter(value)
@@ -537,17 +532,17 @@ func encodeParseIndent(outputFormat *Format) yqAction {
 	}
 }
 
-func encodeWithIndent(outputFormat *Format, indent int) yqAction {
+func CreateEncodeOpYqAction(outputFormat *Format, indent int) yqAction {
 	prefs := encoderPreferences{format: outputFormat, indent: indent}
 	return opTokenWithPrefs(encodeOpType, nil, prefs)
 }
 
-func decodeOp(format *Format) yqAction {
+func CreateDecodeOpYqAction(format *Format) yqAction {
 	prefs := decoderPreferences{format: format}
 	return opTokenWithPrefs(decodeOpType, nil, prefs)
 }
 
-func loadOp(decoder Decoder) yqAction {
+func CreateLoadOpYqAction(decoder Decoder) yqAction {
 	prefs := loadPrefs{decoder}
 	return opTokenWithPrefs(loadOpType, nil, prefs)
 }
@@ -562,13 +557,13 @@ func literalToken(tt tokenType, checkForPost bool) yqAction {
 	}
 }
 
-func (p *participleLexer) getYqDefinition(rawToken lexer.Token) *participleYqRule {
+func (p *participleLexer) getYqDefinition(rawToken lexer.Token) *ParticipleYqRule {
 	for _, yqRule := range participleYqRules {
 		if yqRule.ParticipleTokenType == rawToken.Type {
 			return yqRule
 		}
 	}
-	return &participleYqRule{}
+	return &ParticipleYqRule{}
 }
 
 func (p *participleLexer) Tokenise(expression string) ([]*token, error) {

pkg/yqlib/lib.go

@@ -98,7 +98,7 @@ func parseSnippet(value string) (*CandidateNode, error) {
 	if result.Tag == "!!str" {
 		// use the original string value, as
 		// decoding drops new lines
-		return createScalarNode(value, value), nil
+		return CreateScalarNode(value, value), nil
 	}
 	result.Line = 0
 	result.Column = 0
@@ -114,8 +114,8 @@ func recursiveNodeEqual(lhs *CandidateNode, rhs *CandidateNode) bool {
 		//process custom tags of scalar nodes.
 		//dont worry about matching tags of maps or arrays.
 
-		lhsTag := lhs.guessTagFromCustomType()
-		rhsTag := rhs.guessTagFromCustomType()
+		lhsTag := lhs.GuessTagFromCustomType()
+		rhsTag := rhs.GuessTagFromCustomType()
 
 		if lhsTag != rhsTag {
 			return false
@@ -161,22 +161,6 @@ func parseInt(numberString string) (int, error) {
 	return int(parsed), err
 }
 
-func headAndLineComment(node *CandidateNode) string {
-	return headComment(node) + lineComment(node)
-}
-
-func headComment(node *CandidateNode) string {
-	return strings.Replace(node.HeadComment, "#", "", 1)
-}
-
-func lineComment(node *CandidateNode) string {
-	return strings.Replace(node.LineComment, "#", "", 1)
-}
-
-func footComment(node *CandidateNode) string {
-	return strings.Replace(node.FootComment, "#", "", 1)
-}
-
 // use for debugging only
 func NodesToString(collection *list.List) string {
 	if !log.IsEnabledFor(logging.DEBUG) {

pkg/yqlib/lua_test.go

@@ -10,7 +10,7 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var luaScenarios = []formatScenario{
+var luaScenarios = []FormatScenario{
 	{
 		description: "Basic input example",
 		input: `return {
@@ -250,7 +250,7 @@ numbers:
 	},
 }
 
-func testLuaScenario(t *testing.T, s formatScenario) {
+func testLuaScenario(t *testing.T, s FormatScenario) {
 	switch s.scenarioType {
 	case "", "decode":
 		test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewLuaDecoder(ConfiguredLuaPreferences), NewYamlEncoder(ConfiguredYamlPreferences)), s.description)
@@ -278,7 +278,7 @@ func testLuaScenario(t *testing.T, s formatScenario) {
 }
 
 func documentLuaScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 
 	if s.skipDoc {
 		return
@@ -295,7 +295,7 @@ func documentLuaScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
 	}
 }
 
-func documentLuaDecodeScenario(w *bufio.Writer, s formatScenario) {
+func documentLuaDecodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -317,7 +317,7 @@ func documentLuaDecodeScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewLuaDecoder(ConfiguredLuaPreferences), NewYamlEncoder(ConfiguredYamlPreferences))))
 }
 
-func documentLuaEncodeScenario(w *bufio.Writer, s formatScenario) {
+func documentLuaEncodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -359,7 +359,7 @@ func documentLuaEncodeScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```lua\n%v```\n\n", mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewLuaEncoder(prefs))))
 }
 
-func documentLuaRoundTripScenario(w *bufio.Writer, s formatScenario) {
+func documentLuaRoundTripScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {

pkg/yqlib/operation.go

@@ -26,7 +26,7 @@ var valueToStringFunc = func(p *Operation) string {
 
 func createValueOperation(value interface{}, stringValue string) *Operation {
 	log.Debug("creating value op for string %v", stringValue)
-	var node = createScalarNode(value, stringValue)
+	var node = CreateScalarNode(value, stringValue)
 
 	return &Operation{
 		OperationType: valueOpType,

pkg/yqlib/operator_add.go

@@ -74,11 +74,11 @@ func add(_ *dataTreeNavigator, context Context, lhs *CandidateNode, rhs *Candida
 
 func addScalars(context Context, target *CandidateNode, lhs *CandidateNode, rhs *CandidateNode) error {
 	lhsTag := lhs.Tag
-	rhsTag := rhs.guessTagFromCustomType()
+	rhsTag := rhs.GuessTagFromCustomType()
 	lhsIsCustom := false
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 		lhsIsCustom = true
 	}
 

pkg/yqlib/operator_assign.go

@@ -6,6 +6,10 @@ type assignPreferences struct {
 	ClobberCustomTags   bool
 }
 
+func PerformAssignment(context Context, path []interface{}) {
+
+}
+
 func assignUpdateFunc(prefs assignPreferences) crossFunctionCalculation {
 	return func(d *dataTreeNavigator, context Context, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
 		if !prefs.OnlyWriteNull || lhs.Tag == "!!null" {

pkg/yqlib/operator_compare.go

@@ -69,8 +69,8 @@ func compareDateTime(layout string, prefs compareTypePref, lhs *CandidateNode, r
 }
 
 func compareScalars(context Context, prefs compareTypePref, lhs *CandidateNode, rhs *CandidateNode) (bool, error) {
-	lhsTag := lhs.guessTagFromCustomType()
-	rhsTag := rhs.guessTagFromCustomType()
+	lhsTag := lhs.GuessTagFromCustomType()
+	rhsTag := rhs.GuessTagFromCustomType()
 
 	isDateTime := lhs.Tag == "!!timestamp"
 	// if the lhs is a string, it might be a timestamp in a custom format.

pkg/yqlib/operator_datetime.go

@@ -141,7 +141,7 @@ func fromUnixOp(_ *dataTreeNavigator, context Context, _ *ExpressionNode) (Conte
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 
-		actualTag := candidate.guessTagFromCustomType()
+		actualTag := candidate.GuessTagFromCustomType()
 
 		if actualTag != "!!int" && actualTag != "!!float" {
 			return Context{}, fmt.Errorf("from_unix only works on numbers, found %v instead", candidate.Tag)

pkg/yqlib/operator_divide.go

@@ -32,11 +32,11 @@ func divide(_ *dataTreeNavigator, _ Context, lhs *CandidateNode, rhs *CandidateN
 
 func divideScalars(target *CandidateNode, lhs *CandidateNode, rhs *CandidateNode) error {
 	lhsTag := lhs.Tag
-	rhsTag := rhs.guessTagFromCustomType()
+	rhsTag := rhs.GuessTagFromCustomType()
 	lhsIsCustom := false
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 		lhsIsCustom = true
 	}
 

pkg/yqlib/operator_encoder_decoder.go

@@ -9,33 +9,11 @@ import (
 	"strings"
 )
 
-func configureEncoder(format *Format, indent int) Encoder {
-
-	switch format {
-	case JSONFormat:
-		prefs := ConfiguredJSONPreferences.Copy()
-		prefs.Indent = indent
-		prefs.ColorsEnabled = false
-		prefs.UnwrapScalar = false
-		return NewJSONEncoder(prefs)
-	case YamlFormat:
-		var prefs = ConfiguredYamlPreferences.Copy()
-		prefs.Indent = indent
-		prefs.ColorsEnabled = false
-		return NewYamlEncoder(prefs)
-	case XMLFormat:
-		var xmlPrefs = ConfiguredXMLPreferences.Copy()
-		xmlPrefs.Indent = indent
-		return NewXMLEncoder(xmlPrefs)
-	}
-	return format.EncoderFactory()
-}
-
 func encodeToString(candidate *CandidateNode, prefs encoderPreferences) (string, error) {
 	var output bytes.Buffer
 	log.Debug("printing with indent: %v", prefs.indent)
 
-	encoder := configureEncoder(prefs.format, prefs.indent)
+	encoder := prefs.format.GetInDocumentEncoder(prefs.indent)
 	if encoder == nil {
 		return "", errors.New("no support for output format")
 	}

pkg/yqlib/operator_entries.go

@@ -64,7 +64,7 @@ func toEntriesOperator(_ *dataTreeNavigator, context Context, _ *ExpressionNode)
 func parseEntry(candidateNode *CandidateNode, position int) (*CandidateNode, *CandidateNode, error) {
 	prefs := traversePreferences{DontAutoCreate: true}
 
-	keyResults, err := traverseMap(Context{}, candidateNode, createStringScalarNode("key"), prefs, false)
+	keyResults, err := traverseMap(Context{}, candidateNode, CreateStringScalarNode("key"), prefs, false)
 
 	if err != nil {
 		return nil, nil, err
@@ -72,7 +72,7 @@ func parseEntry(candidateNode *CandidateNode, position int) (*CandidateNode, *Ca
 		return nil, nil, fmt.Errorf("expected to find one 'key' entry but found %v in position %v", keyResults.Len(), position)
 	}
 
-	valueResults, err := traverseMap(Context{}, candidateNode, createStringScalarNode("value"), prefs, false)
+	valueResults, err := traverseMap(Context{}, candidateNode, CreateStringScalarNode("value"), prefs, false)
 
 	if err != nil {
 		return nil, nil, err

pkg/yqlib/operator_modulo.go

@@ -33,11 +33,11 @@ func modulo(_ *dataTreeNavigator, _ Context, lhs *CandidateNode, rhs *CandidateN
 
 func moduloScalars(target *CandidateNode, lhs *CandidateNode, rhs *CandidateNode) error {
 	lhsTag := lhs.Tag
-	rhsTag := rhs.guessTagFromCustomType()
+	rhsTag := rhs.GuessTagFromCustomType()
 	lhsIsCustom := false
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 		lhsIsCustom = true
 	}
 

pkg/yqlib/operator_multiply.go

@@ -79,11 +79,11 @@ func multiply(preferences multiplyPreferences) func(d *dataTreeNavigator, contex
 
 func multiplyScalars(lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
 	lhsTag := lhs.Tag
-	rhsTag := rhs.guessTagFromCustomType()
+	rhsTag := rhs.GuessTagFromCustomType()
 	lhsIsCustom := false
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 		lhsIsCustom = true
 	}
 

pkg/yqlib/operator_sort.go

@@ -92,12 +92,12 @@ func (a sortableNodeArray) compare(lhs *CandidateNode, rhs *CandidateNode, dateT
 
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 	}
 
 	if !strings.HasPrefix(rhsTag, "!!") {
 		// custom tag - we have to have a guess
-		rhsTag = rhs.guessTagFromCustomType()
+		rhsTag = rhs.GuessTagFromCustomType()
 	}
 
 	isDateTime := lhsTag == "!!timestamp" && rhsTag == "!!timestamp"

pkg/yqlib/operator_strings.go

@@ -98,7 +98,7 @@ func interpolate(d *dataTreeNavigator, context Context, str string) (string, err
 func stringInterpolationOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
 	if !StringInterpolationEnabled {
 		return context.SingleChildContext(
-			createScalarNode(expressionNode.Operation.StringValue, expressionNode.Operation.StringValue),
+			CreateScalarNode(expressionNode.Operation.StringValue, expressionNode.Operation.StringValue),
 		), nil
 	}
 	if context.MatchingNodes.Len() == 0 {
@@ -106,7 +106,7 @@ func stringInterpolationOperator(d *dataTreeNavigator, context Context, expressi
 		if err != nil {
 			return Context{}, err
 		}
-		node := createScalarNode(value, value)
+		node := CreateScalarNode(value, value)
 		return context.SingleChildContext(node), nil
 	}
 
@@ -118,7 +118,7 @@ func stringInterpolationOperator(d *dataTreeNavigator, context Context, expressi
 		if err != nil {
 			return Context{}, err
 		}
-		node := createScalarNode(value, value)
+		node := CreateScalarNode(value, value)
 		results.PushBack(node)
 	}
 
@@ -130,7 +130,7 @@ func trimSpaceOperator(_ *dataTreeNavigator, context Context, _ *ExpressionNode)
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
 
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot trim %v, can only operate on strings. ", node.Tag)
 		}
 
@@ -175,7 +175,7 @@ func changeCaseOperator(_ *dataTreeNavigator, context Context, expressionNode *E
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
 
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot change case with %v, can only operate on strings. ", node.Tag)
 		}
 
@@ -246,7 +246,7 @@ func substituteStringOperator(d *dataTreeNavigator, context Context, expressionN
 
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot substitute with %v, can only substitute strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
 		}
 
@@ -261,29 +261,29 @@ func substituteStringOperator(d *dataTreeNavigator, context Context, expressionN
 func addMatch(original []*CandidateNode, match string, offset int, name string) []*CandidateNode {
 
 	newContent := append(original,
-		createScalarNode("string", "string"))
+		CreateScalarNode("string", "string"))
 
 	if offset < 0 {
 		// offset of -1 means there was no match, force a null value like jq
 		newContent = append(newContent,
-			createScalarNode(nil, "null"),
+			CreateScalarNode(nil, "null"),
 		)
 	} else {
 		newContent = append(newContent,
-			createScalarNode(match, match),
+			CreateScalarNode(match, match),
 		)
 	}
 
 	newContent = append(newContent,
-		createScalarNode("offset", "offset"),
-		createScalarNode(offset, fmt.Sprintf("%v", offset)),
-		createScalarNode("length", "length"),
-		createScalarNode(len(match), fmt.Sprintf("%v", len(match))))
+		CreateScalarNode("offset", "offset"),
+		CreateScalarNode(offset, fmt.Sprintf("%v", offset)),
+		CreateScalarNode("length", "length"),
+		CreateScalarNode(len(match), fmt.Sprintf("%v", len(match))))
 
 	if name != "" {
 		newContent = append(newContent,
-			createScalarNode("name", "name"),
-			createScalarNode(name, name),
+			CreateScalarNode("name", "name"),
+			CreateScalarNode(name, name),
 		)
 	}
 	return newContent
@@ -330,7 +330,7 @@ func match(matchPrefs matchPreferences, regEx *regexp.Regexp, candidate *Candida
 
 		node := candidate.CreateReplacement(MappingNode, "!!map", "")
 		node.AddChildren(addMatch(node.Content, match, allIndices[i][0], ""))
-		node.AddKeyValueChild(createScalarNode("captures", "captures"), capturesListNode)
+		node.AddKeyValueChild(CreateScalarNode("captures", "captures"), capturesListNode)
 		results.PushBack(node)
 
 	}
@@ -353,15 +353,15 @@ func capture(matchPrefs matchPreferences, regEx *regexp.Regexp, candidate *Candi
 		_, submatches := matches[0], matches[1:]
 		for j, submatch := range submatches {
 
-			keyNode := createScalarNode(subNames[j+1], subNames[j+1])
+			keyNode := CreateScalarNode(subNames[j+1], subNames[j+1])
 			var valueNode *CandidateNode
 
 			offset := allIndices[i][2+j*2]
 			// offset of -1 means there was no match, force a null value like jq
 			if offset < 0 {
-				valueNode = createScalarNode(nil, "null")
+				valueNode = CreateScalarNode(nil, "null")
 			} else {
-				valueNode = createScalarNode(submatch, submatch)
+				valueNode = CreateScalarNode(submatch, submatch)
 			}
 			capturesNode.AddKeyValueChild(keyNode, valueNode)
 		}
@@ -425,7 +425,7 @@ func matchOperator(d *dataTreeNavigator, context Context, expressionNode *Expres
 
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot match with %v, can only match strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
 		}
 
@@ -445,7 +445,7 @@ func captureOperator(d *dataTreeNavigator, context Context, expressionNode *Expr
 
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot match with %v, can only match strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
 		}
 		capture(matchPrefs, regEx, node, node.Value, results)
@@ -465,7 +465,7 @@ func testOperator(d *dataTreeNavigator, context Context, expressionNode *Express
 
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		node := el.Value.(*CandidateNode)
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot match with %v, can only match strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
 		}
 		matches := regEx.FindStringSubmatch(node.Value)
@@ -535,7 +535,7 @@ func splitStringOperator(d *dataTreeNavigator, context Context, expressionNode *
 			continue
 		}
 
-		if node.guessTagFromCustomType() != "!!str" {
+		if node.GuessTagFromCustomType() != "!!str" {
 			return Context{}, fmt.Errorf("cannot split %v, can only split strings", node.Tag)
 		}
 		kind, tag, content := split(node.Value, splitStr)

pkg/yqlib/operator_subtract.go

@@ -77,13 +77,13 @@ func subtractScalars(context Context, target *CandidateNode, lhs *CandidateNode,
 	lhsIsCustom := false
 	if !strings.HasPrefix(lhsTag, "!!") {
 		// custom tag - we have to have a guess
-		lhsTag = lhs.guessTagFromCustomType()
+		lhsTag = lhs.GuessTagFromCustomType()
 		lhsIsCustom = true
 	}
 
 	if !strings.HasPrefix(rhsTag, "!!") {
 		// custom tag - we have to have a guess
-		rhsTag = rhs.guessTagFromCustomType()
+		rhsTag = rhs.GuessTagFromCustomType()
 	}
 
 	isDateTime := lhsTag == "!!timestamp"

pkg/yqlib/operator_traverse_path.go

@@ -54,7 +54,7 @@ func traverse(context Context, matchingNode *CandidateNode, operation *Operation
 	switch matchingNode.Kind {
 	case MappingNode:
 		log.Debug("its a map with %v entries", len(matchingNode.Content)/2)
-		return traverseMap(context, matchingNode, createStringScalarNode(operation.StringValue), operation.Preferences.(traversePreferences), false)
+		return traverseMap(context, matchingNode, CreateStringScalarNode(operation.StringValue), operation.Preferences.(traversePreferences), false)
 
 	case SequenceNode:
 		log.Debug("its a sequence of %v things!", len(matchingNode.Content))
@@ -149,7 +149,7 @@ func traverseArrayIndices(context Context, matchingNode *CandidateNode, indicesT
 
 func traverseMapWithIndices(context Context, candidate *CandidateNode, indices []*CandidateNode, prefs traversePreferences) (*list.List, error) {
 	if len(indices) == 0 {
-		return traverseMap(context, candidate, createStringScalarNode(""), prefs, true)
+		return traverseMap(context, candidate, CreateStringScalarNode(""), prefs, true)
 	}
 
 	var matchingNodeMap = list.New()
@@ -196,7 +196,7 @@ func traverseArrayWithIndices(node *CandidateNode, indices []*CandidateNode, pre
 				node.Style = 0
 			}
 
-			valueNode := createScalarNode(nil, "null")
+			valueNode := CreateScalarNode(nil, "null")
 			node.AddChild(valueNode)
 			contentLength = len(node.Content)
 		}

pkg/yqlib/printer_writer.go

@@ -34,14 +34,7 @@ type multiPrintWriter struct {
 }
 
 func NewMultiPrinterWriter(expression *ExpressionNode, format *Format) PrinterWriter {
-	extension := "yml"
-
-	switch format {
-	case JSONFormat:
-		extension = "json"
-	case PropertiesFormat:
-		extension = "properties"
-	}
+	extension := format.DefaultExtension
 
 	return &multiPrintWriter{
 		nameExpression: expression,

pkg/yqlib/properties.go

@@ -1,25 +0,0 @@
-package yqlib
-
-type PropertiesPreferences struct {
-	UnwrapScalar      bool
-	KeyValueSeparator string
-	UseArrayBrackets  bool
-}
-
-func NewDefaultPropertiesPreferences() PropertiesPreferences {
-	return PropertiesPreferences{
-		UnwrapScalar:      true,
-		KeyValueSeparator: " = ",
-		UseArrayBrackets:  false,
-	}
-}
-
-func (p *PropertiesPreferences) Copy() PropertiesPreferences {
-	return PropertiesPreferences{
-		UnwrapScalar:      p.UnwrapScalar,
-		KeyValueSeparator: p.KeyValueSeparator,
-		UseArrayBrackets:  p.UseArrayBrackets,
-	}
-}
-
-var ConfiguredPropertiesPreferences = NewDefaultPropertiesPreferences()

pkg/yqlib/properties_test.go

@@ -155,7 +155,7 @@ emptyArray =
 emptyMap = 
 `
 
-var propertyScenarios = []formatScenario{
+var propertyScenarios = []FormatScenario{
 	{
 		description:    "Encode properties",
 		subdescription: "Note that empty arrays and maps are not encoded by default.",
@@ -295,7 +295,7 @@ var propertyScenarios = []formatScenario{
 	},
 }
 
-func documentUnwrappedEncodePropertyScenario(w *bufio.Writer, s formatScenario) {
+func documentUnwrappedEncodePropertyScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -331,7 +331,7 @@ func documentUnwrappedEncodePropertyScenario(w *bufio.Writer, s formatScenario)
 	writeOrPanic(w, fmt.Sprintf("```properties\n%v```\n\n", mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewPropertiesEncoder(prefs))))
 }
 
-func documentWrappedEncodePropertyScenario(w *bufio.Writer, s formatScenario) {
+func documentWrappedEncodePropertyScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -357,7 +357,7 @@ func documentWrappedEncodePropertyScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```properties\n%v```\n\n", mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewPropertiesEncoder(prefs))))
 }
 
-func documentDecodePropertyScenario(w *bufio.Writer, s formatScenario) {
+func documentDecodePropertyScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -382,7 +382,7 @@ func documentDecodePropertyScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewPropertiesDecoder(), NewYamlEncoder(ConfiguredYamlPreferences))))
 }
 
-func documentRoundTripPropertyScenario(w *bufio.Writer, s formatScenario) {
+func documentRoundTripPropertyScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -408,7 +408,7 @@ func documentRoundTripPropertyScenario(w *bufio.Writer, s formatScenario) {
 }
 
 func documentPropertyScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 	if s.skipDoc {
 		return
 	}

pkg/yqlib/shellvariables_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var shellVariablesScenarios = []formatScenario{
+var shellVariablesScenarios = []FormatScenario{
 	{
 		description:    "Encode shell variables",
 		subdescription: "Note that comments are dropped and values will be enclosed in single quotes as needed.",
@@ -69,7 +69,7 @@ func TestShellVariableScenarios(t *testing.T) {
 }
 
 func documentShellVariableScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 	if s.skipDoc {
 		return
 	}

pkg/yqlib/stream_evaluator.go

@@ -31,7 +31,7 @@ func (s *streamEvaluator) EvaluateNew(expression string, printer Printer) error
 	if err != nil {
 		return err
 	}
-	candidateNode := createScalarNode(nil, "")
+	candidateNode := CreateScalarNode(nil, "")
 	inputList := list.New()
 	inputList.PushBack(candidateNode)
 

pkg/yqlib/toml_test.go

@@ -79,7 +79,7 @@ var expectedSampleWithHeader = `servers:
     ip: 10.0.0.1
 `
 
-var tomlScenarios = []formatScenario{
+var tomlScenarios = []FormatScenario{
 	{
 		skipDoc:      true,
 		description:  "blank",
@@ -240,7 +240,7 @@ var tomlScenarios = []formatScenario{
 	},
 }
 
-func testTomlScenario(t *testing.T, s formatScenario) {
+func testTomlScenario(t *testing.T, s FormatScenario) {
 	switch s.scenarioType {
 	case "", "decode":
 		test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewTomlDecoder(), NewYamlEncoder(ConfiguredYamlPreferences)), s.description)
@@ -256,7 +256,7 @@ func testTomlScenario(t *testing.T, s formatScenario) {
 	}
 }
 
-func documentTomlDecodeScenario(w *bufio.Writer, s formatScenario) {
+func documentTomlDecodeScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -278,7 +278,7 @@ func documentTomlDecodeScenario(w *bufio.Writer, s formatScenario) {
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", mustProcessFormatScenario(s, NewTomlDecoder(), NewYamlEncoder(ConfiguredYamlPreferences))))
 }
 
-func documentTomlRoundtripScenario(w *bufio.Writer, s formatScenario) {
+func documentTomlRoundtripScenario(w *bufio.Writer, s FormatScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
@@ -301,7 +301,7 @@ func documentTomlRoundtripScenario(w *bufio.Writer, s formatScenario) {
 }
 
 func documentTomlScenario(_ *testing.T, w *bufio.Writer, i interface{}) {
-	s := i.(formatScenario)
+	s := i.(FormatScenario)
 
 	if s.skipDoc {
 		return

pkg/yqlib/utils.go

@@ -26,7 +26,7 @@ func readStream(filename string) (io.Reader, error) {
 
 }
 
-func writeString(writer io.Writer, txt string) error {
+func WriteString(writer io.Writer, txt string) error {
 	_, errorWriting := writer.Write([]byte(txt))
 	return errorWriting
 }

pkg/yqlib/yaml_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var yamlFormatScenarios = []formatScenario{
+var yamlFormatScenarios = []FormatScenario{
 	{
 		description: "scalar with doc separator",
 		skipDoc:     true,
@@ -111,7 +111,7 @@ var yamlParseScenarios = []expressionScenario{
 	},
 }
 
-func testYamlScenario(t *testing.T, s formatScenario) {
+func testYamlScenario(t *testing.T, s FormatScenario) {
 	test.AssertResultWithContext(t, s.expected, mustProcessFormatScenario(s, NewYamlDecoder(ConfiguredYamlPreferences), NewYamlEncoder(ConfiguredYamlPreferences)), s.description)
 }
 

release_notes.txt

@@ -1,5 +1,5 @@
 4.43.1: (not released yet)
-  - Added tostring #72
+  - Added to_string #72
   - Added string interpolation #1149
   - Can specify parent(n) levels #1970
   - Fixed CSV line break issue #1974
@@ -151,7 +151,7 @@
   - XML Decoder: Fixed issue where content surrounding tags are lost #1447
   - XML Decoder: Fixed xml decode bug when there is content after a comment
   - Fixed loading yaml with header issue #1445
-  - guessTagFromCustomType warning log is now a debug.
+  - GuessTagFromCustomType warning log is now a debug.
   - Special thanks to @Kopfbremse for reporting XML issues!
 
 4.30.4:

yq.go

@@ -4,9 +4,14 @@ import (
 	"os"
 
 	command "github.com/mikefarah/yq/v4/cmd"
+	"github.com/mikefarah/yq/v4/pkg/properties"
+	"github.com/mikefarah/yq/v4/pkg/xml"
 )
 
 func main() {
+	properties.RegisterPropertiesFormat()
+	xml.RegisterXmlFormat()
+
 	cmd := command.New()
 
 	args := os.Args[1:]