incrementing version

Dockerfile

@@ -22,4 +22,4 @@ LABEL version=${VERSION}
 
 WORKDIR /workdir
 
-ENTRYPOINT [/usr/bin/yq]
+ENTRYPOINT ["/usr/bin/yq"]

cmd/constant.go

@@ -2,10 +2,10 @@ package cmd
 
 var unwrapScalar = true
 
-// var writeInplace = false
+var writeInplace = false
 var outputToJSON = false
 
-// var exitStatus = false
+var exitStatus = false
 var forceColor = false
 var forceNoColor = false
 var colorsEnabled = false
@@ -15,4 +15,4 @@ var nullInput = false
 var verbose = false
 var version = false
 
-// var log = logging.MustGetLogger("yq")
+var completedSuccessfully = false

cmd/evaluate_all_command.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"errors"
+	"fmt"
 	"os"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
@@ -23,6 +25,7 @@ yq es -n '{"a": "b"}'
 	return cmdEvalAll
 }
 func evaluateAll(cmd *cobra.Command, args []string) error {
+	cmd.SilenceUsage = true
 	// 0 args, read std in
 	// 1 arg, null input, process expression
 	// 1 arg, read file in sequence
@@ -39,26 +42,50 @@ func evaluateAll(cmd *cobra.Command, args []string) error {
 	if forceColor || (!forceNoColor && (fileInfo.Mode()&os.ModeCharDevice) != 0) {
 		colorsEnabled = true
 	}
+
+	if writeInplace && len(args) < 2 {
+		return fmt.Errorf("Write inplace flag only applicable when giving an expression and at least one file")
+	}
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[1])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() { writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully) }()
+	}
+
 	printer := yqlib.NewPrinter(out, outputToJSON, unwrapScalar, colorsEnabled, indent, !noDocSeparators)
 
+	allAtOnceEvaluator := yqlib.NewAllAtOnceEvaluator()
 	switch len(args) {
 	case 0:
 		if pipingStdIn {
-			err = yqlib.EvaluateAllFileStreams("", []string{"-"}, printer)
+			err = allAtOnceEvaluator.EvaluateFiles("", []string{"-"}, printer)
 		} else {
 			cmd.Println(cmd.UsageString())
 			return nil
 		}
 	case 1:
 		if nullInput {
-			err = yqlib.EvaluateAllFileStreams(args[0], []string{}, printer)
+			err = yqlib.NewStreamEvaluator().EvaluateNew(args[0], printer)
 		} else {
-			err = yqlib.EvaluateAllFileStreams("", []string{args[0]}, printer)
+			err = allAtOnceEvaluator.EvaluateFiles("", []string{args[0]}, printer)
 		}
 	default:
-		err = yqlib.EvaluateAllFileStreams(args[0], args[1:], printer)
+		err = allAtOnceEvaluator.EvaluateFiles(args[0], args[1:], printer)
+	}
+
+	completedSuccessfully = err == nil
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
 	}
 
-	cmd.SilenceUsage = true
 	return err
 }

cmd/evalute_sequence_command.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"errors"
+	"fmt"
 	"os"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
@@ -23,6 +25,7 @@ yq es -n '{"a": "b"}'
 	return cmdEvalSequence
 }
 func evaluateSequence(cmd *cobra.Command, args []string) error {
+	cmd.SilenceUsage = true
 	// 0 args, read std in
 	// 1 arg, null input, process expression
 	// 1 arg, read file in sequence
@@ -39,26 +42,50 @@ func evaluateSequence(cmd *cobra.Command, args []string) error {
 	if forceColor || (!forceNoColor && (fileInfo.Mode()&os.ModeCharDevice) != 0) {
 		colorsEnabled = true
 	}
+
+	if writeInplace && len(args) < 2 {
+		return fmt.Errorf("Write inplace flag only applicable when giving an expression and at least one file")
+	}
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[1])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() { writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully) }()
+	}
+
 	printer := yqlib.NewPrinter(out, outputToJSON, unwrapScalar, colorsEnabled, indent, !noDocSeparators)
 
+	streamEvaluator := yqlib.NewStreamEvaluator()
+
 	switch len(args) {
 	case 0:
 		if pipingStdIn {
-			err = yqlib.EvaluateFileStreamsSequence("", []string{"-"}, printer)
+			err = streamEvaluator.EvaluateFiles("", []string{"-"}, printer)
 		} else {
 			cmd.Println(cmd.UsageString())
 			return nil
 		}
 	case 1:
 		if nullInput {
-			err = yqlib.EvaluateAllFileStreams(args[0], []string{}, printer)
+			err = streamEvaluator.EvaluateNew(args[0], printer)
 		} else {
-			err = yqlib.EvaluateFileStreamsSequence("", []string{args[0]}, printer)
+			err = streamEvaluator.EvaluateFiles("", []string{args[0]}, printer)
 		}
 	default:
-		err = yqlib.EvaluateFileStreamsSequence(args[0], args[1:], printer)
+		err = streamEvaluator.EvaluateFiles(args[0], args[1:], printer)
+	}
+	completedSuccessfully = err == nil
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
 	}
 
-	cmd.SilenceUsage = true
 	return err
 }

cmd/root.go

@@ -46,6 +46,8 @@ func New() *cobra.Command {
 
 	rootCmd.PersistentFlags().IntVarP(&indent, "indent", "I", 2, "sets indent level for output")
 	rootCmd.Flags().BoolVarP(&version, "version", "V", false, "Print version information and quit")
+	rootCmd.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace of first yaml file given.")
+	rootCmd.PersistentFlags().BoolVarP(&exitStatus, "exit-status", "e", false, "set exit status if there are no matches or null or false is returned")
 
 	rootCmd.PersistentFlags().BoolVarP(&forceColor, "colors", "C", false, "force print with colors")
 	rootCmd.PersistentFlags().BoolVarP(&forceNoColor, "no-colors", "M", false, "force print with no colors")

cmd/version.go

@@ -11,7 +11,7 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "4.0.0-alpha1"
+	Version = "4.0.0-beta1"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
 	// then it means that it is a final release. Otherwise, this is a pre-release

cmd/write.go

@@ -1,61 +0,0 @@
-package cmd
-
-// import (
-// 	"github.com/spf13/cobra"
-// )
-
-// func createWriteCmd() *cobra.Command {
-// 	var cmdWrite = &cobra.Command{
-// 		Use:     "write [yaml_file] [path_expression] [value]",
-// 		Aliases: []string{"w"},
-// 		Short:   "yq w [--inplace/-i] [--script/-s script_file] [--doc/-d index] sample.yaml 'b.e(name==fr*).value' newValue",
-// 		Example: `
-// yq write things.yaml 'a.b.c' true
-// yq write things.yaml 'a.*.c' true
-// yq write things.yaml 'a.**' true
-// yq write things.yaml 'a.(child.subchild==co*).c' true
-// yq write things.yaml 'a.b.c' --tag '!!str' true # force 'true' to be interpreted as a string instead of bool
-// yq write things.yaml 'a.b.c' --tag '!!float' 3
-// yq write --inplace -- things.yaml 'a.b.c' '--cat' # need to use '--' to stop processing arguments as flags
-// yq w -i things.yaml 'a.b.c' cat
-// yq w -i -s update_script.yaml things.yaml
-// yq w things.yaml 'a.b.d[+]' foo # appends a new node to the 'd' array
-// yq w --doc 2 things.yaml 'a.b.d[+]' foo # updates the 3rd document of the yaml file
-//       `,
-// 		Long: `Updates the yaml file w.r.t the given path and value.
-// Outputs to STDOUT unless the inplace flag is used, in which case the file is updated instead.
-
-// Append value to array adds the value to the end of array.
-
-// Update Scripts:
-// Note that you can give an update script to perform more sophisticated update. Update script
-// format is list of update commands (update or delete) like so:
-// ---
-// - command: update
-//   path: b.c
-//   value:
-//     #great
-//     things: frog # wow!
-// - command: delete
-//   path: b.d
-// `,
-// 		RunE: writeProperty,
-// 	}
-// 	cmdWrite.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
-// 	cmdWrite.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for updating yaml")
-// 	cmdWrite.PersistentFlags().StringVarP(&sourceYamlFile, "from", "f", "", "yaml file for updating yaml (as-is)")
-// 	cmdWrite.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
-// 	cmdWrite.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
-// 	cmdWrite.PersistentFlags().StringVarP(&customStyle, "style", "", "", "formatting style of the value: single, double, folded, flow, literal, tagged")
-// 	cmdWrite.PersistentFlags().StringVarP(&anchorName, "anchorName", "", "", "anchor name")
-// 	cmdWrite.PersistentFlags().BoolVarP(&makeAlias, "makeAlias", "", false, "create an alias using the value as the anchor name")
-// 	return cmdWrite
-// }
-
-// func writeProperty(cmd *cobra.Command, args []string) error {
-// 	var updateCommands, updateCommandsError = readUpdateCommands(args, 3, "Must provide <filename> <path_to_update> <value>", true)
-// 	if updateCommandsError != nil {
-// 		return updateCommandsError
-// 	}
-// 	return updateDoc(args[0], updateCommands, cmd.OutOrStdout())
-// }

cmd/write_test.go

@@ -1,610 +0,0 @@
-package cmd
-
-// import (
-// 	"fmt"
-// 	"runtime"
-// 	"strings"
-// 	"testing"
-
-// 	"github.com/mikefarah/yq/v3/test"
-// )
-
-// func TestWriteCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 7
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteKeepCommentsCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3 # comment
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 7 # comment
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteWithTaggedStyleCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --tag=!!str --style=tagged", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: !!str cat
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteWithDoubleQuotedStyleCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=double", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: "cat"
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteUpdateStyleOnlyCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-//   d: things
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* --style=single", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 'dog'
-//   d: 'things'
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteUpdateTagOnlyCmd(t *testing.T) {
-// 	content := `b:
-//   c: true
-//   d: false
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* --tag=!!str", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: "true"
-//   d: "false"
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteWithSingleQuotedStyleCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=single", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 'cat'
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteWithLiteralStyleCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=literal", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: |-
-//     cat
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteWithFoldedStyleCmd(t *testing.T) {
-// 	content := `b:
-//   c: dog
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=folded", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: >-
-//     cat
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteEmptyMultiDocCmd(t *testing.T) {
-// 	content := `# this is empty
-// ---
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `c: 7
-
-// # this is empty
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteSurroundingEmptyMultiDocCmd(t *testing.T) {
-// 	content := `---
-// # empty
-// ---
-// cat: frog
-// ---
-
-// # empty
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d1 c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `
-
-// # empty
-// ---
-// cat: frog
-// c: 7
-// ---
-
-// # empty
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteFromFileCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	source := `kittens: are cute # sure are!`
-// 	fromFilename := test.WriteTempYamlFile(source)
-// 	defer test.RemoveTempYamlFile(fromFilename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c -f %s", filename, fromFilename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c:
-//     kittens: are cute # sure are!
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteEmptyCmd(t *testing.T) {
-// 	content := ``
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 7
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteAutoCreateCmd(t *testing.T) {
-// 	content := `applications:
-//   - name: app
-//     env:`
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s applications[0].env.hello world", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `applications:
-//   - name: app
-//     env:
-//       hello: world
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmdScript(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	updateScript := `- command: update
-//   path: b.c
-//   value: 7`
-// 	scriptFilename := test.WriteTempYamlFile(updateScript)
-// 	defer test.RemoveTempYamlFile(scriptFilename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write --script %s %s", scriptFilename, filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 7
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmdEmptyScript(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	updateScript := ``
-// 	scriptFilename := test.WriteTempYamlFile(updateScript)
-// 	defer test.RemoveTempYamlFile(scriptFilename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write --script %s %s", scriptFilename, filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 3
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteMultiCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// ---
-// apples: great
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d 1 apples ok", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 3
-// ---
-// apples: ok
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-// func TestWriteInvalidDocumentIndexCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -df apples ok", filename))
-// 	if result.Error == nil {
-// 		t.Error("Expected command to fail due to invalid path")
-// 	}
-// 	expectedOutput := `Document index f is not a integer or *: strconv.ParseInt: parsing "f": invalid syntax`
-// 	test.AssertResult(t, expectedOutput, result.Error.Error())
-// }
-
-// func TestWriteBadDocumentIndexCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d 1 apples ok", filename))
-// 	if result.Error == nil {
-// 		t.Error("Expected command to fail due to invalid path")
-// 	}
-// 	expectedOutput := `asked to process document index 1 but there are only 1 document(s)`
-// 	test.AssertResult(t, expectedOutput, result.Error.Error())
-// }
-// func TestWriteMultiAllCmd(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// ---
-// apples: great
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d * apples ok", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: 3
-// apples: ok
-// ---
-// apples: ok`
-// 	test.AssertResult(t, expectedOutput, strings.Trim(result.Output, "\n "))
-// }
-
-// func TestWriteCmd_EmptyArray(t *testing.T) {
-// 	content := `b: 3`
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s a []", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b: 3
-// a: []
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_Error(t *testing.T) {
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, "write")
-// 	if result.Error == nil {
-// 		t.Error("Expected command to fail due to missing arg")
-// 	}
-// 	expectedOutput := `Must provide <filename> <path_to_update> <value>`
-// 	test.AssertResult(t, expectedOutput, result.Error.Error())
-// }
-
-// func TestWriteCmd_ErrorUnreadableFile(t *testing.T) {
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, "write fake-unknown a.b 3")
-// 	if result.Error == nil {
-// 		t.Error("Expected command to fail due to unknown file")
-// 	}
-// 	var expectedOutput string
-// 	if runtime.GOOS == "windows" {
-// 		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
-// 	} else {
-// 		expectedOutput = `open fake-unknown: no such file or directory`
-// 	}
-// 	test.AssertResult(t, expectedOutput, result.Error.Error())
-// }
-
-// func TestWriteCmd_Inplace(t *testing.T) {
-// 	content := `b:
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write -i %s b.c 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	gotOutput := test.ReadTempYamlFile(filename)
-// 	expectedOutput := `b:
-//   c: 7`
-// 	test.AssertResult(t, expectedOutput, strings.Trim(gotOutput, "\n "))
-// }
-
-// func TestWriteCmd_InplaceError(t *testing.T) {
-// 	content := `b: cat
-//   c: 3
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write -i %s b.c 7", filename))
-// 	if result.Error == nil {
-// 		t.Error("Expected Error to occur!")
-// 	}
-// 	gotOutput := test.ReadTempYamlFile(filename)
-// 	test.AssertResult(t, content, gotOutput)
-// }
-
-// func TestWriteCmd_Append(t *testing.T) {
-// 	content := `b:
-//   - foo
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   - foo
-//   - 7
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_AppendInline(t *testing.T) {
-// 	content := `b: [foo]`
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b: [foo, 7]
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_AppendInlinePretty(t *testing.T) {
-// 	content := `b: [foo]`
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s -P b[+] 7", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   - foo
-//   - 7
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_AppendEmptyArray(t *testing.T) {
-// 	content := `a: 2
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] v", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `a: 2
-// b:
-//   - v
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_SplatArray(t *testing.T) {
-// 	content := `b:
-// - c: thing
-// - c: another thing
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[*].c new", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   - c: new
-//   - c: new
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_SplatMap(t *testing.T) {
-// 	content := `b:
-//   c: thing
-//   d: another thing
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* new", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: new
-//   d: new
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }
-
-// func TestWriteCmd_SplatMapEmpty(t *testing.T) {
-// 	content := `b:
-//   c: thing
-//   d: another thing
-// `
-// 	filename := test.WriteTempYamlFile(content)
-// 	defer test.RemoveTempYamlFile(filename)
-
-// 	cmd := getRootCommand()
-// 	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c.* new", filename))
-// 	if result.Error != nil {
-// 		t.Error(result.Error)
-// 	}
-// 	expectedOutput := `b:
-//   c: {}
-//   d: another thing
-// `
-// 	test.AssertResult(t, expectedOutput, result.Output)
-// }

pkg/yqlib/all_at_once_evaluator.go

@@ -0,0 +1,45 @@
+package yqlib
+
+import "container/list"
+
+/**
+	Loads all yaml documents of all files given into memory, then runs the given expression once.
+**/
+type Evaluator interface {
+	EvaluateFiles(expression string, filenames []string, printer Printer) error
+}
+
+type allAtOnceEvaluator struct {
+	treeNavigator DataTreeNavigator
+	treeCreator   PathTreeCreator
+}
+
+func NewAllAtOnceEvaluator() Evaluator {
+	return &allAtOnceEvaluator{treeNavigator: NewDataTreeNavigator(), treeCreator: NewPathTreeCreator()}
+}
+
+func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string, printer Printer) error {
+	fileIndex := 0
+	node, err := treeCreator.ParsePath(expression)
+	if err != nil {
+		return err
+	}
+	var allDocuments *list.List = list.New()
+	for _, filename := range filenames {
+		reader, err := readStream(filename)
+		if err != nil {
+			return err
+		}
+		fileDocuments, err := readDocuments(reader, filename, fileIndex)
+		if err != nil {
+			return err
+		}
+		allDocuments.PushBackList(fileDocuments)
+		fileIndex = fileIndex + 1
+	}
+	matches, err := treeNavigator.GetMatchingNodes(allDocuments, node)
+	if err != nil {
+		return err
+	}
+	return printer.PrintResults(matches)
+}

pkg/yqlib/candidate_node.go

@@ -6,14 +6,15 @@ import (
 	"strings"
 
 	"github.com/jinzhu/copier"
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type CandidateNode struct {
-	Node     *yaml.Node    // the actual node
-	Path     []interface{} /// the path we took to get to this node
-	Document uint          // the document index of this node
-	Filename string
+	Node      *yaml.Node    // the actual node
+	Path      []interface{} /// the path we took to get to this node
+	Document  uint          // the document index of this node
+	Filename  string
+	FileIndex int
 }
 
 func (n *CandidateNode) GetKey() string {

pkg/yqlib/constants.go

@@ -1,5 +0,0 @@
-package yqlib
-
-import "gopkg.in/op/go-logging.v1"
-
-var log = logging.MustGetLogger("yq-lib")

pkg/yqlib/data_tree_navigator.go

@@ -5,17 +5,9 @@ import (
 
 	"container/list"
 
-	"gopkg.in/op/go-logging.v1"
+	logging "gopkg.in/op/go-logging.v1"
 )
 
-type dataTreeNavigator struct {
-	navigationPrefs NavigationPrefs
-}
-
-type NavigationPrefs struct {
-	FollowAlias bool
-}
-
 type DataTreeNavigator interface {
 	// given a list of CandidateEntities and a pathNode,
 	// this will process the list against the given pathNode and return
@@ -23,8 +15,11 @@ type DataTreeNavigator interface {
 	GetMatchingNodes(matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error)
 }
 
-func NewDataTreeNavigator(navigationPrefs NavigationPrefs) DataTreeNavigator {
-	return &dataTreeNavigator{navigationPrefs}
+type dataTreeNavigator struct {
+}
+
+func NewDataTreeNavigator() DataTreeNavigator {
+	return &dataTreeNavigator{}
 }
 
 func (d *dataTreeNavigator) GetMatchingNodes(matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {

pkg/yqlib/doc/.gitignore

@@ -0,0 +1 @@
+*.zip

pkg/yqlib/doc/Add.md

@@ -0,0 +1,133 @@
+Add behaves differently according to the type of the LHS:
+- arrays: concatenate
+- number scalars: arithmetic addition (soon)
+- string scalars: concatenate (soon)
+
+Use `+=` as append assign for things like increment. `.a += .x` is equivalent to running `.a |= . + .x`.
+
+## Concatenate and assign arrays
+Given a sample.yml file of:
+```yaml
+a:
+  val: thing
+  b:
+    - cat
+    - dog
+```
+then
+```bash
+yq eval '.a.b += ["cow"]' sample.yml
+```
+will output
+```yaml
+a:
+  val: thing
+  b:
+    - cat
+    - dog
+    - cow
+```
+
+## Concatenate arrays
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+b:
+  - 3
+  - 4
+```
+then
+```bash
+yq eval '.a + .b' sample.yml
+```
+will output
+```yaml
+- 1
+- 2
+- 3
+- 4
+```
+
+## Concatenate null to array
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+```
+then
+```bash
+yq eval '.a + null' sample.yml
+```
+will output
+```yaml
+- 1
+- 2
+```
+
+## Add object to array
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+c:
+  cat: meow
+```
+then
+```bash
+yq eval '.a + .c' sample.yml
+```
+will output
+```yaml
+- 1
+- 2
+- cat: meow
+```
+
+## Add string to array
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+```
+then
+```bash
+yq eval '.a + "hello"' sample.yml
+```
+will output
+```yaml
+- 1
+- 2
+- hello
+```
+
+## Update array (append)
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+b:
+  - 3
+  - 4
+```
+then
+```bash
+yq eval '.a = .a + .b' sample.yml
+```
+will output
+```yaml
+a:
+  - 1
+  - 2
+  - 3
+  - 4
+b:
+  - 3
+  - 4
+```
+

pkg/yqlib/doc/Assign.md

@@ -5,8 +5,19 @@ Which will assign the LHS node values to the RHS node values. The RHS expression
 
 ### relative form: `|=`
 This will do a similar thing to the plain form, however, the RHS expression is run against _the LHS nodes_. This is useful for updating values based on old values, e.g. increment.
-## Examples
-### Update parent to be the child value
+## Create yaml file
+Running
+```bash
+yq eval --null-input '(.a.b = "cat") | (.x = "frog")'
+```
+will output
+```yaml
+a:
+  b: cat
+x: frog
+```
+
+## Update node to be the child value
 Given a sample.yml file of:
 ```yaml
 a:
@@ -23,7 +34,7 @@ a:
   g: foof
 ```
 
-### Update to be the sibling value
+## Update node to be the sibling value
 Given a sample.yml file of:
 ```yaml
 a:
@@ -40,7 +51,7 @@ a: sibling
 b: sibling
 ```
 
-### Updated multiple paths
+## Updated multiple paths
 Given a sample.yml file of:
 ```yaml
 a: fieldA
@@ -58,7 +69,7 @@ b: fieldB
 c: potatoe
 ```
 
-### Update string value
+## Update string value
 Given a sample.yml file of:
 ```yaml
 a:
@@ -74,7 +85,7 @@ a:
   b: frog
 ```
 
-### Update string value via |=
+## Update string value via |=
 Note there is no difference between `=` and `|=` when the RHS is a scalar
 
 Given a sample.yml file of:
@@ -92,7 +103,7 @@ a:
   b: frog
 ```
 
-### Update selected results
+## Update selected results
 Given a sample.yml file of:
 ```yaml
 a:
@@ -101,7 +112,7 @@ a:
 ```
 then
 ```bash
-yq eval '.a[] | select(. == "apple") |= "frog"' sample.yml
+yq eval '.a.[] | select(. == "apple") |= "frog"' sample.yml
 ```
 will output
 ```yaml
@@ -110,7 +121,7 @@ a:
   c: cactus
 ```
 
-### Update array values
+## Update array values
 Given a sample.yml file of:
 ```yaml
 - candy
@@ -128,10 +139,10 @@ will output
 - bogs
 ```
 
-### Update empty object
+## Update empty object
 Given a sample.yml file of:
 ```yaml
-'': null
+{}
 ```
 then
 ```bash
@@ -139,25 +150,20 @@ yq eval '.a.b |= "bogs"' sample.yml
 ```
 will output
 ```yaml
-'': null
-a:
-  b: bogs
+{a: {b: bogs}}
 ```
 
-### Update empty object and array
+## Update empty object and array
 Given a sample.yml file of:
 ```yaml
-'': null
+{}
 ```
 then
 ```bash
-yq eval '.a.b[0] |= "bogs"' sample.yml
+yq eval '.a.b.[0] |= "bogs"' sample.yml
 ```
 will output
 ```yaml
-'': null
-a:
-  b:
-    - bogs
+{a: {b: [bogs]}}
 ```
 

pkg/yqlib/doc/Boolean Operators.md

@@ -0,0 +1,113 @@
+The `or` and `and` operators take two parameters and return a boolean result. `not` flips a boolean from true to false, or vice versa. These are most commonly used with the `select` operator to filter particular nodes.
+## OR example
+Running
+```bash
+yq eval --null-input 'true or false'
+```
+will output
+```yaml
+true
+```
+
+## AND example
+Running
+```bash
+yq eval --null-input 'true and false'
+```
+will output
+```yaml
+false
+```
+
+## Matching nodes with select, equals and or
+Given a sample.yml file of:
+```yaml
+- a: bird
+  b: dog
+- a: frog
+  b: bird
+- a: cat
+  b: fly
+```
+then
+```bash
+yq eval '[.[] | select(.a == "cat" or .b == "dog")]' sample.yml
+```
+will output
+```yaml
+- a: bird
+  b: dog
+- a: cat
+  b: fly
+```
+
+## Not true is false
+Running
+```bash
+yq eval --null-input 'true | not'
+```
+will output
+```yaml
+false
+```
+
+## Not false is true
+Running
+```bash
+yq eval --null-input 'false | not'
+```
+will output
+```yaml
+true
+```
+
+## String values considered to be true
+Running
+```bash
+yq eval --null-input '"cat" | not'
+```
+will output
+```yaml
+false
+```
+
+## Empty string value considered to be true
+Running
+```bash
+yq eval --null-input '"" | not'
+```
+will output
+```yaml
+false
+```
+
+## Numbers are considered to be true
+Running
+```bash
+yq eval --null-input '1 | not'
+```
+will output
+```yaml
+false
+```
+
+## Zero is considered to be true
+Running
+```bash
+yq eval --null-input '0 | not'
+```
+will output
+```yaml
+false
+```
+
+## Null is considered to be false
+Running
+```bash
+yq eval --null-input '~ | not'
+```
+will output
+```yaml
+true
+```
+

pkg/yqlib/doc/Collect into Array.md

@@ -3,17 +3,17 @@
 This creates an array using the expression between the square brackets.
 
 
-## Examples
-### Collect empty
+## Collect empty
 Running
 ```bash
 yq eval --null-input '[]'
 ```
 will output
 ```yaml
+[]
 ```
 
-### Collect single
+## Collect single
 Running
 ```bash
 yq eval --null-input '["cat"]'
@@ -23,7 +23,7 @@ will output
 - cat
 ```
 
-### Collect many
+## Collect many
 Given a sample.yml file of:
 ```yaml
 a: cat

pkg/yqlib/doc/Collect into Object.md

@@ -1,15 +1,15 @@
 This is used to construct objects (or maps). This can be used against existing yaml, or to create fresh yaml documents.
-## Examples
-### Collect empty object
+## Collect empty object
 Running
 ```bash
 yq eval --null-input '{}'
 ```
 will output
 ```yaml
+{}
 ```
 
-### Wrap (prefix) existing object
+## Wrap (prefix) existing object
 Given a sample.yml file of:
 ```yaml
 name: Mike
@@ -24,7 +24,7 @@ wrap:
   name: Mike
 ```
 
-### Using splat to create multiple objects
+## Using splat to create multiple objects
 Given a sample.yml file of:
 ```yaml
 name: Mike
@@ -34,7 +34,7 @@ pets:
 ```
 then
 ```bash
-yq eval '{.name: .pets[]}' sample.yml
+yq eval '{.name: .pets.[]}' sample.yml
 ```
 will output
 ```yaml
@@ -42,7 +42,7 @@ Mike: cat
 Mike: dog
 ```
 
-### Working with multiple documents
+## Working with multiple documents
 Given a sample.yml file of:
 ```yaml
 name: Mike
@@ -57,7 +57,7 @@ pets:
 ```
 then
 ```bash
-yq eval '{.name: .pets[]}' sample.yml
+yq eval '{.name: .pets.[]}' sample.yml
 ```
 will output
 ```yaml
@@ -67,7 +67,7 @@ Rosey: monkey
 Rosey: sheep
 ```
 
-### Creating yaml from scratch
+## Creating yaml from scratch
 Running
 ```bash
 yq eval --null-input '{"wrap": "frog"}'

pkg/yqlib/doc/Comment Operators.md

@@ -1,6 +1,5 @@
 Use these comment operators to set or retrieve comments.
-## Examples
-### Set line comment
+## Set line comment
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -14,7 +13,7 @@ will output
 a: cat # single
 ```
 
-### Set head comment
+## Set head comment
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -30,7 +29,7 @@ will output
 a: cat
 ```
 
-### Set foot comment, using an expression
+## Set foot comment, using an expression
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -46,7 +45,7 @@ a: cat
 # cat
 ```
 
-### Remove comment
+## Remove comment
 Given a sample.yml file of:
 ```yaml
 a: cat # comment
@@ -62,7 +61,7 @@ a: cat
 b: dog # leave this
 ```
 
-### Remove all comments
+## Remove all comments
 Given a sample.yml file of:
 ```yaml
 a: cat # comment
@@ -76,7 +75,7 @@ will output
 a: cat
 ```
 
-### Get line comment
+## Get line comment
 Given a sample.yml file of:
 ```yaml
 a: cat # meow
@@ -90,7 +89,7 @@ will output
 meow
 ```
 
-### Get head comment
+## Get head comment
 Given a sample.yml file of:
 ```yaml
 a: cat # meow
@@ -104,7 +103,7 @@ will output
 
 ```
 
-### Get foot comment
+## Get foot comment
 Given a sample.yml file of:
 ```yaml
 a: cat # meow

pkg/yqlib/doc/Delete.md

@@ -1,6 +1,5 @@
 Deletes matching entries in maps or arrays.
-## Examples
-### Delete entry in map
+## Delete entry in map
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -15,7 +14,7 @@ will output
 a: cat
 ```
 
-### Delete entry in array
+## Delete entry in array
 Given a sample.yml file of:
 ```yaml
 - 1
@@ -32,7 +31,7 @@ will output
 - 3
 ```
 
-### Delete no matches
+## Delete no matches
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -48,7 +47,7 @@ a: cat
 b: dog
 ```
 
-### Delete matching entries
+## Delete matching entries
 Given a sample.yml file of:
 ```yaml
 a: cat

pkg/yqlib/doc/Document Index.md

@@ -1,6 +1,5 @@
-
-## Examples
-### Retrieve a document index
+Use the `documentIndex` operator to select nodes of a particular document.
+## Retrieve a document index
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -18,7 +17,7 @@ will output
 1
 ```
 
-### Filter by document index
+## Filter by document index
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -34,7 +33,7 @@ will output
 a: frog
 ```
 
-### Print Document Index with matches
+## Print Document Index with matches
 Given a sample.yml file of:
 ```yaml
 a: cat

pkg/yqlib/doc/Equals.md

@@ -1,5 +1,3 @@
-## Equals Operator
-
 This is a boolean operator that will return ```true``` if the LHS is equal to the RHS and ``false`` otherwise.
 
 ```
@@ -13,8 +11,7 @@ select(.a == .b)
 ```
 
 
-## Examples
-### Match string
+## Match string
 Given a sample.yml file of:
 ```yaml
 - cat
@@ -32,7 +29,7 @@ true
 false
 ```
 
-### Match number
+## Match number
 Given a sample.yml file of:
 ```yaml
 - 3
@@ -50,7 +47,7 @@ true
 false
 ```
 
-### Match nulls
+## Match nulls
 Running
 ```bash
 yq eval --null-input 'null == ~'

pkg/yqlib/doc/Explode.md

@@ -1,6 +1,5 @@
 Explodes (or dereferences) aliases and anchors.
-## Examples
-### Explode alias and anchor
+## Explode alias and anchor
 Given a sample.yml file of:
 ```yaml
 f:
@@ -18,7 +17,7 @@ f:
   b: cat
 ```
 
-### Explode with no aliases or anchors
+## Explode with no aliases or anchors
 Given a sample.yml file of:
 ```yaml
 a: mike
@@ -32,7 +31,7 @@ will output
 a: mike
 ```
 
-### Explode with alias keys
+## Explode with alias keys
 Given a sample.yml file of:
 ```yaml
 f:
@@ -50,7 +49,7 @@ f:
   cat: b
 ```
 
-### Explode with merge anchors
+## Explode with merge anchors
 Given a sample.yml file of:
 ```yaml
 foo: &foo

pkg/yqlib/doc/File Operators.md

@@ -0,0 +1,35 @@
+File operators are most often used with merge when needing to merge specific files together. Note that when doing this, you will need to use `eval-all` to ensure all yaml documents are loaded into memory before performing the merge (as opposed to `eval` which runs the expression once per document).
+
+## Merging files
+Note the use of eval-all to ensure all documents are loaded into memory.
+```bash
+yq eval-all 'select(fileIndex == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
+```
+## Get filename
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval 'filename' sample.yml
+```
+will output
+```yaml
+sample.yaml
+```
+
+## Get file index
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval 'fileIndex' sample.yml
+```
+will output
+```yaml
+0
+```
+

pkg/yqlib/doc/Has.md

@@ -0,0 +1,44 @@
+This is operation that returns true if the key exists in a map (or index in an array), false otherwise.
+## Has map key
+Given a sample.yml file of:
+```yaml
+- a: yes
+- a: ~
+- a:
+- b: nope
+```
+then
+```bash
+yq eval '.[] | has("a")' sample.yml
+```
+will output
+```yaml
+true
+true
+true
+false
+```
+
+## Has array index
+Given a sample.yml file of:
+```yaml
+- []
+- [1]
+- [1, 2]
+- [1, null]
+- [1, 2, 3]
+
+```
+then
+```bash
+yq eval '.[] | has(1)' sample.yml
+```
+will output
+```yaml
+false
+false
+true
+true
+true
+```
+

pkg/yqlib/doc/Mulitply Operator.md

@@ -1,121 +0,0 @@
-# Mulitply Operator
-## Examples
-### Merge objects together
-sample.yml:
-```yaml
-{a: {also: me}, b: {also: {g: wizz}}}
-```
-Expression
-```bash
-yq '. * {"a":.b}' < sample.yml
-```
-Result
-```yaml
-{a: {also: {g: wizz}}, b: {also: {g: wizz}}}
-```
-### Merge keeps style of LHS
-sample.yml:
-```yaml
-a: {things: great}
-b:
-  also: "me"
-
-```
-Expression
-```bash
-yq '. * {"a":.b}' < sample.yml
-```
-Result
-```yaml
-a: {things: great, also: "me"}
-b:
-  also: "me"
-```
-### Merge arrays
-sample.yml:
-```yaml
-{a: [1,2,3], b: [3,4,5]}
-```
-Expression
-```bash
-yq '. * {"a":.b}' < sample.yml
-```
-Result
-```yaml
-{a: [3, 4, 5], b: [3, 4, 5]}
-```
-### Merge to prefix an element
-sample.yml:
-```yaml
-{a: cat, b: dog}
-```
-Expression
-```bash
-yq '. * {"a": {"c": .a}}' < sample.yml
-```
-Result
-```yaml
-{a: {c: cat}, b: dog}
-```
-### Merge with simple aliases
-sample.yml:
-```yaml
-{a: &cat {c: frog}, b: {f: *cat}, c: {g: thongs}}
-```
-Expression
-```bash
-yq '.c * .b' < sample.yml
-```
-Result
-```yaml
-{g: thongs, f: *cat}
-```
-### Merge does not copy anchor names
-sample.yml:
-```yaml
-{a: {c: &cat frog}, b: {f: *cat}, c: {g: thongs}}
-```
-Expression
-```bash
-yq '.c * .a' < sample.yml
-```
-Result
-```yaml
-{g: thongs, c: frog}
-```
-### Merge with merge anchors
-sample.yml:
-```yaml
-
-foo: &foo
-  a: foo_a
-  thing: foo_thing
-  c: foo_c
-
-bar: &bar
-  b: bar_b
-  thing: bar_thing
-  c: bar_c
-
-foobarList:
-  b: foobarList_b
-  <<: [*foo,*bar]
-  c: foobarList_c
-
-foobar:
-  c: foobar_c
-  <<: *foo
-  thing: foobar_thing
-
-```
-Expression
-```bash
-yq '.foobar * .foobarList' < sample.yml
-```
-Result
-```yaml
-c: foobarList_c
-<<: [*foo, *bar]
-thing: foobar_thing
-b: foobarList_b
-```

pkg/yqlib/doc/Multiply.md

@@ -2,9 +2,18 @@ Like the multiple operator in `jq`, depending on the operands, this multiply ope
 
 Upcoming versions of `yq` will add support for other types of multiplication (numbers, strings).
 
+To concatenate when merging objects, use the `*+` form (see examples below). This will recursively merge objects, appending arrays when it encounters them.
+
 Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
-## Examples
-### Merge objects together, returning merged result only
+
+## Merging files
+Note the use of eval-all to ensure all documents are loaded into memory.
+
+```bash
+yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
+```
+
+## Merge objects together, returning merged result only
 Given a sample.yml file of:
 ```yaml
 a:
@@ -27,7 +36,7 @@ fieldA: cat
 fieldB: dog
 ```
 
-### Merge objects together, returning parent object
+## Merge objects together, returning parent object
 Given a sample.yml file of:
 ```yaml
 a:
@@ -55,12 +64,13 @@ b:
   fieldB: dog
 ```
 
-### Merge keeps style of LHS
+## Merge keeps style of LHS
 Given a sample.yml file of:
 ```yaml
 a: {things: great}
 b:
   also: "me"
+
 ```
 then
 ```bash
@@ -73,7 +83,7 @@ b:
   also: "me"
 ```
 
-### Merge arrays
+## Merge arrays
 Given a sample.yml file of:
 ```yaml
 a:
@@ -101,7 +111,39 @@ b:
   - 5
 ```
 
-### Merge to prefix an element
+## Merge, appending arrays
+Given a sample.yml file of:
+```yaml
+a:
+  array:
+    - 1
+    - 2
+    - animal: dog
+  value: coconut
+b:
+  array:
+    - 3
+    - 4
+    - animal: cat
+  value: banana
+```
+then
+```bash
+yq eval '.a *+ .b' sample.yml
+```
+will output
+```yaml
+array:
+  - 1
+  - 2
+  - animal: dog
+  - 3
+  - 4
+  - animal: cat
+value: banana
+```
+
+## Merge to prefix an element
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -118,7 +160,7 @@ a:
 b: dog
 ```
 
-### Merge with simple aliases
+## Merge with simple aliases
 Given a sample.yml file of:
 ```yaml
 a: &cat
@@ -138,7 +180,7 @@ g: thongs
 f: *cat
 ```
 
-### Merge does not copy anchor names
+## Merge does not copy anchor names
 Given a sample.yml file of:
 ```yaml
 a:
@@ -158,7 +200,7 @@ g: thongs
 c: frog
 ```
 
-### Merge with merge anchors
+## Merge with merge anchors
 Given a sample.yml file of:
 ```yaml
 foo: &foo

pkg/yqlib/doc/Not Operator.md

@@ -1,72 +0,0 @@
-This is a boolean operator and will return `true` when given a `false` value (including null), and `false` otherwise.
-## Examples
-### Not true is false
-Running
-```bash
-yq eval --null-input 'true | not'
-```
-will output
-```yaml
-false
-```
-
-### Not false is true
-Running
-```bash
-yq eval --null-input 'false | not'
-```
-will output
-```yaml
-true
-```
-
-### String values considered to be true
-Running
-```bash
-yq eval --null-input '"cat" | not'
-```
-will output
-```yaml
-false
-```
-
-### Empty string value considered to be true
-Running
-```bash
-yq eval --null-input '"" | not'
-```
-will output
-```yaml
-false
-```
-
-### Numbers are considered to be true
-Running
-```bash
-yq eval --null-input '1 | not'
-```
-will output
-```yaml
-false
-```
-
-### Zero is considered to be true
-Running
-```bash
-yq eval --null-input '0 | not'
-```
-will output
-```yaml
-false
-```
-
-### Null is considered to be false
-Running
-```bash
-yq eval --null-input '~ | not'
-```
-will output
-```yaml
-true
-```
-

pkg/yqlib/doc/Path.md

@@ -0,0 +1,92 @@
+The path operator can be used to get the traversal paths of matching nodes in an expression. The path is returned as an array, which if traversed in order will lead to the matching node.
+
+You can get the key/index of matching nodes by using the `path` operator to return the path array then piping that through `.[-1]` to get the last element of that array, the key.
+
+## Map path
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a.b | path' sample.yml
+```
+will output
+```yaml
+- a
+- b
+```
+
+## Get map key
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a.b | path | .[-1]' sample.yml
+```
+will output
+```yaml
+b
+```
+
+## Array path
+Given a sample.yml file of:
+```yaml
+a:
+  - cat
+  - dog
+```
+then
+```bash
+yq eval '.a.[] | select(. == "dog") | path' sample.yml
+```
+will output
+```yaml
+- a
+- 1
+```
+
+## Get array index
+Given a sample.yml file of:
+```yaml
+a:
+  - cat
+  - dog
+```
+then
+```bash
+yq eval '.a.[] | select(. == "dog") | path | .[-1]' sample.yml
+```
+will output
+```yaml
+1
+```
+
+## Print path and value
+Given a sample.yml file of:
+```yaml
+a:
+  - cat
+  - dog
+  - frog
+```
+then
+```bash
+yq eval '.a.[] | select(. == "*og") | [{"path":path, "value":.}]' sample.yml
+```
+will output
+```yaml
+- path:
+    - a
+    - 1
+  value: dog
+- path:
+    - a
+    - 2
+  value: frog
+```
+

pkg/yqlib/doc/Recursive Descent.md

@@ -3,69 +3,7 @@ This operator recursively matches all children nodes given of a particular eleme
 ```bash
 yq eval '.. style= "flow"' file.yaml
 ```
-## Examples
-### Map
-Given a sample.yml file of:
-```yaml
-a:
-  b: apple
-```
-then
-```bash
-yq eval '..' sample.yml
-```
-will output
-```yaml
-a:
-  b: apple
-b: apple
-apple
-```
-
-### Array
-Given a sample.yml file of:
-```yaml
-- 1
-- 2
-- 3
-```
-then
-```bash
-yq eval '..' sample.yml
-```
-will output
-```yaml
-- 1
-- 2
-- 3
-1
-2
-3
-```
-
-### Array of maps
-Given a sample.yml file of:
-```yaml
-- a: cat
-- 2
-- true
-```
-then
-```bash
-yq eval '..' sample.yml
-```
-will output
-```yaml
-- a: cat
-- 2
-- true
-a: cat
-cat
-2
-true
-```
-
-### Aliases are not traversed
+## Aliases are not traversed
 Given a sample.yml file of:
 ```yaml
 a: &cat
@@ -74,20 +12,20 @@ b: *cat
 ```
 then
 ```bash
-yq eval '..' sample.yml
+yq eval '[..]' sample.yml
 ```
 will output
 ```yaml
-a: &cat
+- a: &cat
+    c: frog
+  b: *cat
+- &cat
   c: frog
-b: *cat
-&cat
-c: frog
-frog
-*cat
+- frog
+- *cat
 ```
 
-### Merge docs are not traversed
+## Merge docs are not traversed
 Given a sample.yml file of:
 ```yaml
 foo: &foo
@@ -111,15 +49,15 @@ foobar:
 ```
 then
 ```bash
-yq eval '.foobar | ..' sample.yml
+yq eval '.foobar | [..]' sample.yml
 ```
 will output
 ```yaml
-c: foobar_c
-!!merge <<: *foo
-thing: foobar_thing
-foobar_c
-*foo
-foobar_thing
+- c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+- foobar_c
+- *foo
+- foobar_thing
 ```
 

pkg/yqlib/doc/Select.md

@@ -1,6 +1,5 @@
 Select is used to filter arrays and maps by a boolean expression.
-## Examples
-### Select elements from array
+## Select elements from array
 Given a sample.yml file of:
 ```yaml
 - cat
@@ -17,7 +16,7 @@ cat
 goat
 ```
 
-### Select and update matching values in map
+## Select and update matching values in map
 Given a sample.yml file of:
 ```yaml
 a:
@@ -27,7 +26,7 @@ a:
 ```
 then
 ```bash
-yq eval '(.a[] | select(. == "*at")) |= "rabbit"' sample.yml
+yq eval '(.a.[] | select(. == "*at")) |= "rabbit"' sample.yml
 ```
 will output
 ```yaml

pkg/yqlib/doc/Sort Keys.md

@@ -0,0 +1,68 @@
+The Sort Keys operator sorts maps by their keys (based on their string value). This operator does not do anything to arrays or scalars (so you can easily recursively apply it to all maps).
+
+Sort is particularly useful for diffing two different yaml documents:
+
+```bash
+yq eval -i 'sortKeys(..)' file1.yml
+yq eval -i 'sortKeys(..)' file2.yml
+diff file1.yml file2.yml
+```
+
+## Sort keys of map
+Given a sample.yml file of:
+```yaml
+c: frog
+a: blah
+b: bing
+```
+then
+```bash
+yq eval 'sortKeys(.)' sample.yml
+```
+will output
+```yaml
+a: blah
+b: bing
+c: frog
+```
+
+## Sort keys recursively
+Note the array elements are left unsorted, but maps inside arrays are sorted
+
+Given a sample.yml file of:
+```yaml
+bParent:
+  c: dog
+  array:
+    - 3
+    - 1
+    - 2
+aParent:
+  z: donkey
+  x:
+    - c: yum
+      b: delish
+    - b: ew
+      a: apple
+```
+then
+```bash
+yq eval 'sortKeys(..)' sample.yml
+```
+will output
+```yaml
+aParent:
+  x:
+    - b: delish
+      c: yum
+    - a: apple
+      b: ew
+  z: donkey
+bParent:
+  array:
+    - 3
+    - 1
+    - 2
+  c: dog
+```
+

pkg/yqlib/doc/Style.md

@@ -1,6 +1,5 @@
 The style operator can be used to get or set the style of nodes (e.g. string style, yaml style)
-## Examples
-### Set tagged style
+## Set tagged style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -21,7 +20,7 @@ c: !!float 3.2
 e: !!bool true
 ```
 
-### Set double quote style
+## Set double quote style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -41,7 +40,7 @@ c: "3.2"
 e: "true"
 ```
 
-### Set single quote style
+## Set single quote style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -61,7 +60,7 @@ c: '3.2'
 e: 'true'
 ```
 
-### Set literal quote style
+## Set literal quote style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -85,7 +84,7 @@ e: |-
   true
 ```
 
-### Set folded quote style
+## Set folded quote style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -109,7 +108,7 @@ e: >-
   true
 ```
 
-### Set flow quote style
+## Set flow quote style
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -126,7 +125,9 @@ will output
 {a: cat, b: 5, c: 3.2, e: true}
 ```
 
-### Set empty (default) quote style
+## Pretty print
+Set empty (default) quote style
+
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -146,11 +147,10 @@ c: 3.2
 e: true
 ```
 
-### Read style
+## Read style
 Given a sample.yml file of:
 ```yaml
-a: cat
-b: thing
+{a: "cat", b: 'thing'}
 ```
 then
 ```bash
@@ -158,8 +158,8 @@ yq eval '.. | style' sample.yml
 ```
 will output
 ```yaml
-
-
-
+flow
+double
+single
 ```
 

pkg/yqlib/doc/Tag.md

@@ -1,6 +1,5 @@
-The tag operator can be used to get or set the tag of ndoes (e.g. `!!str`, `!!int`, `!!bool`).
-## Examples
-### Get tag
+The tag operator can be used to get or set the tag of nodes (e.g. `!!str`, `!!int`, `!!bool`).
+## Get tag
 Given a sample.yml file of:
 ```yaml
 a: cat
@@ -23,7 +22,7 @@ will output
 !!seq
 ```
 
-### Convert numbers to strings
+## Convert numbers to strings
 Given a sample.yml file of:
 ```yaml
 a: cat

pkg/yqlib/doc/Traverse.md

@@ -1,6 +1,5 @@
-This is the simples (and perhaps most used) operator, it is used to navigate deeply into yaml structurse.
-## Examples
-### Simple map navigation
+This is the simplest (and perhaps most used) operator, it is used to navigate deeply into yaml structurse.
+## Simple map navigation
 Given a sample.yml file of:
 ```yaml
 a:
@@ -15,7 +14,7 @@ will output
 b: apple
 ```
 
-### Splat
+## Splat
 Often used to pipe children into other operators
 
 Given a sample.yml file of:
@@ -33,7 +32,23 @@ b: apple
 c: banana
 ```
 
-### Children don't exist
+## Special characters
+Use quotes around path elements with special characters
+
+Given a sample.yml file of:
+```yaml
+"{}": frog
+```
+then
+```bash
+yq eval '."{}"' sample.yml
+```
+will output
+```yaml
+frog
+```
+
+## Children don't exist
 Nodes are added dynamically while traversing
 
 Given a sample.yml file of:
@@ -49,7 +64,7 @@ will output
 null
 ```
 
-### Wildcard matching
+## Wildcard matching
 Given a sample.yml file of:
 ```yaml
 a:
@@ -66,7 +81,7 @@ apple
 things
 ```
 
-### Aliases
+## Aliases
 Given a sample.yml file of:
 ```yaml
 a: &cat
@@ -82,7 +97,7 @@ will output
 *cat
 ```
 
-### Traversing aliases with splat
+## Traversing aliases with splat
 Given a sample.yml file of:
 ```yaml
 a: &cat
@@ -98,7 +113,7 @@ will output
 frog
 ```
 
-### Traversing aliases explicitly
+## Traversing aliases explicitly
 Given a sample.yml file of:
 ```yaml
 a: &cat
@@ -114,7 +129,7 @@ will output
 frog
 ```
 
-### Traversing arrays by index
+## Traversing arrays by index
 Given a sample.yml file of:
 ```yaml
 - 1
@@ -123,42 +138,42 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '[0]' sample.yml
+yq eval '.[0]' sample.yml
 ```
 will output
 ```yaml
 1
 ```
 
-### Maps with numeric keys
+## Maps with numeric keys
 Given a sample.yml file of:
 ```yaml
 2: cat
 ```
 then
 ```bash
-yq eval '[2]' sample.yml
+yq eval '.[2]' sample.yml
 ```
 will output
 ```yaml
 cat
 ```
 
-### Maps with non existing numeric keys
+## Maps with non existing numeric keys
 Given a sample.yml file of:
 ```yaml
 a: b
 ```
 then
 ```bash
-yq eval '[0]' sample.yml
+yq eval '.[0]' sample.yml
 ```
 will output
 ```yaml
 null
 ```
 
-### Traversing merge anchors
+## Traversing merge anchors
 Given a sample.yml file of:
 ```yaml
 foo: &foo
@@ -189,7 +204,7 @@ will output
 foo_a
 ```
 
-### Traversing merge anchors with override
+## Traversing merge anchors with override
 Given a sample.yml file of:
 ```yaml
 foo: &foo
@@ -220,7 +235,7 @@ will output
 foo_c
 ```
 
-### Traversing merge anchors with local override
+## Traversing merge anchors with local override
 Given a sample.yml file of:
 ```yaml
 foo: &foo
@@ -251,7 +266,7 @@ will output
 foobar_thing
 ```
 
-### Splatting merge anchors
+## Splatting merge anchors
 Given a sample.yml file of:
 ```yaml
 foo: &foo
@@ -284,7 +299,7 @@ foo_a
 foobar_thing
 ```
 
-### Traversing merge anchor lists
+## Traversing merge anchor lists
 Note that the later merge anchors override previous
 
 Given a sample.yml file of:
@@ -317,7 +332,7 @@ will output
 bar_thing
 ```
 
-### Splatting merge anchor lists
+## Splatting merge anchor lists
 Given a sample.yml file of:
 ```yaml
 foo: &foo

pkg/yqlib/doc/Union.md

@@ -1,6 +1,5 @@
 This operator is used to combine different results together.
-## Examples
-### Combine scalars
+## Combine scalars
 Running
 ```bash
 yq eval --null-input '1, true, "cat"'
@@ -12,7 +11,7 @@ true
 cat
 ```
 
-### Combine selected paths
+## Combine selected paths
 Given a sample.yml file of:
 ```yaml
 a: fieldA

pkg/yqlib/doc/headers/Add.md

@@ -0,0 +1,6 @@
+Add behaves differently according to the type of the LHS:
+- arrays: concatenate
+- number scalars: arithmetic addition (soon)
+- string scalars: concatenate (soon)
+
+Use `+=` as append assign for things like increment. `.a += .x` is equivalent to running `.a |= . + .x`.

pkg/yqlib/doc/headers/Boolean Operators.md

@@ -0,0 +1 @@
+The `or` and `and` operators take two parameters and return a boolean result. `not` flips a boolean from true to false, or vice versa. These are most commonly used with the `select` operator to filter particular nodes.

pkg/yqlib/doc/headers/Document Index.md

@@ -0,0 +1 @@
+Use the `documentIndex` operator to select nodes of a particular document.

pkg/yqlib/doc/headers/Equals.md

@@ -1,5 +1,3 @@
-## Equals Operator
-
 This is a boolean operator that will return ```true``` if the LHS is equal to the RHS and ``false`` otherwise.
 
 ```

pkg/yqlib/doc/headers/File Operators.md

@@ -0,0 +1,7 @@
+File operators are most often used with merge when needing to merge specific files together. Note that when doing this, you will need to use `eval-all` to ensure all yaml documents are loaded into memory before performing the merge (as opposed to `eval` which runs the expression once per document).
+
+## Merging files
+Note the use of eval-all to ensure all documents are loaded into memory.
+```bash
+yq eval-all 'select(fileIndex == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
+```

pkg/yqlib/doc/headers/Has.md

@@ -0,0 +1 @@
+This is operation that returns true if the key exists in a map (or index in an array), false otherwise.

pkg/yqlib/doc/headers/Multiply.md

@@ -2,4 +2,13 @@ Like the multiple operator in `jq`, depending on the operands, this multiply ope
 
 Upcoming versions of `yq` will add support for other types of multiplication (numbers, strings).
 
-Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
+To concatenate when merging objects, use the `*+` form (see examples below). This will recursively merge objects, appending arrays when it encounters them.
+
+Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
+
+## Merging files
+Note the use of eval-all to ensure all documents are loaded into memory.
+
+```bash
+yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
+```

pkg/yqlib/doc/headers/Not Operator.md

@@ -1 +0,0 @@
-This is a boolean operator and will return `true` when given a `false` value (including null), and `false` otherwise.

pkg/yqlib/doc/headers/Path.md

@@ -0,0 +1,3 @@
+The path operator can be used to get the traversal paths of matching nodes in an expression. The path is returned as an array, which if traversed in order will lead to the matching node.
+
+You can get the key/index of matching nodes by using the `path` operator to return the path array then piping that through `.[-1]` to get the last element of that array, the key.

pkg/yqlib/doc/headers/Sort Keys.md

@@ -0,0 +1,9 @@
+The Sort Keys operator sorts maps by their keys (based on their string value). This operator does not do anything to arrays or scalars (so you can easily recursively apply it to all maps).
+
+Sort is particularly useful for diffing two different yaml documents:
+
+```bash
+yq eval -i 'sortKeys(..)' file1.yml
+yq eval -i 'sortKeys(..)' file2.yml
+diff file1.yml file2.yml
+```

pkg/yqlib/doc/headers/Tag Operator.md

@@ -1 +0,0 @@
-The tag operator can be used to get or set the tag of ndoes (e.g. `!!str`, `!!int`, `!!bool`).

pkg/yqlib/doc/headers/Tag.md

@@ -0,0 +1 @@
+The tag operator can be used to get or set the tag of nodes (e.g. `!!str`, `!!int`, `!!bool`).

pkg/yqlib/doc/headers/Traverse Operator.md

@@ -1 +0,0 @@
-This is the simples (and perhaps most used) operator, it is used to navigate deeply into yaml structurse.

pkg/yqlib/doc/headers/Traverse.md

@@ -0,0 +1 @@
+This is the simplest (and perhaps most used) operator, it is used to navigate deeply into yaml structurse.

pkg/yqlib/encoder_test.go

@@ -32,7 +32,7 @@ func TestJsonEncoderPreservesObjectOrder(t *testing.T) {
 	writer := bufio.NewWriter(&output)
 
 	var jsonEncoder = NewJsonEncoder(writer, 2)
-	inputs, err := readDocuments(strings.NewReader(sampleYaml), "sample.yml")
+	inputs, err := readDocuments(strings.NewReader(sampleYaml), "sample.yml", 0)
 	if err != nil {
 		panic(err)
 	}

pkg/yqlib/file_utils.go

@@ -0,0 +1,50 @@
+package yqlib
+
+import (
+	"io"
+	"os"
+)
+
+func safelyRenameFile(from string, to string) {
+	if renameError := os.Rename(from, to); renameError != nil {
+		log.Debugf("Error renaming from %v to %v, attempting to copy contents", from, to)
+		log.Debug(renameError.Error())
+		// can't do this rename when running in docker to a file targeted in a mounted volume,
+		// so gracefully degrade to copying the entire contents.
+		if copyError := copyFileContents(from, to); copyError != nil {
+			log.Errorf("Failed copying from %v to %v", from, to)
+			log.Error(copyError.Error())
+		} else {
+			removeErr := os.Remove(from)
+			if removeErr != nil {
+				log.Errorf("failed removing original file: %s", from)
+			}
+		}
+	}
+}
+
+// thanks https://stackoverflow.com/questions/21060945/simple-way-to-copy-a-file-in-golang
+func copyFileContents(src, dst string) (err error) {
+	in, err := os.Open(src) // nolint gosec
+	if err != nil {
+		return err
+	}
+	defer safelyCloseFile(in)
+	out, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer safelyCloseFile(out)
+	if _, err = io.Copy(out, in); err != nil {
+		return err
+	}
+	return out.Sync()
+}
+
+func safelyCloseFile(file *os.File) {
+	err := file.Close()
+	if err != nil {
+		log.Error("Error closing file!")
+		log.Error(err.Error())
+	}
+}

pkg/yqlib/lib.go

@@ -9,6 +9,8 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
+var log = logging.MustGetLogger("yq-lib")
+
 type OperationType struct {
 	Type       string
 	NumArgs    uint // number of arguments to the op
@@ -17,15 +19,10 @@ type OperationType struct {
 }
 
 // operators TODO:
-// - get path operator (like doc index)
-// - get file index op (like doc index)
-// - get file name op (like doc index)
-// - write in place
-// - mergeAppend (merges and appends arrays)
+// - cookbook doc for common things
 // - mergeEmpty (sets only if the document is empty, do I do that now?)
 // - compare ??
 // - validate ??
-// - exists
 
 var Or = &OperationType{Type: "OR", NumArgs: 2, Precedence: 20, Handler: OrOperator}
 var And = &OperationType{Type: "AND", NumArgs: 2, Precedence: 20, Handler: AndOperator}
@@ -33,13 +30,15 @@ var And = &OperationType{Type: "AND", NumArgs: 2, Precedence: 20, Handler: AndOp
 var Union = &OperationType{Type: "UNION", NumArgs: 2, Precedence: 10, Handler: UnionOperator}
 
 var Assign = &OperationType{Type: "ASSIGN", NumArgs: 2, Precedence: 40, Handler: AssignUpdateOperator}
+var AddAssign = &OperationType{Type: "ADD_ASSIGN", NumArgs: 2, Precedence: 40, Handler: AddAssignOperator}
 
 var AssignAttributes = &OperationType{Type: "ASSIGN_ATTRIBUTES", NumArgs: 2, Precedence: 40, Handler: AssignAttributesOperator}
 var AssignStyle = &OperationType{Type: "ASSIGN_STYLE", NumArgs: 2, Precedence: 40, Handler: AssignStyleOperator}
 var AssignTag = &OperationType{Type: "ASSIGN_TAG", NumArgs: 2, Precedence: 40, Handler: AssignTagOperator}
 var AssignComment = &OperationType{Type: "ASSIGN_COMMENT", NumArgs: 2, Precedence: 40, Handler: AssignCommentsOperator}
 
-var Multiply = &OperationType{Type: "MULTIPLY", NumArgs: 2, Precedence: 40, Handler: MultiplyOperator}
+var Multiply = &OperationType{Type: "MULTIPLY", NumArgs: 2, Precedence: 45, Handler: MultiplyOperator}
+var Add = &OperationType{Type: "ADD", NumArgs: 2, Precedence: 45, Handler: AddOperator}
 
 var Equals = &OperationType{Type: "EQUALS", NumArgs: 2, Precedence: 40, Handler: EqualsOperator}
 var CreateMap = &OperationType{Type: "CREATE_MAP", NumArgs: 2, Precedence: 40, Handler: CreateMapOperator}
@@ -51,8 +50,12 @@ var GetStyle = &OperationType{Type: "GET_STYLE", NumArgs: 0, Precedence: 50, Han
 var GetTag = &OperationType{Type: "GET_TAG", NumArgs: 0, Precedence: 50, Handler: GetTagOperator}
 var GetComment = &OperationType{Type: "GET_COMMENT", NumArgs: 0, Precedence: 50, Handler: GetCommentsOperator}
 var GetDocumentIndex = &OperationType{Type: "GET_DOCUMENT_INDEX", NumArgs: 0, Precedence: 50, Handler: GetDocumentIndexOperator}
+var GetFilename = &OperationType{Type: "GET_FILENAME", NumArgs: 0, Precedence: 50, Handler: GetFilenameOperator}
+var GetFileIndex = &OperationType{Type: "GET_FILE_INDEX", NumArgs: 0, Precedence: 50, Handler: GetFileIndexOperator}
+var GetPath = &OperationType{Type: "GET_PATH", NumArgs: 0, Precedence: 50, Handler: GetPathOperator}
 
 var Explode = &OperationType{Type: "EXPLODE", NumArgs: 1, Precedence: 50, Handler: ExplodeOperator}
+var SortKeys = &OperationType{Type: "SORT_KEYS", NumArgs: 1, Precedence: 50, Handler: SortKeysOperator}
 
 var CollectObject = &OperationType{Type: "COLLECT_OBJECT", NumArgs: 0, Precedence: 50, Handler: CollectObjectOperator}
 var TraversePath = &OperationType{Type: "TRAVERSE_PATH", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
@@ -66,11 +69,9 @@ var Empty = &OperationType{Type: "EMPTY", NumArgs: 50, Handler: EmptyOperator}
 var RecursiveDescent = &OperationType{Type: "RECURSIVE_DESCENT", NumArgs: 0, Precedence: 50, Handler: RecursiveDescentOperator}
 
 var Select = &OperationType{Type: "SELECT", NumArgs: 1, Precedence: 50, Handler: SelectOperator}
+var Has = &OperationType{Type: "HAS", NumArgs: 1, Precedence: 50, Handler: HasOperator}
 var DeleteChild = &OperationType{Type: "DELETE", NumArgs: 1, Precedence: 40, Handler: DeleteChildOperator}
 
-// var Exists = &OperationType{Type: "Length", NumArgs: 2, Precedence: 35}
-// filters matches if they have the existing path
-
 type Operation struct {
 	OperationType *OperationType
 	Value         interface{}

pkg/yqlib/operator_add.go

@@ -0,0 +1,83 @@
+package yqlib
+
+import (
+	"fmt"
+
+	"container/list"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func createSelfAddOp(rhs *PathTreeNode) *PathTreeNode {
+	return &PathTreeNode{Operation: &Operation{OperationType: Add},
+		Lhs: &PathTreeNode{Operation: &Operation{OperationType: SelfReference}},
+		Rhs: rhs}
+}
+
+func AddAssignOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	assignmentOp := &Operation{OperationType: Assign}
+	assignmentOp.Preferences = &AssignOpPreferences{true}
+
+	assignmentOpNode := &PathTreeNode{Operation: assignmentOp, Lhs: pathNode.Lhs, Rhs: createSelfAddOp(pathNode.Rhs)}
+	return d.GetMatchingNodes(matchingNodes, assignmentOpNode)
+}
+
+func toNodes(candidates *list.List) []*yaml.Node {
+
+	if candidates.Len() == 0 {
+		return []*yaml.Node{}
+	}
+	candidate := candidates.Front().Value.(*CandidateNode)
+
+	if candidate.Node.Tag == "!!null" {
+		return []*yaml.Node{}
+	}
+
+	switch candidate.Node.Kind {
+	case yaml.SequenceNode:
+		return candidate.Node.Content
+	default:
+		return []*yaml.Node{candidate.Node}
+	}
+
+}
+
+func AddOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("Add operator")
+	var results = list.New()
+	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
+	if err != nil {
+		return nil, err
+	}
+	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
+
+	if err != nil {
+		return nil, err
+	}
+
+	for el := lhs.Front(); el != nil; el = el.Next() {
+		lhsCandidate := el.Value.(*CandidateNode)
+		lhsNode := UnwrapDoc(lhsCandidate.Node)
+
+		target := &CandidateNode{
+			Path:     lhsCandidate.Path,
+			Document: lhsCandidate.Document,
+			Filename: lhsCandidate.Filename,
+			Node:     &yaml.Node{},
+		}
+
+		switch lhsNode.Kind {
+		case yaml.MappingNode:
+			return nil, fmt.Errorf("Maps not yet supported for addition")
+		case yaml.SequenceNode:
+			target.Node.Kind = yaml.SequenceNode
+			target.Node.Style = lhsNode.Style
+			target.Node.Tag = "!!seq"
+			target.Node.Content = append(lhsNode.Content, toNodes(rhs)...)
+			results.PushBack(target)
+		case yaml.ScalarNode:
+			return nil, fmt.Errorf("Scalars not yet supported for addition")
+		}
+	}
+	return results, nil
+}

pkg/yqlib/operator_add_test.go

@@ -0,0 +1,63 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var addOperatorScenarios = []expressionScenario{
+	{
+		description: "Concatenate and assign arrays",
+		document:    `{a: {val: thing, b: [cat,dog]}}`,
+		expression:  ".a.b += [\"cow\"]",
+		expected: []string{
+			"D0, P[], (doc)::{a: {val: thing, b: [cat, dog, cow]}}\n",
+		},
+	},
+	{
+		description: "Concatenate arrays",
+		document:    `{a: [1,2], b: [3,4]}`,
+		expression:  `.a + .b`,
+		expected: []string{
+			"D0, P[a], (!!seq)::[1, 2, 3, 4]\n",
+		},
+	},
+	{
+		description: "Concatenate null to array",
+		document:    `{a: [1,2]}`,
+		expression:  `.a + null`,
+		expected: []string{
+			"D0, P[a], (!!seq)::[1, 2]\n",
+		},
+	},
+	{
+		description: "Add object to array",
+		document:    `{a: [1,2], c: {cat: meow}}`,
+		expression:  `.a + .c`,
+		expected: []string{
+			"D0, P[a], (!!seq)::[1, 2, {cat: meow}]\n",
+		},
+	},
+	{
+		description: "Add string to array",
+		document:    `{a: [1,2]}`,
+		expression:  `.a + "hello"`,
+		expected: []string{
+			"D0, P[a], (!!seq)::[1, 2, hello]\n",
+		},
+	},
+	{
+		description: "Update array (append)",
+		document:    `{a: [1,2], b: [3,4]}`,
+		expression:  `.a = .a + .b`,
+		expected: []string{
+			"D0, P[], (doc)::{a: [1, 2, 3, 4], b: [3, 4]}\n",
+		},
+	},
+}
+
+func TestAddOperatorScenarios(t *testing.T) {
+	for _, tt := range addOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "Add", addOperatorScenarios)
+}

pkg/yqlib/operator_assign.go

@@ -36,6 +36,11 @@ func AssignUpdateOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNo
 			candidate.UpdateFrom(first.Value.(*CandidateNode))
 		}
 	}
+	// // if there was nothing given, perhaps we are creating a new yaml doc
+	// if matchingNodes.Len() == 0 {
+	// 	log.Debug("started with nothing, returning LHS, %v", lhs.Len())
+	// 	return lhs, nil
+	// }
 	return matchingNodes, nil
 }
 

pkg/yqlib/operator_assign_test.go

@@ -6,7 +6,14 @@ import (
 
 var assignOperatorScenarios = []expressionScenario{
 	{
-		description: "Update parent to be the child value",
+		description: "Create yaml file",
+		expression:  `(.a.b = "cat") | (.x = "frog")`,
+		expected: []string{
+			"D0, P[], ()::a:\n    b: cat\nx: frog\n",
+		},
+	},
+	{
+		description: "Update node to be the child value",
 		document:    `{a: {b: {g: foof}}}`,
 		expression:  `.a |= .b`,
 		expected: []string{
@@ -14,7 +21,7 @@ var assignOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Update to be the sibling value",
+		description: "Update node to be the sibling value",
 		document:    `{a: {b: child}, b: sibling}`,
 		expression:  `.a = .b`,
 		expected: []string{
@@ -73,7 +80,7 @@ var assignOperatorScenarios = []expressionScenario{
 	{
 		description: "Update selected results",
 		document:    `{a: {b: apple, c: cactus}}`,
-		expression:  `.a[] | select(. == "apple") |= "frog"`,
+		expression:  `.a.[] | select(. == "apple") |= "frog"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: frog, c: cactus}}\n",
 		},
@@ -87,17 +94,19 @@ var assignOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Update empty object",
-		document:    `{}`,
-		expression:  `.a.b |= "bogs"`,
+		description:           "Update empty object",
+		dontFormatInputForDoc: true,
+		document:              `{}`,
+		expression:            `.a.b |= "bogs"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: bogs}}\n",
 		},
 	},
 	{
-		description: "Update empty object and array",
-		document:    `{}`,
-		expression:  `.a.b[0] |= "bogs"`,
+		description:           "Update empty object and array",
+		dontFormatInputForDoc: true,
+		document:              `{}`,
+		expression:            `.a.b.[0] |= "bogs"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: [bogs]}}\n",
 		},
@@ -105,7 +114,7 @@ var assignOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `{}`,
-		expression: `.a.b[1].c |= "bogs"`,
+		expression: `.a.b.[1].c |= "bogs"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: [null, {c: bogs}]}}\n",
 		},
@@ -116,5 +125,5 @@ func TestAssignOperatorScenarios(t *testing.T) {
 	for _, tt := range assignOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Assign Operator", assignOperatorScenarios)
+	documentScenarios(t, "Assign", assignOperatorScenarios)
 }

pkg/yqlib/operator_booleans.go

@@ -3,7 +3,7 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func isTruthy(c *CandidateNode) (bool, error) {
@@ -25,9 +25,42 @@ func isTruthy(c *CandidateNode) (bool, error) {
 
 type boolOp func(bool, bool) bool
 
+func performBoolOp(results *list.List, lhs *list.List, rhs *list.List, op boolOp) error {
+	for lhsChild := lhs.Front(); lhsChild != nil; lhsChild = lhsChild.Next() {
+		lhsCandidate := lhsChild.Value.(*CandidateNode)
+		lhsTrue, errDecoding := isTruthy(lhsCandidate)
+		if errDecoding != nil {
+			return errDecoding
+		}
+
+		for rhsChild := rhs.Front(); rhsChild != nil; rhsChild = rhsChild.Next() {
+			rhsCandidate := rhsChild.Value.(*CandidateNode)
+			rhsTrue, errDecoding := isTruthy(rhsCandidate)
+			if errDecoding != nil {
+				return errDecoding
+			}
+			boolResult := createBooleanCandidate(lhsCandidate, op(lhsTrue, rhsTrue))
+			results.PushBack(boolResult)
+		}
+	}
+	return nil
+}
+
 func booleanOp(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode, op boolOp) (*list.List, error) {
 	var results = list.New()
 
+	if matchingNodes.Len() == 0 {
+		lhs, err := d.GetMatchingNodes(list.New(), pathNode.Lhs)
+		if err != nil {
+			return nil, err
+		}
+		rhs, err := d.GetMatchingNodes(list.New(), pathNode.Rhs)
+		if err != nil {
+			return nil, err
+		}
+		return results, performBoolOp(results, lhs, rhs, op)
+	}
+
 	for el := matchingNodes.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		lhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Lhs)
@@ -39,23 +72,9 @@ func booleanOp(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTre
 			return nil, err
 		}
 
-		for lhsChild := lhs.Front(); lhsChild != nil; lhsChild = lhsChild.Next() {
-			lhsCandidate := lhsChild.Value.(*CandidateNode)
-			lhsTrue, errDecoding := isTruthy(lhsCandidate)
-			if errDecoding != nil {
-				return nil, errDecoding
-			}
-
-			for rhsChild := rhs.Front(); rhsChild != nil; rhsChild = rhsChild.Next() {
-				rhsCandidate := rhsChild.Value.(*CandidateNode)
-				rhsTrue, errDecoding := isTruthy(rhsCandidate)
-				if errDecoding != nil {
-					return nil, errDecoding
-				}
-				boolResult := createBooleanCandidate(lhsCandidate, op(lhsTrue, rhsTrue))
-
-				results.PushBack(boolResult)
-			}
+		err = performBoolOp(results, lhs, rhs, op)
+		if err != nil {
+			return nil, err
 		}
 
 	}
@@ -75,3 +94,20 @@ func AndOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathT
 		return b1 && b2
 	})
 }
+
+func NotOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("-- notOperation")
+	var results = list.New()
+
+	for el := matchMap.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		log.Debug("notOperation checking %v", candidate)
+		truthy, errDecoding := isTruthy(candidate)
+		if errDecoding != nil {
+			return nil, errDecoding
+		}
+		result := createBooleanCandidate(candidate, !truthy)
+		results.PushBack(result)
+	}
+	return results, nil
+}

pkg/yqlib/operator_booleans_test.go

@@ -6,18 +6,36 @@ import (
 
 var booleanOperatorScenarios = []expressionScenario{
 	{
-		document:   `{}`,
-		expression: `true or false`,
+		description: "OR example",
+		expression:  `true or false`,
 		expected: []string{
 			"D0, P[], (!!bool)::true\n",
 		},
-	}, {
-		document:   `{}`,
+	},
+	{
+		description: "AND example",
+		expression:  `true and false`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		document:    "[{a: bird, b: dog}, {a: frog, b: bird}, {a: cat, b: fly}]",
+		description: "Matching nodes with select, equals and or",
+		expression:  `[.[] | select(.a == "cat" or .b == "dog")]`,
+		expected: []string{
+			"D0, P[], (!!seq)::- {a: bird, b: dog}\n- {a: cat, b: fly}\n",
+		},
+	},
+	{
+		skipDoc:    true,
 		expression: `false or false`,
 		expected: []string{
 			"D0, P[], (!!bool)::false\n",
 		},
-	}, {
+	},
+	{
+		skipDoc:    true,
 		document:   `{a: true, b: false}`,
 		expression: `.[] or (false, true)`,
 		expected: []string{
@@ -27,10 +45,61 @@ var booleanOperatorScenarios = []expressionScenario{
 			"D0, P[b], (!!bool)::true\n",
 		},
 	},
+	{
+		description: "Not true is false",
+		expression:  `true | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Not false is true",
+		expression:  `false | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::true\n",
+		},
+	},
+	{
+		description: "String values considered to be true",
+		expression:  `"cat" | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Empty string value considered to be true",
+		expression:  `"" | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Numbers are considered to be true",
+		expression:  `1 | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+		description: "Zero is considered to be true",
+		expression:  `0 | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::false\n",
+		},
+	},
+	{
+
+		description: "Null is considered to be false",
+		expression:  `~ | not`,
+		expected: []string{
+			"D0, P[], (!!bool)::true\n",
+		},
+	},
 }
 
 func TestBooleanOperatorScenarios(t *testing.T) {
 	for _, tt := range booleanOperatorScenarios {
 		testScenario(t, &tt)
 	}
+	documentScenarios(t, "Boolean Operators", booleanOperatorScenarios)
 }

pkg/yqlib/operator_collect.go

@@ -3,12 +3,18 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func CollectOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	log.Debugf("-- collectOperation")
 
+	if matchMap.Len() == 0 {
+		node := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq", Value: "[]"}
+		candidate := &CandidateNode{Node: node}
+		return nodeToMap(candidate), nil
+	}
+
 	var results = list.New()
 
 	node := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}

pkg/yqlib/operator_collect_object.go

@@ -2,6 +2,8 @@ package yqlib
 
 import (
 	"container/list"
+
+	yaml "gopkg.in/yaml.v3"
 )
 
 /*
@@ -19,7 +21,9 @@ func CollectObjectOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *
 	log.Debugf("-- collectObjectOperation")
 
 	if matchMap.Len() == 0 {
-		return list.New(), nil
+		node := &yaml.Node{Kind: yaml.MappingNode, Tag: "!!map", Value: "{}"}
+		candidate := &CandidateNode{Node: node}
+		return nodeToMap(candidate), nil
 	}
 	first := matchMap.Front().Value.(*CandidateNode)
 	var rotated []*list.List = make([]*list.List, len(first.Node.Content))
@@ -90,7 +94,7 @@ func collect(d *dataTreeNavigator, aggregate *list.List, remainingMatches *list.
 
 			newCandidate.Path = nil
 
-			newCandidate, err = multiply(d, newCandidate, splatCandidate)
+			newCandidate, err = multiply(&MultiplyPreferences{AppendArrays: false})(d, newCandidate, splatCandidate)
 			if err != nil {
 				return nil, err
 			}

pkg/yqlib/operator_collect_object_test.go

@@ -9,7 +9,9 @@ var collectObjectOperatorScenarios = []expressionScenario{
 		description: `Collect empty object`,
 		document:    ``,
 		expression:  `{}`,
-		expected:    []string{},
+		expected: []string{
+			"D0, P[], (!!map)::{}\n",
+		},
 	},
 	{
 		description: `Wrap (prefix) existing object`,
@@ -39,7 +41,7 @@ var collectObjectOperatorScenarios = []expressionScenario{
 	{
 		description: `Using splat to create multiple objects`,
 		document:    `{name: Mike, pets: [cat, dog]}`,
-		expression:  `{.name: .pets[]}`,
+		expression:  `{.name: .pets.[]}`,
 		expected: []string{
 			"D0, P[], (!!map)::Mike: cat\n",
 			"D0, P[], (!!map)::Mike: dog\n",
@@ -49,7 +51,7 @@ var collectObjectOperatorScenarios = []expressionScenario{
 		description:           `Working with multiple documents`,
 		dontFormatInputForDoc: false,
 		document:              "{name: Mike, pets: [cat, dog]}\n---\n{name: Rosey, pets: [monkey, sheep]}",
-		expression:            `{.name: .pets[]}`,
+		expression:            `{.name: .pets.[]}`,
 		expected: []string{
 			"D0, P[], (!!map)::Mike: cat\n",
 			"D0, P[], (!!map)::Mike: dog\n",
@@ -60,7 +62,7 @@ var collectObjectOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `{name: Mike, pets: [cat, dog], food: [hotdog, burger]}`,
-		expression: `{.name: .pets[], "f":.food[]}`,
+		expression: `{.name: .pets.[], "f":.food.[]}`,
 		expected: []string{
 			"D0, P[], (!!map)::Mike: cat\nf: hotdog\n",
 			"D0, P[], (!!map)::Mike: cat\nf: burger\n",

pkg/yqlib/operator_collect_test.go

@@ -9,7 +9,17 @@ var collectOperatorScenarios = []expressionScenario{
 		description: "Collect empty",
 		document:    ``,
 		expression:  `[]`,
-		expected:    []string{},
+		expected: []string{
+			"D0, P[], (!!seq)::[]\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   ``,
+		expression: `[3]`,
+		expected: []string{
+			"D0, P[], (!!seq)::- 3\n",
+		},
 	},
 	{
 		description: "Collect single",
@@ -52,7 +62,7 @@ var collectOperatorScenarios = []expressionScenario{
 	},
 	{
 		document:   `a: {b: [1,2,3]}`,
-		expression: `[.a.b[]]`,
+		expression: `[.a.b.[]]`,
 		skipDoc:    true,
 		expected: []string{
 			"D0, P[a b], (!!seq)::- 1\n- 2\n- 3\n",

pkg/yqlib/operator_comments_test.go

@@ -75,5 +75,5 @@ func TestCommentOperatorScenarios(t *testing.T) {
 	for _, tt := range commentOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Comments Operator", commentOperatorScenarios)
+	documentScenarios(t, "Comment Operators", commentOperatorScenarios)
 }

pkg/yqlib/operator_create_map_test.go

@@ -21,14 +21,14 @@ var createMapOperatorScenarios = []expressionScenario{
 	},
 	{
 		document:   `{name: Mike, pets: [cat, dog]}`,
-		expression: `.name: .pets[]`,
+		expression: `.name: .pets.[]`,
 		expected: []string{
 			"D0, P[], (!!seq)::- [{Mike: cat}, {Mike: dog}]\n",
 		},
 	},
 	{
 		document:   `{name: Mike, pets: [cat, dog], food: [hotdog, burger]}`,
-		expression: `.name: .pets[], "f":.food[]`,
+		expression: `.name: .pets.[], "f":.food.[]`,
 		expected: []string{
 			"D0, P[], (!!seq)::- [{Mike: cat}, {Mike: dog}]\n",
 			"D0, P[], (!!seq)::- [{f: hotdog}, {f: burger}]\n",
@@ -36,7 +36,7 @@ var createMapOperatorScenarios = []expressionScenario{
 	},
 	{
 		document:   "{name: Mike, pets: [cat, dog], food: [hotdog, burger]}\n---\n{name: Fred, pets: [mouse], food: [pizza, onion, apple]}",
-		expression: `.name: .pets[], "f":.food[]`,
+		expression: `.name: .pets.[], "f":.food.[]`,
 		expected: []string{
 			"D0, P[], (!!seq)::- [{Mike: cat}, {Mike: dog}]\n- [{Fred: mouse}]\n",
 			"D0, P[], (!!seq)::- [{f: hotdog}, {f: burger}]\n- [{f: pizza}, {f: onion}, {f: apple}]\n",

pkg/yqlib/operator_delete_test.go

@@ -43,5 +43,5 @@ func TestDeleteOperatorScenarios(t *testing.T) {
 	for _, tt := range deleteOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Delete Operator", deleteOperatorScenarios)
+	documentScenarios(t, "Delete", deleteOperatorScenarios)
 }

pkg/yqlib/operator_document_index_test.go

@@ -37,5 +37,5 @@ func TestDocumentIndexScenarios(t *testing.T) {
 	for _, tt := range documentIndexScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Document Index Operator", documentIndexScenarios)
+	documentScenarios(t, "Document Index", documentIndexScenarios)
 }

pkg/yqlib/operator_equals_test.go

@@ -54,5 +54,5 @@ func TestEqualOperatorScenarios(t *testing.T) {
 	for _, tt := range equalsOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Equals Operator", equalsOperatorScenarios)
+	documentScenarios(t, "Equals", equalsOperatorScenarios)
 }

pkg/yqlib/operator_explode_test.go

@@ -86,5 +86,5 @@ func TestExplodeOperatorScenarios(t *testing.T) {
 	for _, tt := range explodeTest {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Explode Operator", explodeTest)
+	documentScenarios(t, "Explode", explodeTest)
 }

pkg/yqlib/operator_file.go

@@ -0,0 +1,38 @@
+package yqlib
+
+import (
+	"container/list"
+	"fmt"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func GetFilenameOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("GetFilename")
+
+	var results = list.New()
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		node := &yaml.Node{Kind: yaml.ScalarNode, Value: candidate.Filename, Tag: "!!str"}
+		lengthCand := &CandidateNode{Node: node, Document: candidate.Document, Path: candidate.Path}
+		results.PushBack(lengthCand)
+	}
+
+	return results, nil
+}
+
+func GetFileIndexOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("GetFileIndex")
+
+	var results = list.New()
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		node := &yaml.Node{Kind: yaml.ScalarNode, Value: fmt.Sprintf("%v", candidate.FileIndex), Tag: "!!int"}
+		lengthCand := &CandidateNode{Node: node, Document: candidate.Document, Path: candidate.Path}
+		results.PushBack(lengthCand)
+	}
+
+	return results, nil
+}

pkg/yqlib/operator_file_test.go

@@ -0,0 +1,31 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var fileOperatorScenarios = []expressionScenario{
+	{
+		description: "Get filename",
+		document:    `{a: cat}`,
+		expression:  `filename`,
+		expected: []string{
+			"D0, P[], (!!str)::sample.yml\n",
+		},
+	},
+	{
+		description: "Get file index",
+		document:    `{a: cat}`,
+		expression:  `fileIndex`,
+		expected: []string{
+			"D0, P[], (!!int)::0\n",
+		},
+	},
+}
+
+func TestFileOperatorsScenarios(t *testing.T) {
+	for _, tt := range fileOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "File Operators", fileOperatorScenarios)
+}

pkg/yqlib/operator_has.go

@@ -0,0 +1,53 @@
+package yqlib
+
+import (
+	"container/list"
+	"strconv"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func HasOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+
+	log.Debugf("-- hasOperation")
+	var results = list.New()
+
+	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
+	wanted := rhs.Front().Value.(*CandidateNode).Node
+	wantedKey := wanted.Value
+
+	if err != nil {
+		return nil, err
+	}
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+
+		// grab the first value
+		var contents = candidate.Node.Content
+		switch candidate.Node.Kind {
+		case yaml.MappingNode:
+			candidateHasKey := false
+			for index := 0; index < len(contents) && !candidateHasKey; index = index + 2 {
+				key := contents[index]
+				if key.Value == wantedKey {
+					candidateHasKey = true
+				}
+			}
+			results.PushBack(createBooleanCandidate(candidate, candidateHasKey))
+		case yaml.SequenceNode:
+			candidateHasKey := false
+			if wanted.Tag == "!!int" {
+				var number, errParsingInt = strconv.ParseInt(wantedKey, 10, 64) // nolint
+				if errParsingInt != nil {
+					return nil, errParsingInt
+				}
+				candidateHasKey = int64(len(contents)) > number
+			}
+			results.PushBack(createBooleanCandidate(candidate, candidateHasKey))
+		default:
+			results.PushBack(createBooleanCandidate(candidate, false))
+		}
+	}
+	return results, nil
+}

pkg/yqlib/operator_has_test.go

@@ -0,0 +1,48 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var hasOperatorScenarios = []expressionScenario{
+	{
+		description: "Has map key",
+		document: `- a: "yes"
+- a: ~
+- a: 
+- b: nope
+`,
+		expression: `.[] | has("a")`,
+		expected: []string{
+			"D0, P[0], (!!bool)::true\n",
+			"D0, P[1], (!!bool)::true\n",
+			"D0, P[2], (!!bool)::true\n",
+			"D0, P[3], (!!bool)::false\n",
+		},
+	},
+	{
+		dontFormatInputForDoc: true,
+		description:           "Has array index",
+		document: `- []
+- [1]
+- [1, 2]
+- [1, null]
+- [1, 2, 3]
+`,
+		expression: `.[] | has(1)`,
+		expected: []string{
+			"D0, P[0], (!!bool)::false\n",
+			"D0, P[1], (!!bool)::false\n",
+			"D0, P[2], (!!bool)::true\n",
+			"D0, P[3], (!!bool)::true\n",
+			"D0, P[4], (!!bool)::true\n",
+		},
+	},
+}
+
+func TestHasOperatorScenarios(t *testing.T) {
+	for _, tt := range hasOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "Has", hasOperatorScenarios)
+}

pkg/yqlib/operator_multiply.go

@@ -5,7 +5,7 @@ import (
 
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type CrossFunctionCalculation func(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error)
@@ -15,12 +15,14 @@ func crossFunction(d *dataTreeNavigator, matchingNodes *list.List, pathNode *Pat
 	if err != nil {
 		return nil, err
 	}
+	log.Debugf("crossFunction LHS len: %v", lhs.Len())
 
 	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 
 	if err != nil {
 		return nil, err
 	}
+	log.Debugf("crossFunction RHS len: %v", rhs.Len())
 
 	var results = list.New()
 
@@ -28,6 +30,7 @@ func crossFunction(d *dataTreeNavigator, matchingNodes *list.List, pathNode *Pat
 		lhsCandidate := el.Value.(*CandidateNode)
 
 		for rightEl := rhs.Front(); rightEl != nil; rightEl = rightEl.Next() {
+			log.Debugf("Applying calc")
 			rhsCandidate := rightEl.Value.(*CandidateNode)
 			resultCandidate, err := calculation(d, lhsCandidate, rhsCandidate)
 			if err != nil {
@@ -40,39 +43,49 @@ func crossFunction(d *dataTreeNavigator, matchingNodes *list.List, pathNode *Pat
 	return results, nil
 }
 
+type MultiplyPreferences struct {
+	AppendArrays bool
+}
+
 func MultiplyOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	log.Debugf("-- MultiplyOperator")
-	return crossFunction(d, matchingNodes, pathNode, multiply)
+	return crossFunction(d, matchingNodes, pathNode, multiply(pathNode.Operation.Preferences.(*MultiplyPreferences)))
 }
 
-func multiply(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
-	lhs.Node = UnwrapDoc(lhs.Node)
-	rhs.Node = UnwrapDoc(rhs.Node)
-	log.Debugf("Multipling LHS: %v", NodeToString(lhs))
-	log.Debugf("-          RHS: %v", NodeToString(rhs))
+func multiply(preferences *MultiplyPreferences) func(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
+	return func(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
+		lhs.Node = UnwrapDoc(lhs.Node)
+		rhs.Node = UnwrapDoc(rhs.Node)
+		log.Debugf("Multipling LHS: %v", lhs.Node.Tag)
+		log.Debugf("-          RHS: %v", rhs.Node.Tag)
 
-	if lhs.Node.Kind == yaml.MappingNode && rhs.Node.Kind == yaml.MappingNode ||
-		(lhs.Node.Kind == yaml.SequenceNode && rhs.Node.Kind == yaml.SequenceNode) {
+		shouldAppendArrays := preferences.AppendArrays
+
+		if lhs.Node.Kind == yaml.MappingNode && rhs.Node.Kind == yaml.MappingNode ||
+			(lhs.Node.Kind == yaml.SequenceNode && rhs.Node.Kind == yaml.SequenceNode) {
+
+			var newBlank = &CandidateNode{
+				Path:     lhs.Path,
+				Document: lhs.Document,
+				Filename: lhs.Filename,
+				Node:     &yaml.Node{},
+			}
+			var newThing, err = mergeObjects(d, newBlank, lhs, false)
+			if err != nil {
+				return nil, err
+			}
+			return mergeObjects(d, newThing, rhs, shouldAppendArrays)
 
-		var newBlank = &CandidateNode{
-			Path:     lhs.Path,
-			Document: lhs.Document,
-			Filename: lhs.Filename,
-			Node:     &yaml.Node{},
 		}
-		var newThing, err = mergeObjects(d, newBlank, lhs)
-		if err != nil {
-			return nil, err
-		}
-		return mergeObjects(d, newThing, rhs)
-
+		return nil, fmt.Errorf("Cannot multiply %v with %v", lhs.Node.Tag, rhs.Node.Tag)
 	}
-	return nil, fmt.Errorf("Cannot multiply %v with %v", NodeToString(lhs), NodeToString(rhs))
 }
 
-func mergeObjects(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
+func mergeObjects(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode, shouldAppendArrays bool) (*CandidateNode, error) {
 	var results = list.New()
-	err := recursiveDecent(d, results, nodeToMap(rhs))
+
+	// shouldn't recurse arrays if appending
+	err := recursiveDecent(d, results, nodeToMap(rhs), !shouldAppendArrays)
 	if err != nil {
 		return nil, err
 	}
@@ -83,7 +96,7 @@ func mergeObjects(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode)
 	}
 
 	for el := results.Front(); el != nil; el = el.Next() {
-		err := applyAssignment(d, pathIndexToStartFrom, lhs, el.Value.(*CandidateNode))
+		err := applyAssignment(d, pathIndexToStartFrom, lhs, el.Value.(*CandidateNode), shouldAppendArrays)
 		if err != nil {
 			return nil, err
 		}
@@ -104,7 +117,8 @@ func createTraversalTree(path []interface{}) *PathTreeNode {
 
 }
 
-func applyAssignment(d *dataTreeNavigator, pathIndexToStartFrom int, lhs *CandidateNode, rhs *CandidateNode) error {
+func applyAssignment(d *dataTreeNavigator, pathIndexToStartFrom int, lhs *CandidateNode, rhs *CandidateNode, shouldAppendArrays bool) error {
+
 	log.Debugf("merge - applyAssignment lhs %v, rhs: %v", NodeToString(lhs), NodeToString(rhs))
 
 	lhsPath := rhs.Path[pathIndexToStartFrom:]
@@ -113,6 +127,8 @@ func applyAssignment(d *dataTreeNavigator, pathIndexToStartFrom int, lhs *Candid
 	if rhs.Node.Kind == yaml.ScalarNode || rhs.Node.Kind == yaml.AliasNode {
 		assignmentOp.OperationType = Assign
 		assignmentOp.Preferences = &AssignOpPreferences{false}
+	} else if shouldAppendArrays && rhs.Node.Kind == yaml.SequenceNode {
+		assignmentOp.OperationType = AddAssign
 	}
 	rhsOp := &Operation{OperationType: ValueOp, CandidateNode: rhs}
 

pkg/yqlib/operator_multiply_test.go

@@ -13,6 +13,13 @@ var multiplyOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::{a: {also: me}, b: {also: me}}\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		expression: `{} * {"cat":"dog"}`,
+		expected: []string{
+			"D0, P[], (!!map)::cat: dog\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `{a: {also: me}, b: {also: [1]}}`,
@@ -92,6 +99,22 @@ b:
 			"D0, P[], (!!map)::{a: [3, 4, 5], b: [3, 4, 5]}\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `{a: [1], b: [2]}`,
+		expression: `.a *+ .b`,
+		expected: []string{
+			"D0, P[a], (!!seq)::[1, 2]\n",
+		},
+	},
+	{
+		description: "Merge, appending arrays",
+		document:    `{a: {array: [1, 2, animal: dog], value: coconut}, b: {array: [3, 4, animal: cat], value: banana}}`,
+		expression:  `.a *+ .b`,
+		expected: []string{
+			"D0, P[a], (!!map)::{array: [1, 2, {animal: dog}, 3, 4, {animal: cat}], value: banana}\n",
+		},
+	},
 	{
 		description: "Merge to prefix an element",
 		document:    `{a: cat, b: dog}`,
@@ -130,5 +153,5 @@ func TestMultiplyOperatorScenarios(t *testing.T) {
 	for _, tt := range multiplyOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Multiply Operator", multiplyOperatorScenarios)
+	documentScenarios(t, "Multiply", multiplyOperatorScenarios)
 }

pkg/yqlib/operator_not.go

@@ -1,20 +0,0 @@
-package yqlib
-
-import "container/list"
-
-func NotOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
-	log.Debugf("-- notOperation")
-	var results = list.New()
-
-	for el := matchMap.Front(); el != nil; el = el.Next() {
-		candidate := el.Value.(*CandidateNode)
-		log.Debug("notOperation checking %v", candidate)
-		truthy, errDecoding := isTruthy(candidate)
-		if errDecoding != nil {
-			return nil, errDecoding
-		}
-		result := createBooleanCandidate(candidate, !truthy)
-		results.PushBack(result)
-	}
-	return results, nil
-}

pkg/yqlib/operator_not_test.go

@@ -1,65 +0,0 @@
-package yqlib
-
-import (
-	"testing"
-)
-
-var notOperatorScenarios = []expressionScenario{
-	{
-		description: "Not true is false",
-		expression:  `true | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Not false is true",
-		expression:  `false | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::true\n",
-		},
-	},
-	{
-		description: "String values considered to be true",
-		expression:  `"cat" | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Empty string value considered to be true",
-		expression:  `"" | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Numbers are considered to be true",
-		expression:  `1 | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-		description: "Zero is considered to be true",
-		expression:  `0 | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::false\n",
-		},
-	},
-	{
-
-		description: "Null is considered to be false",
-		expression:  `~ | not`,
-		expected: []string{
-			"D0, P[], (!!bool)::true\n",
-		},
-	},
-}
-
-func TestNotOperatorScenarios(t *testing.T) {
-	for _, tt := range notOperatorScenarios {
-		testScenario(t, &tt)
-	}
-	documentScenarios(t, "Not Operator", notOperatorScenarios)
-}

pkg/yqlib/operator_path.go

@@ -0,0 +1,39 @@
+package yqlib
+
+import (
+	"container/list"
+	"fmt"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func createPathNodeFor(pathElement interface{}) *yaml.Node {
+	switch pathElement := pathElement.(type) {
+	case string:
+		return &yaml.Node{Kind: yaml.ScalarNode, Value: pathElement, Tag: "!!str"}
+	default:
+		return &yaml.Node{Kind: yaml.ScalarNode, Value: fmt.Sprintf("%v", pathElement), Tag: "!!int"}
+	}
+}
+
+func GetPathOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	log.Debugf("GetPath")
+
+	var results = list.New()
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		node := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}
+
+		content := make([]*yaml.Node, len(candidate.Path))
+		for pathIndex := 0; pathIndex < len(candidate.Path); pathIndex++ {
+			path := candidate.Path[pathIndex]
+			content[pathIndex] = createPathNodeFor(path)
+		}
+		node.Content = content
+		lengthCand := &CandidateNode{Node: node, Document: candidate.Document, Path: candidate.Path}
+		results.PushBack(lengthCand)
+	}
+
+	return results, nil
+}

pkg/yqlib/operator_path_test.go

@@ -0,0 +1,61 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var pathOperatorScenarios = []expressionScenario{
+	{
+		description: "Map path",
+		document:    `{a: {b: cat}}`,
+		expression:  `.a.b | path`,
+		expected: []string{
+			"D0, P[a b], (!!seq)::- a\n- b\n",
+		},
+	},
+	{
+		description: "Get map key",
+		document:    `{a: {b: cat}}`,
+		expression:  `.a.b | path | .[-1]`,
+		expected: []string{
+			"D0, P[a b -1], (!!str)::b\n",
+		},
+	},
+	{
+		description: "Array path",
+		document:    `{a: [cat, dog]}`,
+		expression:  `.a.[] | select(. == "dog") | path`,
+		expected: []string{
+			"D0, P[a 1], (!!seq)::- a\n- 1\n",
+		},
+	},
+	{
+		description: "Get array index",
+		document:    `{a: [cat, dog]}`,
+		expression:  `.a.[] | select(. == "dog") | path | .[-1]`,
+		expected: []string{
+			"D0, P[a 1 -1], (!!int)::1\n",
+		},
+	},
+	{
+		description: "Print path and value",
+		document:    `{a: [cat, dog, frog]}`,
+		expression:  `.a.[] | select(. == "*og") | [{"path":path, "value":.}]`,
+		expected: []string{`D0, P[], (!!seq)::- path:
+    - a
+    - 1
+  value: dog
+- path:
+    - a
+    - 2
+  value: frog
+`},
+	},
+}
+
+func TestPathOperatorsScenarios(t *testing.T) {
+	for _, tt := range pathOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "Path", pathOperatorScenarios)
+}

pkg/yqlib/operator_recursive_descent.go

@@ -3,13 +3,13 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func RecursiveDescentOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	var results = list.New()
 
-	err := recursiveDecent(d, results, matchMap)
+	err := recursiveDecent(d, results, matchMap, true)
 	if err != nil {
 		return nil, err
 	}
@@ -17,7 +17,7 @@ func RecursiveDescentOperator(d *dataTreeNavigator, matchMap *list.List, pathNod
 	return results, nil
 }
 
-func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.List) error {
+func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.List, recurseArray bool) error {
 	for el := matchMap.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 
@@ -26,14 +26,15 @@ func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.Li
 		log.Debugf("Recursive Decent, added %v", NodeToString(candidate))
 		results.PushBack(candidate)
 
-		if candidate.Node.Kind != yaml.AliasNode {
+		if candidate.Node.Kind != yaml.AliasNode && len(candidate.Node.Content) > 0 &&
+			(recurseArray || candidate.Node.Kind != yaml.SequenceNode) {
 
 			children, err := Splat(d, nodeToMap(candidate))
 
 			if err != nil {
 				return err
 			}
-			err = recursiveDecent(d, results, children)
+			err = recursiveDecent(d, results, children, recurseArray)
 			if err != nil {
 				return err
 			}

pkg/yqlib/operator_recursive_descent_test.go

@@ -5,6 +5,22 @@ import (
 )
 
 var recursiveDescentOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		document:   `{}`,
+		expression: `..`,
+		expected: []string{
+			"D0, P[], (!!map)::{}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `[]`,
+		expression: `..`,
+		expected: []string{
+			"D0, P[], (!!seq)::[]\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `cat`,
@@ -23,9 +39,9 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Map",
-		document:    `{a: {b: apple}}`,
-		expression:  `..`,
+		skipDoc:    true,
+		document:   `{a: {b: apple}}`,
+		expression: `..`,
 		expected: []string{
 			"D0, P[], (!!map)::{a: {b: apple}}\n",
 			"D0, P[a], (!!map)::{b: apple}\n",
@@ -33,9 +49,9 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Array",
-		document:    `[1,2,3]`,
-		expression:  `..`,
+		skipDoc:    true,
+		document:   `[1,2,3]`,
+		expression: `..`,
 		expected: []string{
 			"D0, P[], (!!seq)::[1, 2, 3]\n",
 			"D0, P[0], (!!int)::1\n",
@@ -44,9 +60,9 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Array of maps",
-		document:    `[{a: cat},2,true]`,
-		expression:  `..`,
+		skipDoc:    true,
+		document:   `[{a: cat},2,true]`,
+		expression: `..`,
 		expected: []string{
 			"D0, P[], (!!seq)::[{a: cat}, 2, true]\n",
 			"D0, P[0], (!!map)::{a: cat}\n",
@@ -58,23 +74,17 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 	{
 		description: "Aliases are not traversed",
 		document:    `{a: &cat {c: frog}, b: *cat}`,
-		expression:  `..`,
+		expression:  `[..]`,
 		expected: []string{
-			"D0, P[], (!!map)::{a: &cat {c: frog}, b: *cat}\n",
-			"D0, P[a], (!!map)::&cat {c: frog}\n",
-			"D0, P[a c], (!!str)::frog\n",
-			"D0, P[b], (alias)::*cat\n",
+			"D0, P[a], (!!seq)::- {a: &cat {c: frog}, b: *cat}\n- &cat {c: frog}\n- frog\n- *cat\n",
 		},
 	},
 	{
 		description: "Merge docs are not traversed",
 		document:    mergeDocSample,
-		expression:  `.foobar | ..`,
+		expression:  `.foobar | [..]`,
 		expected: []string{
-			"D0, P[foobar], (!!map)::c: foobar_c\n!!merge <<: *foo\nthing: foobar_thing\n",
-			"D0, P[foobar c], (!!str)::foobar_c\n",
-			"D0, P[foobar <<], (alias)::*foo\n",
-			"D0, P[foobar thing], (!!str)::foobar_thing\n",
+			"D0, P[foobar], (!!seq)::- c: foobar_c\n  !!merge <<: *foo\n  thing: foobar_thing\n- foobar_c\n- *foo\n- foobar_thing\n",
 		},
 	},
 	{
@@ -96,5 +106,5 @@ func TestRecursiveDescentOperatorScenarios(t *testing.T) {
 	for _, tt := range recursiveDescentOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Recursive Descent Operator", recursiveDescentOperatorScenarios)
+	documentScenarios(t, "Recursive Descent", recursiveDescentOperatorScenarios)
 }

pkg/yqlib/operator_select_test.go

@@ -23,7 +23,7 @@ var selectOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `a: [cat,goat,dog]`,
-		expression: `.a[] | select(. == "*at")`,
+		expression: `.a.[] | select(. == "*at")`,
 		expected: []string{
 			"D0, P[a 0], (!!str)::cat\n",
 			"D0, P[a 1], (!!str)::goat\n"},
@@ -31,7 +31,7 @@ var selectOperatorScenarios = []expressionScenario{
 	{
 		description: "Select and update matching values in map",
 		document:    `a: { things: cat, bob: goat, horse: dog }`,
-		expression:  `(.a[] | select(. == "*at")) |= "rabbit"`,
+		expression:  `(.a.[] | select(. == "*at")) |= "rabbit"`,
 		expected: []string{
 			"D0, P[], (doc)::a: {things: rabbit, bob: rabbit, horse: dog}\n",
 		},
@@ -39,7 +39,7 @@ var selectOperatorScenarios = []expressionScenario{
 	{
 		skipDoc:    true,
 		document:   `a: { things: {include: true}, notMe: {include: false}, andMe: {include: fold} }`,
-		expression: `.a[] | select(.include)`,
+		expression: `.a.[] | select(.include)`,
 		expected: []string{
 			"D0, P[a things], (!!map)::{include: true}\n",
 			"D0, P[a andMe], (!!map)::{include: fold}\n",
@@ -59,5 +59,5 @@ func TestSelectOperatorScenarios(t *testing.T) {
 	for _, tt := range selectOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Select Operator", selectOperatorScenarios)
+	documentScenarios(t, "Select", selectOperatorScenarios)
 }

pkg/yqlib/operator_sort_keys.go

@@ -0,0 +1,53 @@
+package yqlib
+
+import (
+	"container/list"
+	"sort"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func SortKeysOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+		if err != nil {
+			return nil, err
+		}
+
+		for childEl := rhs.Front(); childEl != nil; childEl = childEl.Next() {
+			node := UnwrapDoc(childEl.Value.(*CandidateNode).Node)
+			if node.Kind == yaml.MappingNode {
+				sortKeys(node)
+			}
+			if err != nil {
+				return nil, err
+			}
+		}
+
+	}
+	return matchingNodes, nil
+}
+
+func sortKeys(node *yaml.Node) {
+	keys := make([]string, len(node.Content)/2)
+	keyBucket := map[string]*yaml.Node{}
+	valueBucket := map[string]*yaml.Node{}
+	var contents = node.Content
+	for index := 0; index < len(contents); index = index + 2 {
+		key := contents[index]
+		value := contents[index+1]
+		keys[index/2] = key.Value
+		keyBucket[key.Value] = key
+		valueBucket[key.Value] = value
+	}
+	sort.Strings(keys)
+	sortedContent := make([]*yaml.Node, len(node.Content))
+	for index := 0; index < len(keys); index = index + 1 {
+		keyString := keys[index]
+		sortedContent[index*2] = keyBucket[keyString]
+		sortedContent[1+(index*2)] = valueBucket[keyString]
+	}
+	node.Content = sortedContent
+}

pkg/yqlib/operator_sort_keys_test.go

@@ -0,0 +1,32 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var sortKeysOperatorScenarios = []expressionScenario{
+	{
+		description: "Sort keys of map",
+		document:    `{c: frog, a: blah, b: bing}`,
+		expression:  `sortKeys(.)`,
+		expected: []string{
+			"D0, P[], (doc)::{a: blah, b: bing, c: frog}\n",
+		},
+	},
+	{
+		description:    "Sort keys recursively",
+		subdescription: "Note the array elements are left unsorted, but maps inside arrays are sorted",
+		document:       `{bParent: {c: dog, array: [3,1,2]}, aParent: {z: donkey, x: [{c: yum, b: delish}, {b: ew, a: apple}]}}`,
+		expression:     `sortKeys(..)`,
+		expected: []string{
+			"D0, P[], (!!map)::{aParent: {x: [{b: delish, c: yum}, {a: apple, b: ew}], z: donkey}, bParent: {array: [3, 1, 2], c: dog}}\n",
+		},
+	},
+}
+
+func TestSortKeysOperatorScenarios(t *testing.T) {
+	for _, tt := range sortKeysOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentScenarios(t, "Sort Keys", sortKeysOperatorScenarios)
+}

pkg/yqlib/operator_style_test.go

@@ -70,9 +70,10 @@ e: >-
 		},
 	},
 	{
-		description: "Set empty (default) quote style",
-		document:    `{a: cat, b: 5, c: 3.2, e: true}`,
-		expression:  `.. style=""`,
+		description:    "Pretty print",
+		subdescription: "Set empty (default) quote style",
+		document:       `{a: cat, b: 5, c: 3.2, e: true}`,
+		expression:     `.. style=""`,
 		expected: []string{
 			"D0, P[], (!!map)::a: cat\nb: 5\nc: 3.2\ne: true\n",
 		},
@@ -86,9 +87,10 @@ e: >-
 		},
 	},
 	{
-		description: "Read style",
-		document:    `{a: "cat", b: 'thing'}`,
-		expression:  `.. | style`,
+		description:           "Read style",
+		document:              `{a: "cat", b: 'thing'}`,
+		dontFormatInputForDoc: true,
+		expression:            `.. | style`,
 		expected: []string{
 			"D0, P[], (!!str)::flow\n",
 			"D0, P[a], (!!str)::double\n",
@@ -110,5 +112,5 @@ func TestStyleOperatorScenarios(t *testing.T) {
 	for _, tt := range styleOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Style Operator", styleOperatorScenarios)
+	documentScenarios(t, "Style", styleOperatorScenarios)
 }

pkg/yqlib/operator_tag_test.go

@@ -32,5 +32,5 @@ func TestTagOperatorScenarios(t *testing.T) {
 	for _, tt := range tagOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Tag Operator", tagOperatorScenarios)
+	documentScenarios(t, "Tag", tagOperatorScenarios)
 }

pkg/yqlib/operator_traverse_path_test.go

@@ -45,6 +45,15 @@ var traversePathOperatorScenarios = []expressionScenario{
 			"D0, P[1], (!!map)::{c: banana}\n",
 		},
 	},
+	{
+		description:    "Special characters",
+		subdescription: "Use quotes around path elements with special characters",
+		document:       `{"{}": frog}`,
+		expression:     `."{}"`,
+		expected: []string{
+			"D0, P[{}], (!!str)::frog\n",
+		},
+	},
 	{
 		description:    "Children don't exist",
 		subdescription: "Nodes are added dynamically while traversing",
@@ -150,7 +159,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Traversing arrays by index",
 		document:    `[1,2,3]`,
-		expression:  `[0]`,
+		expression:  `.[0]`,
 		expected: []string{
 			"D0, P[0], (!!int)::1\n",
 		},
@@ -158,7 +167,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Maps with numeric keys",
 		document:    `{2: cat}`,
-		expression:  `[2]`,
+		expression:  `.[2]`,
 		expected: []string{
 			"D0, P[2], (!!str)::cat\n",
 		},
@@ -166,7 +175,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Maps with non existing numeric keys",
 		document:    `{a: b}`,
-		expression:  `[0]`,
+		expression:  `.[0]`,
 		expected: []string{
 			"D0, P[0], (!!null)::null\n",
 		},
@@ -271,5 +280,5 @@ func TestTraversePathOperatorScenarios(t *testing.T) {
 	for _, tt := range traversePathOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Traverse Operator", traversePathOperatorScenarios)
+	documentScenarios(t, "Traverse", traversePathOperatorScenarios)
 }

pkg/yqlib/operator_union_test.go

@@ -29,5 +29,5 @@ func TestUnionOperatorScenarios(t *testing.T) {
 	for _, tt := range unionOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Union Operator", unionOperatorScenarios)
+	documentScenarios(t, "Union", unionOperatorScenarios)
 }

pkg/yqlib/operators_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"github.com/mikefarah/yq/v4/test"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type expressionScenario struct {
@@ -29,17 +30,26 @@ func testScenario(t *testing.T, s *expressionScenario) {
 
 	node, err := treeCreator.ParsePath(s.expression)
 	if err != nil {
-		t.Error(err)
+		t.Error(fmt.Errorf("Error parsing expression %v of %v: %v", s.expression, s.description, err))
 		return
 	}
 	inputs := list.New()
 
 	if s.document != "" {
-		inputs, err = readDocuments(strings.NewReader(s.document), "sample.yml")
+		inputs, err = readDocuments(strings.NewReader(s.document), "sample.yml", 0)
 		if err != nil {
-			t.Error(err)
+			t.Error(err, s.document)
 			return
 		}
+	} else {
+		candidateNode := &CandidateNode{
+			Document:  0,
+			Filename:  "",
+			Node:      &yaml.Node{Tag: "!!null"},
+			FileIndex: 0,
+		}
+		inputs.PushBack(candidateNode)
+
 	}
 
 	results, err = treeNavigator.GetMatchingNodes(inputs, node)
@@ -90,7 +100,8 @@ func formatYaml(yaml string) string {
 	if err != nil {
 		panic(err)
 	}
-	err = EvaluateStream("sample.yaml", strings.NewReader(yaml), node, printer)
+	streamEvaluator := NewStreamEvaluator()
+	err = streamEvaluator.Evaluate("sample.yaml", strings.NewReader(yaml), node, printer)
 	if err != nil {
 		panic(err)
 	}
@@ -113,17 +124,13 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 	}
 
 	w := bufio.NewWriter(f)
+	writeOrPanic(w, "\n")
 
-	writeOrPanic(w, "\n## Examples\n")
-
-	for index, s := range scenarios {
+	for _, s := range scenarios {
 		if !s.skipDoc {
 
-			if s.description != "" {
-				writeOrPanic(w, fmt.Sprintf("### %v\n", s.description))
-			} else {
-				writeOrPanic(w, fmt.Sprintf("### Example %v\n", index))
-			}
+			writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
+
 			if s.subdescription != "" {
 				writeOrPanic(w, s.subdescription)
 				writeOrPanic(w, "\n\n")
@@ -131,7 +138,7 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 			formattedDoc := ""
 			if s.document != "" {
 				if s.dontFormatInputForDoc {
-					formattedDoc = s.document
+					formattedDoc = s.document + "\n"
 				} else {
 					formattedDoc = formatYaml(s.document)
 				}
@@ -155,18 +162,20 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 			var output bytes.Buffer
 			var err error
 			printer := NewPrinter(bufio.NewWriter(&output), false, true, false, 2, true)
+			streamEvaluator := NewStreamEvaluator()
 
 			if s.document != "" {
 				node, err := treeCreator.ParsePath(s.expression)
 				if err != nil {
 					t.Error(err)
 				}
-				err = EvaluateStream("sample.yaml", strings.NewReader(formattedDoc), node, printer)
+				err = streamEvaluator.Evaluate("sample.yaml", strings.NewReader(formattedDoc), node, printer)
+
 				if err != nil {
 					t.Error(err)
 				}
 			} else {
-				err = EvaluateAllFileStreams(s.expression, []string{}, printer)
+				err = streamEvaluator.EvaluateNew(s.expression, printer)
 				if err != nil {
 					t.Error(err)
 				}

pkg/yqlib/path_parse_test.go

@@ -37,8 +37,23 @@ var pathTests = []struct {
 	// {`.a, .b`, append(make([]interface{}, 0), "a", "OR", "b")},
 	// {`[.a, .b]`, append(make([]interface{}, 0), "[", "a", "OR", "b", "]")},
 	// {`."[a", ."b]"`, append(make([]interface{}, 0), "[a", "OR", "b]")},
-	// {`.a[]`, append(make([]interface{}, 0), "a", "PIPE", "[]")},
+	// {`.a.[]`, append(make([]interface{}, 0), "a", "PIPE", "[]")},
 	// {`.[].a`, append(make([]interface{}, 0), "[]", "PIPE", "a")},
+	// {
+	// 	`["cat"]`,
+	// 	append(make([]interface{}, 0), "[", "cat (string)", "]"),
+	// 	append(make([]interface{}, 0), "cat (string)", "COLLECT", "PIPE"),
+	// },
+	{
+		`[]`,
+		append(make([]interface{}, 0), "[", "]"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "PIPE"),
+	},
+	{
+		`[3]`,
+		append(make([]interface{}, 0), "[", "3 (int64)", "]"),
+		append(make([]interface{}, 0), "3 (int64)", "COLLECT", "PIPE"),
+	},
 	{
 		`d0.a`,
 		append(make([]interface{}, 0), "d0", "PIPE", "a"),
@@ -85,7 +100,7 @@ var pathTests = []struct {
 		append(make([]interface{}, 0), "a", "mike (string)", "CREATE_MAP", "COLLECT_OBJECT", "PIPE"),
 	},
 	{
-		`{.a: .c, .b[]: .f.g[]}`,
+		`{.a: .c, .b.[]: .f.g.[]}`,
 		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "PIPE", "[]", "CREATE_MAP", "f", "PIPE", "g", "PIPE", "[]", "}"),
 		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "[]", "PIPE", "f", "g", "PIPE", "[]", "PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "PIPE"),
 	},