Can assign-update tag

.github/ISSUE_TEMPLATE/bug_report_v3.md

@@ -10,6 +10,8 @@ assignees: ''
 **Describe the bug**
 A clear and concise description of what the bug is.
 
+Note that any how to questions should be posted in the discussion board and not raised as an issue.
+
 Version of yq: 3.X.X
 Operating system: mac/linux/windows/....
 Installed via: docker/binary release/homebrew/snap/...

.github/ISSUE_TEMPLATE/bug_report_v4.md

@@ -10,6 +10,8 @@ assignees: ''
 **Describe the bug**
 A clear and concise description of what the bug is.
 
+Note that any how to questions should be posted in the discussion board and not raised as an issue.
+
 Version of yq: 4.X.X
 Operating system: mac/linux/windows/....
 Installed via: docker/binary release/homebrew/snap/...

.github/ISSUE_TEMPLATE/feature_request.md

@@ -9,9 +9,11 @@ assignees: ''
 
 **Please describe your feature request.**
 A clear and concise description of what the request is and what it would solve. 
-Ex. I wish I could use yq to [...]
+Eg. I wish I could use yq to [...]
 
-Please note that V3 will no longer have any enhancements.
+Note:
+- how to questions should be posted in the discussion board and not raised as an issue.
+- V3 will no longer have any enhancements.
 
 **Describe the solution you'd like**
 If we have data1.yml like:

.github/workflows/release.yml

@@ -68,7 +68,9 @@ jobs:
  
       - name: Build and push image
         run: |
-          IMAGE_VERSION="$(git describe --tags --abbrev=0)"
+          IMAGE_V_VERSION="$(git describe --tags --abbrev=0)"
+          IMAGE_VERSION=${IMAGE_V_VERSION:1}
+
           SHORT_SHA1=$(git rev-parse --short HEAD)
           PLATFORMS="linux/amd64,linux/ppc64le,linux/arm64"
           echo "Building and pushing version ${IMAGE_VERSION} of image ${IMAGE_NAME}"

Dockerfile.dev

@@ -4,6 +4,7 @@ COPY scripts/devtools.sh /opt/devtools.sh
 
 RUN set -e -x \
     && /opt/devtools.sh
+ENV PATH=/go/bin:$PATH
 
 # install mkdocs
 RUN set -ex \

README.md

@@ -3,30 +3,64 @@
 ![Build](https://github.com/mikefarah/yq/workflows/Build/badge.svg)  ![Docker Pulls](https://img.shields.io/docker/pulls/mikefarah/yq.svg) ![Github Releases (by Release)](https://img.shields.io/github/downloads/mikefarah/yq/total.svg) ![Go Report](https://goreportcard.com/badge/github.com/mikefarah/yq)
 
 
-a lightweight and portable command-line YAML processor
+a lightweight and portable command-line YAML processor. `yq` uses [jq](https://github.com/stedolan/jq) like syntax but works with yaml files as well as json. It doesn't yet support everything `jq` does - but it does support the most common operations and functions, and more is being added continuously.
 
-The aim of the project is to be the [jq](https://github.com/stedolan/jq) or sed of yaml files.
+yq is written in go - so you can download a dependency free binary for your platform and you are good to go! If you prefer there are a variety of package managers that can be used as well as docker, all listed below.
 
 ## V4 released!
 V4 is now officially released, it's quite different from V3 (sorry for the migration), however it is much more similar to ```jq```, using a similar expression syntax and therefore support much more complex functionality! 
 
 If you've been using v3 and want/need to upgrade, checkout the [upgrade guide](https://mikefarah.gitbook.io/yq/v/v4.x/upgrading-from-v3).
 
+Support for v3 will cease August 2021, until then, critical bug and security fixes will still get applied if required.
+
 ## Install
 
 ### [Download the latest binary](https://github.com/mikefarah/yq/releases/latest)
 
-### MacOS:
+### wget
+Use wget to download the pre-compiled binaries:
+
+#### Compressed via tar.gz
+```bash
+wget https://github.com/mikefarah/yq/releases/download/${VERSION}/${BINARY}.tar.gz -O - |\
+  tar xz && mv ${BINARY} /usr/bin/yq
+```
+
+#### Plain binary
+
+```bash
+wget https://github.com/mikefarah/yq/releases/download/${VERSION}/${BINARY} -O /usr/bin/yq &&\
+    chmod +x /usr/bin/yq
+```
+
+For instance, VERSION=v4.2.0 and BINARY=yq_linux_amd64
+
+### MacOS / Linux via Homebrew:
 Using [Homebrew](https://brew.sh/)
 ```
 brew install yq
 ```
 
-### Ubuntu and other Linux distros supporting `snap` packages:
+or, for the (deprecated) v3 version:
+
+```
+brew install yq@3
+```
+
+Note that for v3, as it is a versioned brew it will not add the `yq` command to your path automatically. Please follow the instructions given by brew upon installation.
+
+### Linux via snap:
 ```
 snap install yq
 ```
 
+or, for the (deprecated) v3 version:
+
+```
+snap install yq --channel=v3/stable
+```
+
 #### Snap notes
 `yq` installs with [_strict confinement_](https://docs.snapcraft.io/snap-confinement/6233) in snap, this means it doesn't have direct access to root files. To read root files you can:
 
@@ -45,17 +79,6 @@ sudo mv /etc/myfile.tmp /etc/myfile
 rm /etc/myfile.tmp
 ```
 
-### wget
-
-Use wget to download the pre-compiled binaries:
-
-```bash
-wget https://github.com/mikefarah/yq/releases/download/${VERSION}/${BINARY} -O /usr/bin/yq &&\
-    chmod +x /usr/bin/yq
-```
-
-For instance, VERSION=4.0.0 and BINARY=yq_linux_amd64
-
 ### Run with Docker
 
 #### Oneshot use:
@@ -80,7 +103,7 @@ yq() {
 
 ### Go Get:
 ```
-GO111MODULE=on go get github.com/mikefarah/yq/v4
+GO111MODULE=on go get github.com/mikefarah/yq
 ```
 
 ## Community Supported Installation methods
@@ -126,7 +149,7 @@ Supported by @rmescandon (https://launchpad.net/~rmescandon/+archive/ubuntu/yq)
 - Colorized yaml output
 - [Deeply traverse yaml](https://mikefarah.gitbook.io/yq/v/v4.x/traverse)
 - [Sort yaml by keys](https://mikefarah.gitbook.io/yq/v/v4.x/sort-keys)
-- Manipulate yaml [comments](https://app.gitbook.com/@mikefarah/s/yq/v/v4.x/comment-operators), [styling](https://app.gitbook.com/@mikefarah/s/yq/v/v4.x/style), [tags](https://app.gitbook.com/@mikefarah/s/yq/v/v4.x/tag) and [anchors](https://app.gitbook.com/@mikefarah/s/yq/v/v4.x/explode).
+- Manipulate yaml [comments](https://mikefarah.gitbook.io/yq/comment-operators), [styling](https://mikefarah.gitbook.io/yq/style), [tags](https://mikefarah.gitbook.io/yq/tag) and [anchors and aliases](https://mikefarah.gitbook.io/yq/anchor-and-alias-operators).
 - [Update yaml inplace](https://mikefarah.gitbook.io/yq/v/v4.x/commands/evaluate#flags)
 - [Complex expressions to select and update](https://mikefarah.gitbook.io/yq/v/v4.x/select#select-and-update-matching-values-in-map)
 - Keeps yaml formatting and comments when updating (though there are issues with whitespace)
@@ -158,6 +181,7 @@ Flags:
   -M, --no-colors     force print with no colors
   -N, --no-doc        Don't print document separators (---)
   -n, --null-input    Don't read input, simply evaluate the expression given. Useful for creating yaml docs from scratch.
+  -P, --prettyPrint    pretty print, shorthand for '... style = ""' 
   -j, --tojson        output as json. Set indent to 0 to print json in one line.
   -v, --verbose       verbose mode
   -V, --version       Print version information and quit

cmd/constant.go

@@ -14,5 +14,6 @@ var noDocSeparators = false
 var nullInput = false
 var verbose = false
 var version = false
+var prettyPrint = false
 
 var completedSuccessfully = false

cmd/evaluate_all_command.go

@@ -65,19 +65,19 @@ func evaluateAll(cmd *cobra.Command, args []string) error {
 	switch len(args) {
 	case 0:
 		if pipingStdIn {
-			err = allAtOnceEvaluator.EvaluateFiles("", []string{"-"}, printer)
+			err = allAtOnceEvaluator.EvaluateFiles(processExpression(""), []string{"-"}, printer)
 		} else {
 			cmd.Println(cmd.UsageString())
 			return nil
 		}
 	case 1:
 		if nullInput {
-			err = yqlib.NewStreamEvaluator().EvaluateNew(args[0], printer)
+			err = yqlib.NewStreamEvaluator().EvaluateNew(processExpression(args[0]), printer)
 		} else {
-			err = allAtOnceEvaluator.EvaluateFiles("", []string{args[0]}, printer)
+			err = allAtOnceEvaluator.EvaluateFiles(processExpression(""), []string{args[0]}, printer)
 		}
 	default:
-		err = allAtOnceEvaluator.EvaluateFiles(args[0], args[1:], printer)
+		err = allAtOnceEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer)
 	}
 
 	completedSuccessfully = err == nil

cmd/evalute_sequence_command.go

@@ -33,6 +33,16 @@ yq e '.a.b = "cool"' -i file.yaml
 	}
 	return cmdEvalSequence
 }
+
+func processExpression(expression string) string {
+	if prettyPrint && expression == "" {
+		return `... style=""`
+	} else if prettyPrint {
+		return fmt.Sprintf("%v | ... style= \"\"", expression)
+	}
+	return expression
+}
+
 func evaluateSequence(cmd *cobra.Command, args []string) error {
 	cmd.SilenceUsage = true
 	// 0 args, read std in
@@ -76,16 +86,16 @@ func evaluateSequence(cmd *cobra.Command, args []string) error {
 	switch len(args) {
 	case 0:
 		if pipingStdIn {
-			err = streamEvaluator.EvaluateFiles("", []string{"-"}, printer)
+			err = streamEvaluator.EvaluateFiles(processExpression(""), []string{"-"}, printer)
 		} else {
 			cmd.Println(cmd.UsageString())
 			return nil
 		}
 	case 1:
 		if nullInput {
-			err = streamEvaluator.EvaluateNew(args[0], printer)
+			err = streamEvaluator.EvaluateNew(processExpression(args[0]), printer)
 		} else {
-			err = streamEvaluator.EvaluateFiles("", []string{args[0]}, printer)
+			err = streamEvaluator.EvaluateFiles(processExpression(""), []string{args[0]}, printer)
 		}
 	default:
 		err = streamEvaluator.EvaluateFiles(args[0], args[1:], printer)

cmd/root.go

@@ -48,6 +48,7 @@ func New() *cobra.Command {
 	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(&unwrapScalar, "unwrapScalar", "", true, "unwrap scalar, print the value with no quotes, colors or comments")
+	rootCmd.PersistentFlags().BoolVarP(&prettyPrint, "prettyPrint", "P", false, "pretty print, shorthand for '... style = \"\"'")
 	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")

cmd/version.go

@@ -11,7 +11,7 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "4.1.0"
+	Version = "4.2.1"
 
 	// 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

github-action/Dockerfile

@@ -1,4 +1,4 @@
-FROM mikefarah/yq:3
+FROM mikefarah/yq:4.2.1
 
 COPY entrypoint.sh /entrypoint.sh
 

pkg/yqlib/candidate_node.go

@@ -21,6 +21,14 @@ func (n *CandidateNode) GetKey() string {
 	return fmt.Sprintf("%v - %v", n.Document, n.Path)
 }
 
+func (n *CandidateNode) CreateChildPath(path interface{}) []interface{} {
+	//don't use append as they may actually modify the path of the orignal node!
+	newPath := make([]interface{}, len(n.Path)+1)
+	copy(newPath, n.Path)
+	newPath[len(n.Path)] = path
+	return newPath
+}
+
 func (n *CandidateNode) Copy() (*CandidateNode, error) {
 	clone := &CandidateNode{}
 	err := copier.Copy(clone, n)
@@ -32,6 +40,7 @@ func (n *CandidateNode) Copy() (*CandidateNode, error) {
 
 // updates this candidate from the given candidate node
 func (n *CandidateNode) UpdateFrom(other *CandidateNode) {
+
 	n.UpdateAttributesFrom(other)
 	n.Node.Content = other.Node.Content
 	n.Node.Value = other.Node.Value

pkg/yqlib/doc/Anchor and Alias Operators.md

@@ -31,6 +31,22 @@ will output
 a: &foobar cat
 ```
 
+## Set anchor relatively using assign-update
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a anchor |= .b' sample.yml
+```
+will output
+```yaml
+a: &cat
+  b: cat
+```
+
 ## Get alias
 Given a sample.yml file of:
 ```yaml
@@ -62,6 +78,23 @@ b: &meow purr
 a: *meow
 ```
 
+## Set alias relatively using assign-update
+Given a sample.yml file of:
+```yaml
+b: &meow purr
+a:
+  f: meow
+```
+then
+```bash
+yq eval '.a alias |= .f' sample.yml
+```
+will output
+```yaml
+b: &meow purr
+a: *meow
+```
+
 ## Explode alias and anchor
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Assign.md

@@ -34,6 +34,27 @@ a:
   g: foof
 ```
 
+## Update node from another file
+Note this will also work when the second file is a scalar (string/number)
+
+Given a sample.yml file of:
+```yaml
+a: apples
+```
+And another sample another.yml file of:
+```yaml
+b: bob
+```
+then
+```bash
+yq eval-all 'select(fileIndex==0).a = select(fileIndex==1) | select(fileIndex==0)' sample.yml another.yml
+```
+will output
+```yaml
+a:
+  b: bob
+```
+
 ## Update node to be the sibling value
 Given a sample.yml file of:
 ```yaml
@@ -112,7 +133,7 @@ a:
 ```
 then
 ```bash
-yq eval '(.a.[] | select(. == "apple")) = "frog"' sample.yml
+yq eval '(.a[] | select(. == "apple")) = "frog"' sample.yml
 ```
 will output
 ```yaml

pkg/yqlib/doc/Comment Operators.md

@@ -13,6 +13,22 @@ will output
 a: cat # single
 ```
 
+## Use update assign to perform relative updates
+Given a sample.yml file of:
+```yaml
+a: cat
+b: dog
+```
+then
+```bash
+yq eval '.. lineComment |= .' sample.yml
+```
+will output
+```yaml
+a: cat # cat
+b: dog # dog
+```
+
 ## Set head comment
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Document Index.md

@@ -17,6 +17,24 @@ will output
 1
 ```
 
+## Retrieve a document index, shorthand
+Given a sample.yml file of:
+```yaml
+a: cat
+---
+a: frog
+```
+then
+```bash
+yq eval '.a | di' sample.yml
+```
+will output
+```yaml
+0
+---
+1
+```
+
 ## Filter by document index
 Given a sample.yml file of:
 ```yaml
@@ -26,7 +44,23 @@ a: frog
 ```
 then
 ```bash
-yq eval 'select(. | documentIndex == 1)' sample.yml
+yq eval 'select(documentIndex == 1)' sample.yml
+```
+will output
+```yaml
+a: frog
+```
+
+## Filter by document index shorthand
+Given a sample.yml file of:
+```yaml
+a: cat
+---
+a: frog
+```
+then
+```bash
+yq eval 'select(di == 1)' sample.yml
 ```
 will output
 ```yaml
@@ -42,7 +76,7 @@ a: frog
 ```
 then
 ```bash
-yq eval '.a | ({"match": ., "doc": (. | documentIndex)})' sample.yml
+yq eval '.a | ({"match": ., "doc": documentIndex})' sample.yml
 ```
 will output
 ```yaml

pkg/yqlib/doc/File Operators.md

@@ -1,9 +1,11 @@
 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).
 
+Note that the `fileIndex` operator has a short alias of `fi`.
+
 ## 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
+yq eval-all 'select(fi == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
 ```
 ## Get filename
 Given a sample.yml file of:
@@ -16,7 +18,7 @@ yq eval 'filename' sample.yml
 ```
 will output
 ```yaml
-sample.yaml
+sample.yml
 ```
 
 ## Get file index
@@ -33,3 +35,17 @@ will output
 0
 ```
 
+## Get file index alias
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval 'fi' sample.yml
+```
+will output
+```yaml
+0
+```
+

pkg/yqlib/doc/Recursive Descent.md

@@ -1,8 +1,55 @@
-This operator recursively matches all children nodes given of a particular element, including that node itself. This is most often used to apply a filter recursively against all matches, for instance to set the `style` of all nodes in a yaml doc:
+This operator recursively matches all children nodes given of a particular element, including that node itself. This is most often used to apply a filter recursively against all matches. It can be used in either the 
+
+## match values form `..`
+This will, like the `jq` equivalent, recursively match all _value_ nodes. Use it to find/manipulate particular values.
+
+For instance to set the `style` of all _value_ nodes in a yaml doc, excluding map keys:
 
 ```bash
 yq eval '.. style= "flow"' file.yaml
 ```
+
+## match values and map keys form `...`
+The also includes map keys in the results set. This is particularly useful in YAML as unlike JSON, map keys can have their own styling, tags and use anchors and aliases.
+
+For instance to set the `style` of all nodes in a yaml doc, including the map keys:
+
+```bash
+yq eval '... style= "flow"' file.yaml
+```
+## Recurse map (values only)
+Given a sample.yml file of:
+```yaml
+a: frog
+```
+then
+```bash
+yq eval '..' sample.yml
+```
+will output
+```yaml
+a: frog
+frog
+```
+
+## Recurse map (values and keys)
+Note that the map key appears in the results
+
+Given a sample.yml file of:
+```yaml
+a: frog
+```
+then
+```bash
+yq eval '...' sample.yml
+```
+will output
+```yaml
+a: frog
+a
+frog
+```
+
 ## Aliases are not traversed
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Style.md

@@ -40,6 +40,26 @@ c: "3.2"
 e: "true"
 ```
 
+## Set double quote style on map keys too
+Given a sample.yml file of:
+```yaml
+a: cat
+b: 5
+c: 3.2
+e: true
+```
+then
+```bash
+yq eval '... style="double"' sample.yml
+```
+will output
+```yaml
+"a": "cat"
+"b": "5"
+"c": "3.2"
+"e": "true"
+```
+
 ## Set single quote style
 Given a sample.yml file of:
 ```yaml
@@ -125,19 +145,19 @@ will output
 {a: cat, b: 5, c: 3.2, e: true}
 ```
 
-## Pretty print
-Set empty (default) quote style
+## Reset style - or pretty print
+Set empty (default) quote style, note the usage of `...` to match keys too. Note that there is a `--prettyPrint/-P` short flag for this.
 
 Given a sample.yml file of:
 ```yaml
 a: cat
-b: 5
-c: 3.2
-e: true
+"b": 5
+'c': 3.2
+"e": true
 ```
 then
 ```bash
-yq eval '.. style=""' sample.yml
+yq eval '... style=""' sample.yml
 ```
 will output
 ```yaml
@@ -147,6 +167,22 @@ c: 3.2
 e: true
 ```
 
+## Set style relatively with assign-update
+Given a sample.yml file of:
+```yaml
+a: single
+b: double
+```
+then
+```bash
+yq eval '.[] style |= .' sample.yml
+```
+will output
+```yaml
+a: 'single'
+b: "double"
+```
+
 ## Read style
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Tag.md

@@ -22,7 +22,21 @@ will output
 !!seq
 ```
 
-## Convert numbers to strings
+## Set custom tag
+Given a sample.yml file of:
+```yaml
+a: str
+```
+then
+```bash
+yq eval '.a tag = "!!mikefarah"' sample.yml
+```
+will output
+```yaml
+a: !!mikefarah str
+```
+
+## Find numbers and convert them to strings
 Given a sample.yml file of:
 ```yaml
 a: cat

pkg/yqlib/doc/Traverse.md

@@ -106,7 +106,7 @@ b: *cat
 ```
 then
 ```bash
-yq eval '.b.[]' sample.yml
+yq eval '.b[]' sample.yml
 ```
 will output
 ```yaml
@@ -290,7 +290,7 @@ foobar:
 ```
 then
 ```bash
-yq eval '.foobar.[]' sample.yml
+yq eval '.foobar[]' sample.yml
 ```
 will output
 ```yaml
@@ -356,7 +356,7 @@ foobar:
 ```
 then
 ```bash
-yq eval '.foobarList.[]' sample.yml
+yq eval '.foobarList[]' sample.yml
 ```
 will output
 ```yaml
@@ -366,3 +366,21 @@ bar_thing
 foobarList_c
 ```
 
+## Select multiple indices
+Given a sample.yml file of:
+```yaml
+a:
+  - a
+  - b
+  - c
+```
+then
+```bash
+yq eval '.a[0, 2]' sample.yml
+```
+will output
+```yaml
+a
+c
+```
+

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

@@ -1,7 +1,9 @@
 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).
 
+Note that the `fileIndex` operator has a short alias of `fi`.
+
 ## 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
+yq eval-all 'select(fi == 0) * select(filename == "file2.yaml")' file1.yaml file2.yaml
 ```

pkg/yqlib/doc/headers/Recursive Descent.md

@@ -1,5 +1,19 @@
-This operator recursively matches all children nodes given of a particular element, including that node itself. This is most often used to apply a filter recursively against all matches, for instance to set the `style` of all nodes in a yaml doc:
+This operator recursively matches all children nodes given of a particular element, including that node itself. This is most often used to apply a filter recursively against all matches. It can be used in either the 
+
+## match values form `..`
+This will, like the `jq` equivalent, recursively match all _value_ nodes. Use it to find/manipulate particular values.
+
+For instance to set the `style` of all _value_ nodes in a yaml doc, excluding map keys:
 
 ```bash
 yq eval '.. style= "flow"' file.yaml
 ```
+
+## match values and map keys form `...`
+The also includes map keys in the results set. This is particularly useful in YAML as unlike JSON, map keys can have their own styling, tags and use anchors and aliases.
+
+For instance to set the `style` of all nodes in a yaml doc, including the map keys:
+
+```bash
+yq eval '... style= "flow"' file.yaml
+```

pkg/yqlib/lib.go

@@ -19,7 +19,7 @@ type OperationType struct {
 }
 
 // operators TODO:
-// - cookbook doc for common things
+// - keys operator for controlling key metadata (particularly anchors/aliases)
 // - mergeEmpty (sets only if the document is empty, do I do that now?)
 
 var Or = &OperationType{Type: "OR", NumArgs: 2, Precedence: 20, Handler: OrOperator}
@@ -65,6 +65,7 @@ var SortKeys = &OperationType{Type: "SORT_KEYS", NumArgs: 1, Precedence: 50, Han
 
 var CollectObject = &OperationType{Type: "COLLECT_OBJECT", NumArgs: 0, Precedence: 50, Handler: CollectObjectOperator}
 var TraversePath = &OperationType{Type: "TRAVERSE_PATH", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
+var TraverseArray = &OperationType{Type: "TRAVERSE_ARRAY", NumArgs: 1, Precedence: 50, Handler: TraverseArrayOperator}
 
 var DocumentFilter = &OperationType{Type: "DOCUMENT_FILTER", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
 var SelfReference = &OperationType{Type: "SELF", NumArgs: 0, Precedence: 50, Handler: SelfOperator}
@@ -85,6 +86,7 @@ type Operation struct {
 	StringValue   string
 	CandidateNode *CandidateNode // used for Value Path elements
 	Preferences   interface{}
+	UpdateAssign  bool // used for assign ops, when true it means we evaluate the rhs given the lhs (instead of matching nodes)
 }
 
 func CreateValueOperation(value interface{}, stringValue string) *Operation {

pkg/yqlib/operator_add.go

@@ -16,7 +16,7 @@ func createSelfAddOp(rhs *PathTreeNode) *PathTreeNode {
 
 func AddAssignOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	assignmentOp := &Operation{OperationType: Assign}
-	assignmentOp.Preferences = &AssignOpPreferences{true}
+	assignmentOp.UpdateAssign = true
 
 	assignmentOpNode := &PathTreeNode{Operation: assignmentOp, Lhs: pathNode.Lhs, Rhs: createSelfAddOp(pathNode.Rhs)}
 	return d.GetMatchingNodes(matchingNodes, assignmentOpNode)

pkg/yqlib/operator_anchors_aliases.go

@@ -3,21 +3,23 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func AssignAliasOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 
 	log.Debugf("AssignAlias operator!")
 
+	aliasName := ""
+	if !pathNode.Operation.UpdateAssign {
 		rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 		if err != nil {
 			return nil, err
 		}
-	aliasName := ""
 		if rhs.Front() != nil {
 			aliasName = rhs.Front().Value.(*CandidateNode).Node.Value
 		}
+	}
 
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 
@@ -28,6 +30,17 @@ func AssignAliasOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNod
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		log.Debugf("Setting aliasName : %v", candidate.GetKey())
+
+		if pathNode.Operation.UpdateAssign {
+			rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+			if err != nil {
+				return nil, err
+			}
+			if rhs.Front() != nil {
+				aliasName = rhs.Front().Value.(*CandidateNode).Node.Value
+			}
+		}
+
 		candidate.Node.Kind = yaml.AliasNode
 		candidate.Node.Value = aliasName
 	}
@@ -51,14 +64,17 @@ func AssignAnchorOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNo
 
 	log.Debugf("AssignAnchor operator!")
 
+	anchorName := ""
+	if !pathNode.Operation.UpdateAssign {
 		rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 		if err != nil {
 			return nil, err
 		}
-	anchorName := ""
+
 		if rhs.Front() != nil {
 			anchorName = rhs.Front().Value.(*CandidateNode).Node.Value
 		}
+	}
 
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 
@@ -69,6 +85,18 @@ func AssignAnchorOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNo
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		log.Debugf("Setting anchorName of : %v", candidate.GetKey())
+
+		if pathNode.Operation.UpdateAssign {
+			rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+			if err != nil {
+				return nil, err
+			}
+
+			if rhs.Front() != nil {
+				anchorName = rhs.Front().Value.(*CandidateNode).Node.Value
+			}
+		}
+
 		candidate.Node.Anchor = anchorName
 	}
 	return matchingNodes, nil

pkg/yqlib/operator_anchors_aliases_test.go

@@ -21,6 +21,14 @@ var anchorOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::a: &foobar cat\n",
 		},
 	},
+	{
+		description: "Set anchor relatively using assign-update",
+		document:    `a: {b: cat}`,
+		expression:  `.a anchor |= .b`,
+		expected: []string{
+			"D0, P[], (doc)::a: &cat {b: cat}\n",
+		},
+	},
 	{
 		description: "Get alias",
 		document:    `{b: &billyBob meow, a: *billyBob}`,
@@ -37,6 +45,14 @@ var anchorOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
 		},
 	},
+	{
+		description: "Set alias relatively using assign-update",
+		document:    `{b: &meow purr, a: {f: meow}}`,
+		expression:  `.a alias |= .f`,
+		expected: []string{
+			"D0, P[], (doc)::{b: &meow purr, a: *meow}\n",
+		},
+	},
 	{
 		description: "Explode alias and anchor",
 		document:    `{f : {a: &a cat, b: *a}}`,
@@ -118,5 +134,5 @@ func TestAnchorAliaseOperatorScenarios(t *testing.T) {
 	for _, tt := range anchorOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Anchor and Aliases Operators", anchorOperatorScenarios)
+	documentScenarios(t, "Anchor and Alias Operators", anchorOperatorScenarios)
 }

pkg/yqlib/operator_assign.go

@@ -2,26 +2,20 @@ package yqlib
 
 import "container/list"
 
-type AssignOpPreferences struct {
-	UpdateAssign bool
-}
-
 func AssignUpdateOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 	if err != nil {
 		return nil, err
 	}
-	preferences := pathNode.Operation.Preferences.(*AssignOpPreferences)
-
 	var rhs *list.List
-	if !preferences.UpdateAssign {
+	if !pathNode.Operation.UpdateAssign {
 		rhs, err = d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 	}
 
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 
-		if preferences.UpdateAssign {
+		if pathNode.Operation.UpdateAssign {
 			rhs, err = d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
 		}
 
@@ -33,7 +27,9 @@ func AssignUpdateOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNo
 		first := rhs.Front()
 
 		if first != nil {
-			candidate.UpdateFrom(first.Value.(*CandidateNode))
+			rhsCandidate := first.Value.(*CandidateNode)
+			rhsCandidate.Node = UnwrapDoc(rhsCandidate.Node)
+			candidate.UpdateFrom(rhsCandidate)
 		}
 	}
 	// // if there was nothing given, perhaps we are creating a new yaml doc

pkg/yqlib/operator_assign_test.go

@@ -20,6 +20,16 @@ var assignOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::{a: {g: foof}}\n",
 		},
 	},
+	{
+		description:    "Update node from another file",
+		subdescription: "Note this will also work when the second file is a scalar (string/number)",
+		document:       `{a: apples}`,
+		document2:      "{b: bob}",
+		expression:     `select(fileIndex==0).a = select(fileIndex==1) | select(fileIndex==0)`,
+		expected: []string{
+			"D0, P[], (doc)::{a: {b: bob}}\n",
+		},
+	},
 	{
 		description: "Update node to be the sibling value",
 		document:    `{a: {b: child}, b: sibling}`,
@@ -80,6 +90,14 @@ var assignOperatorScenarios = []expressionScenario{
 	{
 		description: "Update selected results",
 		document:    `{a: {b: apple, c: cactus}}`,
+		expression:  `(.a[] | select(. == "apple")) = "frog"`,
+		expected: []string{
+			"D0, P[], (doc)::{a: {b: frog, c: cactus}}\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: {b: apple, c: cactus}}`,
 		expression: `(.a.[] | select(. == "apple")) = "frog"`,
 		expected: []string{
 			"D0, P[], (doc)::{a: {b: frog, c: cactus}}\n",

pkg/yqlib/operator_collect_object.go

@@ -55,7 +55,7 @@ func CollectObjectOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *
 func createChildCandidate(candidate *CandidateNode, index int) *CandidateNode {
 	return &CandidateNode{
 		Document: candidate.Document,
-		Path:     append(candidate.Path, index),
+		Path:     candidate.CreateChildPath(index),
 		Filename: candidate.Filename,
 		Node:     candidate.Node.Content[index],
 	}
@@ -67,7 +67,9 @@ func collect(d *dataTreeNavigator, aggregate *list.List, remainingMatches *list.
 	}
 
 	candidate := remainingMatches.Remove(remainingMatches.Front()).(*CandidateNode)
-	splatted, err := Splat(d, nodeToMap(candidate))
+
+	splatted, err := Splat(d, nodeToMap(candidate),
+		&TraversePreferences{FollowAlias: false, IncludeMapKeys: false})
 
 	for splatEl := splatted.Front(); splatEl != nil; splatEl = splatEl.Next() {
 		splatEl.Value.(*CandidateNode).Path = nil

pkg/yqlib/operator_collect_object_test.go

@@ -110,5 +110,5 @@ func TestCollectObjectOperatorScenarios(t *testing.T) {
 	for _, tt := range collectObjectOperatorScenarios {
 		testScenario(t, &tt)
 	}
-	documentScenarios(t, "Collect into Object", collectObjectOperatorScenarios)
+	documentScenarios(t, "Create, Collect into Object", collectObjectOperatorScenarios)
 }

pkg/yqlib/operator_comments.go

@@ -4,7 +4,7 @@ import (
 	"container/list"
 	"strings"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type CommentOpPreferences struct {
@@ -17,15 +17,6 @@ func AssignCommentsOperator(d *dataTreeNavigator, matchingNodes *list.List, path
 
 	log.Debugf("AssignComments operator!")
 
-	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
-	if err != nil {
-		return nil, err
-	}
-	comment := ""
-	if rhs.Front() != nil {
-		comment = rhs.Front().Value.(*CandidateNode).Node.Value
-	}
-
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 
 	if err != nil {
@@ -34,8 +25,32 @@ func AssignCommentsOperator(d *dataTreeNavigator, matchingNodes *list.List, path
 
 	preferences := pathNode.Operation.Preferences.(*CommentOpPreferences)
 
+	comment := ""
+	if !pathNode.Operation.UpdateAssign {
+		rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
+		if err != nil {
+			return nil, err
+		}
+
+		if rhs.Front() != nil {
+			comment = rhs.Front().Value.(*CandidateNode).Node.Value
+		}
+	}
+
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
+
+		if pathNode.Operation.UpdateAssign {
+			rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+			if err != nil {
+				return nil, err
+			}
+
+			if rhs.Front() != nil {
+				comment = rhs.Front().Value.(*CandidateNode).Node.Value
+			}
+		}
+
 		log.Debugf("Setting comment of : %v", candidate.GetKey())
 		if preferences.LineComment {
 			candidate.Node.LineComment = comment

pkg/yqlib/operator_comments_test.go

@@ -13,6 +13,39 @@ var commentOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::a: cat # single\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: dog",
+		expression: `.a lineComment=.b`,
+		expected: []string{
+			"D0, P[], (doc)::a: cat # dog\nb: dog\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\n---\na: dog",
+		expression: `.a lineComment |= documentIndex`,
+		expected: []string{
+			"D0, P[], (doc)::a: cat # 0\n",
+			"D1, P[], (doc)::a: dog # 1\n",
+		},
+	},
+	{
+		description: "Use update assign to perform relative updates",
+		document:    "a: cat\nb: dog",
+		expression:  `.. lineComment |= .`,
+		expected: []string{
+			"D0, P[], (!!map)::a: cat # cat\nb: dog # dog\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "a: cat\nb: dog",
+		expression: `.. comments |= .`,
+		expected: []string{
+			"D0, P[], (!!map)::a: cat # cat\n# cat\n\n# cat\nb: dog # dog\n# dog\n\n# dog\n",
+		},
+	},
 	{
 		description: "Set head comment",
 		document:    `a: cat`,

pkg/yqlib/operator_delete.go

@@ -75,7 +75,7 @@ func deleteFromMap(candidate *CandidateNode, childPath interface{}) {
 		childCandidate := &CandidateNode{
 			Node:     value,
 			Document: candidate.Document,
-			Path:     append(candidate.Path, key.Value),
+			Path:     candidate.CreateChildPath(key.Value),
 		}
 
 		shouldDelete := key.Value == childPath

pkg/yqlib/operator_document_index_test.go

@@ -14,10 +14,27 @@ var documentIndexScenarios = []expressionScenario{
 			"D1, P[a], (!!int)::1\n",
 		},
 	},
+	{
+		description: "Retrieve a document index, shorthand",
+		document:    "a: cat\n---\na: frog\n",
+		expression:  `.a | di`,
+		expected: []string{
+			"D0, P[a], (!!int)::0\n",
+			"D1, P[a], (!!int)::1\n",
+		},
+	},
 	{
 		description: "Filter by document index",
 		document:    "a: cat\n---\na: frog\n",
-		expression:  `select(. | documentIndex == 1)`,
+		expression:  `select(documentIndex == 1)`,
+		expected: []string{
+			"D1, P[], (doc)::a: frog\n",
+		},
+	},
+	{
+		description: "Filter by document index shorthand",
+		document:    "a: cat\n---\na: frog\n",
+		expression:  `select(di == 1)`,
 		expected: []string{
 			"D1, P[], (doc)::a: frog\n",
 		},
@@ -25,7 +42,7 @@ var documentIndexScenarios = []expressionScenario{
 	{
 		description: "Print Document Index with matches",
 		document:    "a: cat\n---\na: frog\n",
-		expression:  `.a | ({"match": ., "doc": (. | documentIndex)})`,
+		expression:  `.a | ({"match": ., "doc": documentIndex})`,
 		expected: []string{
 			"D0, P[], (!!map)::match: cat\ndoc: 0\n",
 			"D0, P[], (!!map)::match: frog\ndoc: 1\n",

pkg/yqlib/operator_file_test.go

@@ -21,6 +21,14 @@ var fileOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!int)::0\n",
 		},
 	},
+	{
+		description: "Get file index alias",
+		document:    `{a: cat}`,
+		expression:  `fi`,
+		expected: []string{
+			"D0, P[], (!!int)::0\n",
+		},
+	},
 }
 
 func TestFileOperatorsScenarios(t *testing.T) {

pkg/yqlib/operator_multiply.go

@@ -85,7 +85,9 @@ func mergeObjects(d *dataTreeNavigator, lhs *CandidateNode, rhs *CandidateNode,
 	var results = list.New()
 
 	// shouldn't recurse arrays if appending
-	err := recursiveDecent(d, results, nodeToMap(rhs), !shouldAppendArrays)
+	prefs := &RecursiveDescentPreferences{RecurseArray: !shouldAppendArrays,
+		TraversePreferences: &TraversePreferences{FollowAlias: false}}
+	err := recursiveDecent(d, results, nodeToMap(rhs), prefs)
 	if err != nil {
 		return nil, err
 	}
@@ -113,7 +115,7 @@ func applyAssignment(d *dataTreeNavigator, pathIndexToStartFrom int, lhs *Candid
 	assignmentOp := &Operation{OperationType: AssignAttributes}
 	if rhs.Node.Kind == yaml.ScalarNode || rhs.Node.Kind == yaml.AliasNode {
 		assignmentOp.OperationType = Assign
-		assignmentOp.Preferences = &AssignOpPreferences{false}
+		assignmentOp.UpdateAssign = false
 	} else if shouldAppendArrays && rhs.Node.Kind == yaml.SequenceNode {
 		assignmentOp.OperationType = AddAssign
 	}

pkg/yqlib/operator_path_test.go

@@ -13,6 +13,23 @@ var pathOperatorScenarios = []expressionScenario{
 			"D0, P[a b], (!!seq)::- a\n- b\n",
 		},
 	},
+	{
+		skipDoc: true,
+		document: `a:
+  b:
+    c:
+    - 0
+    - 1
+    - 2
+    - 3`,
+		expression: `.a.b.c.[]`,
+		expected: []string{
+			"D0, P[a b c 0], (!!int)::0\n",
+			"D0, P[a b c 1], (!!int)::1\n",
+			"D0, P[a b c 2], (!!int)::2\n",
+			"D0, P[a b c 3], (!!int)::3\n",
+		},
+	},
 	{
 		description: "Get map key",
 		document:    `{a: {b: cat}}`,

pkg/yqlib/operator_recursive_descent.go

@@ -6,10 +6,16 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
+type RecursiveDescentPreferences struct {
+	TraversePreferences *TraversePreferences
+	RecurseArray        bool
+}
+
 func RecursiveDescentOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	var results = list.New()
 
-	err := recursiveDecent(d, results, matchMap, true)
+	preferences := pathNode.Operation.Preferences.(*RecursiveDescentPreferences)
+	err := recursiveDecent(d, results, matchMap, preferences)
 	if err != nil {
 		return nil, err
 	}
@@ -17,7 +23,7 @@ func RecursiveDescentOperator(d *dataTreeNavigator, matchMap *list.List, pathNod
 	return results, nil
 }
 
-func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.List, recurseArray bool) error {
+func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.List, preferences *RecursiveDescentPreferences) error {
 	for el := matchMap.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 
@@ -27,14 +33,14 @@ func recursiveDecent(d *dataTreeNavigator, results *list.List, matchMap *list.Li
 		results.PushBack(candidate)
 
 		if candidate.Node.Kind != yaml.AliasNode && len(candidate.Node.Content) > 0 &&
-			(recurseArray || candidate.Node.Kind != yaml.SequenceNode) {
+			(preferences.RecurseArray || candidate.Node.Kind != yaml.SequenceNode) {
 
-			children, err := Splat(d, nodeToMap(candidate))
+			children, err := Splat(d, nodeToMap(candidate), preferences.TraversePreferences)
 
 			if err != nil {
 				return err
 			}
-			err = recursiveDecent(d, results, children, recurseArray)
+			err = recursiveDecent(d, results, children, preferences)
 			if err != nil {
 				return err
 			}

pkg/yqlib/operator_recursive_descent_test.go

@@ -13,6 +13,14 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::{}\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `{}`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!map)::{}\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `[]`,
@@ -21,6 +29,14 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!seq)::[]\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `[]`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!seq)::[]\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `cat`,
@@ -31,6 +47,14 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 	},
 	{
 		skipDoc:    true,
+		document:   `cat`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!str)::cat\n",
+		},
+	},
+	{
+		description: "Recurse map (values only)",
 		document:    `{a: frog}`,
 		expression:  `..`,
 		expected: []string{
@@ -38,6 +62,17 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[a], (!!str)::frog\n",
 		},
 	},
+	{
+		description:    "Recurse map (values and keys)",
+		subdescription: "Note that the map key appears in the results",
+		document:       `{a: frog}`,
+		expression:     `...`,
+		expected: []string{
+			"D0, P[], (!!map)::{a: frog}\n",
+			"D0, P[a], (!!str)::a\n",
+			"D0, P[a], (!!str)::frog\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `{a: {b: apple}}`,
@@ -48,6 +83,18 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[a b], (!!str)::apple\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `{a: {b: apple}}`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!map)::{a: {b: apple}}\n",
+			"D0, P[a], (!!str)::a\n",
+			"D0, P[a], (!!map)::{b: apple}\n",
+			"D0, P[a b], (!!str)::b\n",
+			"D0, P[a b], (!!str)::apple\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `[1,2,3]`,
@@ -59,6 +106,17 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[2], (!!int)::3\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `[1,2,3]`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!seq)::[1, 2, 3]\n",
+			"D0, P[0], (!!int)::1\n",
+			"D0, P[1], (!!int)::2\n",
+			"D0, P[2], (!!int)::3\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `[{a: cat},2,true]`,
@@ -71,6 +129,19 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[2], (!!bool)::true\n",
 		},
 	},
+	{
+		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",
+			"D0, P[0 a], (!!str)::a\n",
+			"D0, P[0 a], (!!str)::cat\n",
+			"D0, P[1], (!!int)::2\n",
+			"D0, P[2], (!!bool)::true\n",
+		},
+	},
 	{
 		description: "Aliases are not traversed",
 		document:    `{a: &cat {c: frog}, b: *cat}`,
@@ -79,6 +150,20 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[a], (!!seq)::- {a: &cat {c: frog}, b: *cat}\n- &cat {c: frog}\n- frog\n- *cat\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `{a: &cat {c: frog}, b: *cat}`,
+		expression: `...`,
+		expected: []string{
+			"D0, P[], (!!map)::{a: &cat {c: frog}, b: *cat}\n",
+			"D0, P[a], (!!str)::a\n",
+			"D0, P[a], (!!map)::&cat {c: frog}\n",
+			"D0, P[a c], (!!str)::c\n",
+			"D0, P[a c], (!!str)::frog\n",
+			"D0, P[b], (!!str)::b\n",
+			"D0, P[b], (alias)::*cat\n",
+		},
+	},
 	{
 		description: "Merge docs are not traversed",
 		document:    mergeDocSample,
@@ -87,6 +172,14 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[foobar], (!!seq)::- c: foobar_c\n  !!merge <<: *foo\n  thing: foobar_thing\n- foobar_c\n- *foo\n- foobar_thing\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
+		expression: `.foobar | [...]`,
+		expected: []string{
+			"D0, P[foobar], (!!seq)::- c: foobar_c\n  !!merge <<: *foo\n  thing: foobar_thing\n- c\n- foobar_c\n- !!merge <<\n- *foo\n- thing\n- foobar_thing\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   mergeDocSample,
@@ -100,6 +193,22 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[foobarList c], (!!str)::foobarList_c\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
+		expression: `.foobarList | ...`,
+		expected: []string{
+			"D0, P[foobarList], (!!map)::b: foobarList_b\n!!merge <<: [*foo, *bar]\nc: foobarList_c\n",
+			"D0, P[foobarList b], (!!str)::b\n",
+			"D0, P[foobarList b], (!!str)::foobarList_b\n",
+			"D0, P[foobarList <<], (!!merge)::!!merge <<\n",
+			"D0, P[foobarList <<], (!!seq)::[*foo, *bar]\n",
+			"D0, P[foobarList << 0], (alias)::*foo\n",
+			"D0, P[foobarList << 1], (alias)::*bar\n",
+			"D0, P[foobarList c], (!!str)::c\n",
+			"D0, P[foobarList c], (!!str)::foobarList_c\n",
+		},
+	},
 }
 
 func TestRecursiveDescentOperatorScenarios(t *testing.T) {

pkg/yqlib/operator_style.go

@@ -4,39 +4,46 @@ import (
 	"container/list"
 	"fmt"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
+func parseStyle(customStyle string) (yaml.Style, error) {
+	if customStyle == "tagged" {
+		return yaml.TaggedStyle, nil
+	} else if customStyle == "double" {
+		return yaml.DoubleQuotedStyle, nil
+	} else if customStyle == "single" {
+		return yaml.SingleQuotedStyle, nil
+	} else if customStyle == "literal" {
+		return yaml.LiteralStyle, nil
+	} else if customStyle == "folded" {
+		return yaml.FoldedStyle, nil
+	} else if customStyle == "flow" {
+		return yaml.FlowStyle, nil
+	} else if customStyle != "" {
+		return 0, fmt.Errorf("Unknown style %v", customStyle)
+	}
+	return 0, nil
+}
+
 func AssignStyleOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 
 	log.Debugf("AssignStyleOperator: %v")
-
+	var style yaml.Style
+	if !pathNode.Operation.UpdateAssign {
 		rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 		if err != nil {
 			return nil, err
 		}
-	customStyle := ""
 
 		if rhs.Front() != nil {
-		customStyle = rhs.Front().Value.(*CandidateNode).Node.Value
+			style, err = parseStyle(rhs.Front().Value.(*CandidateNode).Node.Value)
+			if err != nil {
+				return nil, err
+			}
+		}
 	}
 
-	var style yaml.Style
-	if customStyle == "tagged" {
-		style = yaml.TaggedStyle
-	} else if customStyle == "double" {
-		style = yaml.DoubleQuotedStyle
-	} else if customStyle == "single" {
-		style = yaml.SingleQuotedStyle
-	} else if customStyle == "literal" {
-		style = yaml.LiteralStyle
-	} else if customStyle == "folded" {
-		style = yaml.FoldedStyle
-	} else if customStyle == "flow" {
-		style = yaml.FlowStyle
-	} else if customStyle != "" {
-		return nil, fmt.Errorf("Unknown style %v", customStyle)
-	}
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 
 	if err != nil {
@@ -46,6 +53,20 @@ func AssignStyleOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNod
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		log.Debugf("Setting style of : %v", candidate.GetKey())
+		if pathNode.Operation.UpdateAssign {
+			rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+			if err != nil {
+				return nil, err
+			}
+
+			if rhs.Front() != nil {
+				style, err = parseStyle(rhs.Front().Value.(*CandidateNode).Node.Value)
+				if err != nil {
+					return nil, err
+				}
+			}
+		}
+
 		candidate.Node.Style = style
 	}
 

pkg/yqlib/operator_style_test.go

@@ -21,6 +21,22 @@ var styleOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::a: \"cat\"\nb: \"5\"\nc: \"3.2\"\ne: \"true\"\n",
 		},
 	},
+	{
+		description: "Set double quote style on map keys too",
+		document:    `{a: cat, b: 5, c: 3.2, e: true}`,
+		expression:  `... style="double"`,
+		expected: []string{
+			"D0, P[], (!!map)::\"a\": \"cat\"\n\"b\": \"5\"\n\"c\": \"3.2\"\n\"e\": \"true\"\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "bing: &foo frog\na:\n  c: cat\n  <<: [*foo]",
+		expression: `(... | select(tag=="!!str")) style="single"`,
+		expected: []string{
+			"D0, P[], (!!map)::'bing': &foo 'frog'\n'a':\n    'c': 'cat'\n    !!merge <<: [*foo]\n",
+		},
+	},
 	{
 		description: "Set single quote style",
 		document:    `{a: cat, b: 5, c: 3.2, e: true}`,
@@ -70,14 +86,22 @@ e: >-
 		},
 	},
 	{
-		description:    "Pretty print",
-		subdescription: "Set empty (default) quote style",
-		document:       `{a: cat, b: 5, c: 3.2, e: true}`,
-		expression:     `.. style=""`,
+		description:    "Reset style - or pretty print",
+		subdescription: "Set empty (default) quote style, note the usage of `...` to match keys too. Note that there is a `--prettyPrint/-P` short flag for this.",
+		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",
 		},
 	},
+	{
+		description: "Set style relatively with assign-update",
+		document:    `{a: single, b: double}`,
+		expression:  `.[] style |= .`,
+		expected: []string{
+			"D0, P[], (doc)::{a: 'single', b: \"double\"}\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `{a: cat, b: double}`,

pkg/yqlib/operator_tag.go

@@ -3,22 +3,24 @@ package yqlib
 import (
 	"container/list"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 func AssignTagOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
 
 	log.Debugf("AssignTagOperator: %v")
+	tag := ""
 
+	if !pathNode.Operation.UpdateAssign {
 		rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 		if err != nil {
 			return nil, err
 		}
-	tag := ""
 
 		if rhs.Front() != nil {
 			tag = rhs.Front().Value.(*CandidateNode).Node.Value
 		}
+	}
 
 	lhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Lhs)
 
@@ -29,6 +31,16 @@ func AssignTagOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode
 	for el := lhs.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		log.Debugf("Setting tag of : %v", candidate.GetKey())
+		if pathNode.Operation.UpdateAssign {
+			rhs, err := d.GetMatchingNodes(nodeToMap(candidate), pathNode.Rhs)
+			if err != nil {
+				return nil, err
+			}
+
+			if rhs.Front() != nil {
+				tag = rhs.Front().Value.(*CandidateNode).Node.Value
+			}
+		}
 		candidate.Node.Tag = tag
 	}
 
@@ -42,7 +54,7 @@ func GetTagOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *Pa
 
 	for el := matchingNodes.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
-		node := &yaml.Node{Kind: yaml.ScalarNode, Value: candidate.Node.Tag, Tag: "!!str"}
+		node := &yaml.Node{Kind: yaml.ScalarNode, Value: UnwrapDoc(candidate.Node).Tag, Tag: "!!str"}
 		lengthCand := &CandidateNode{Node: node, Document: candidate.Document, Path: candidate.Path}
 		results.PushBack(lengthCand)
 	}

pkg/yqlib/operator_tag_test.go

@@ -19,13 +19,37 @@ var tagOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		description: "Convert numbers to strings",
+		skipDoc:    true,
+		document:   `{a: cat, b: 5, c: 3.2, e: true, f: []}`,
+		expression: `tag`,
+		expected: []string{
+			"D0, P[], (!!str)::'!!map'\n",
+		},
+	},
+	{
+		description: "Set custom tag",
+		document:    `{a: str}`,
+		expression:  `.a tag = "!!mikefarah"`,
+		expected: []string{
+			"D0, P[], (doc)::{a: !!mikefarah str}\n",
+		},
+	},
+	{
+		description: "Find numbers and convert them to strings",
 		document:    `{a: cat, b: 5, c: 3.2, e: true}`,
 		expression:  `(.. | select(tag == "!!int")) tag= "!!str"`,
 		expected: []string{
 			"D0, P[], (!!map)::{a: cat, b: \"5\", c: 3.2, e: true}\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `{a: "!!frog", b: "!!customTag"}`,
+		expression: `.[] tag |= .`,
+		expected: []string{
+			"D0, P[], (doc)::{a: !!frog \"!!frog\", b: !!customTag \"!!customTag\"}\n",
+		},
+	},
 }
 
 func TestTagOperatorScenarios(t *testing.T) {

pkg/yqlib/operator_traverse_path.go

@@ -1,46 +1,39 @@
 package yqlib
 
 import (
-	"fmt"
-
 	"container/list"
+	"fmt"
+	"strconv"
 
 	"github.com/elliotchance/orderedmap"
-
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type TraversePreferences struct {
-	DontFollowAlias bool
+	FollowAlias    bool
+	IncludeMapKeys bool
 }
 
-func Splat(d *dataTreeNavigator, matches *list.List) (*list.List, error) {
-	preferences := &TraversePreferences{DontFollowAlias: true}
-	splatOperation := &Operation{OperationType: TraversePath, Value: "[]", Preferences: preferences}
-	splatTreeNode := &PathTreeNode{Operation: splatOperation}
-	return TraversePathOperator(d, matches, splatTreeNode)
+func Splat(d *dataTreeNavigator, matches *list.List, prefs *TraversePreferences) (*list.List, error) {
+	return traverseNodesWithArrayIndices(matches, make([]*yaml.Node, 0), prefs)
 }
 
 func TraversePathOperator(d *dataTreeNavigator, matchMap *list.List, pathNode *PathTreeNode) (*list.List, error) {
 	log.Debugf("-- Traversing")
 	var matchingNodeMap = list.New()
-	var newNodes []*CandidateNode
-	var err error
 
 	for el := matchMap.Front(); el != nil; el = el.Next() {
-		newNodes, err = traverse(d, el.Value.(*CandidateNode), pathNode.Operation)
+		newNodes, err := traverse(d, el.Value.(*CandidateNode), pathNode.Operation)
 		if err != nil {
 			return nil, err
 		}
-		for _, n := range newNodes {
-			matchingNodeMap.PushBack(n)
-		}
+		matchingNodeMap.PushBackList(newNodes)
 	}
 
 	return matchingNodeMap, nil
 }
 
-func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Operation) ([]*CandidateNode, error) {
+func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Operation) (*list.List, error) {
 	log.Debug("Traversing %v", NodeToString(matchingNode))
 	value := matchingNode.Node
 
@@ -61,34 +54,8 @@ func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Oper
 	switch value.Kind {
 	case yaml.MappingNode:
 		log.Debug("its a map with %v entries", len(value.Content)/2)
-		var newMatches = orderedmap.NewOrderedMap()
-		err := traverseMap(newMatches, matchingNode, operation)
-
-		if err != nil {
-			return nil, err
-		}
-
-		if newMatches.Len() == 0 {
-			//no matches, create one automagically
-			valueNode := &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"}
-			node := matchingNode.Node
-			node.Content = append(node.Content, &yaml.Node{Kind: yaml.ScalarNode, Value: operation.StringValue}, valueNode)
-			candidateNode := &CandidateNode{
-				Node:     valueNode,
-				Path:     append(matchingNode.Path, operation.StringValue),
-				Document: matchingNode.Document,
-			}
-			newMatches.Set(candidateNode.GetKey(), candidateNode)
-
-		}
-
-		arrayMatches := make([]*CandidateNode, newMatches.Len())
-		i := 0
-		for el := newMatches.Front(); el != nil; el = el.Next() {
-			arrayMatches[i] = el.Value.(*CandidateNode)
-			i++
-		}
-		return arrayMatches, nil
+		prefs := &TraversePreferences{FollowAlias: true}
+		return traverseMap(matchingNode, operation.StringValue, prefs, false)
 
 	case yaml.SequenceNode:
 		log.Debug("its a sequence of %v things!", len(value.Content))
@@ -102,104 +69,117 @@ func traverse(d *dataTreeNavigator, matchingNode *CandidateNode, operation *Oper
 		log.Debug("digging into doc node")
 		return traverse(d, &CandidateNode{
 			Node:      matchingNode.Node.Content[0],
+			Filename:  matchingNode.Filename,
+			FileIndex: matchingNode.FileIndex,
 			Document:  matchingNode.Document}, operation)
 	default:
-		return nil, nil
+		return list.New(), nil
 	}
 }
 
-func keyMatches(key *yaml.Node, pathNode *Operation) bool {
-	return pathNode.Value == "[]" || Match(key.Value, pathNode.StringValue)
-}
+func TraverseArrayOperator(d *dataTreeNavigator, matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
+	// rhs is a collect expression that will yield indexes to retreive of the arrays
 
-func traverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode, operation *Operation) error {
-	// value.Content is a concatenated array of key, value,
-	// so keys are in the even indexes, values in odd.
-	// merge aliases are defined first, but we only want to traverse them
-	// if we don't find a match directly on this node first.
-	//TODO ALIASES, auto creation?
-
-	node := candidate.Node
-
-	followAlias := true
-
-	if operation.Preferences != nil {
-		followAlias = !operation.Preferences.(*TraversePreferences).DontFollowAlias
-	}
-
-	var contents = node.Content
-	for index := 0; index < len(contents); index = index + 2 {
-		key := contents[index]
-		value := contents[index+1]
-
-		log.Debug("checking %v (%v)", key.Value, key.Tag)
-		//skip the 'merge' tag, find a direct match first
-		if key.Tag == "!!merge" && followAlias {
-			log.Debug("Merge anchor")
-			err := traverseMergeAnchor(newMatches, candidate, value, operation)
+	rhs, err := d.GetMatchingNodes(matchingNodes, pathNode.Rhs)
 	if err != nil {
-				return err
-			}
-		} else if keyMatches(key, operation) {
-			log.Debug("MATCHED")
-			candidateNode := &CandidateNode{
-				Node:     value,
-				Path:     append(candidate.Path, key.Value),
-				Document: candidate.Document,
-			}
-			newMatches.Set(candidateNode.GetKey(), candidateNode)
-		}
+		return nil, err
 	}
 
-	return nil
+	var indicesToTraverse = rhs.Front().Value.(*CandidateNode).Node.Content
+	prefs := &TraversePreferences{FollowAlias: true}
+	return traverseNodesWithArrayIndices(matchingNodes, indicesToTraverse, prefs)
 }
 
-func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *CandidateNode, value *yaml.Node, operation *Operation) error {
-	switch value.Kind {
-	case yaml.AliasNode:
-		candidateNode := &CandidateNode{
-			Node:     value.Alias,
-			Path:     originalCandidate.Path,
-			Document: originalCandidate.Document,
-		}
-		return traverseMap(newMatches, candidateNode, operation)
-	case yaml.SequenceNode:
-		for _, childValue := range value.Content {
-			err := traverseMergeAnchor(newMatches, originalCandidate, childValue, operation)
+func traverseNodesWithArrayIndices(matchingNodes *list.List, indicesToTraverse []*yaml.Node, prefs *TraversePreferences) (*list.List, error) {
+	var matchingNodeMap = list.New()
+	for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		newNodes, err := traverseArrayIndices(candidate, indicesToTraverse, prefs)
 		if err != nil {
-				return err
+			return nil, err
 		}
-		}
-	}
-	return nil
+		matchingNodeMap.PushBackList(newNodes)
 	}
 
-func traverseArray(candidate *CandidateNode, operation *Operation) ([]*CandidateNode, error) {
-	log.Debug("operation Value %v", operation.Value)
-	if operation.Value == "[]" {
+	return matchingNodeMap, nil
+}
 
-		var contents = candidate.Node.Content
-		var newMatches = make([]*CandidateNode, len(contents))
+func traverseArrayIndices(matchingNode *CandidateNode, indicesToTraverse []*yaml.Node, prefs *TraversePreferences) (*list.List, error) { // call this if doc / alias like the other traverse
+	node := matchingNode.Node
+	if node.Tag == "!!null" {
+		log.Debugf("OperatorArrayTraverse got a null - turning it into an empty array")
+		// auto vivification, make it into an empty array
+		node.Tag = ""
+		node.Kind = yaml.SequenceNode
+	}
+
+	if node.Kind == yaml.AliasNode {
+		matchingNode.Node = node.Alias
+		return traverseArrayIndices(matchingNode, indicesToTraverse, prefs)
+	} else if node.Kind == yaml.SequenceNode {
+		return traverseArrayWithIndices(matchingNode, indicesToTraverse)
+	} else if node.Kind == yaml.MappingNode {
+		return traverseMapWithIndices(matchingNode, indicesToTraverse, prefs)
+	} else if node.Kind == yaml.DocumentNode {
+		return traverseArrayIndices(&CandidateNode{
+			Node:      matchingNode.Node.Content[0],
+			Filename:  matchingNode.Filename,
+			FileIndex: matchingNode.FileIndex,
+			Document:  matchingNode.Document}, indicesToTraverse, prefs)
+	}
+	log.Debugf("OperatorArrayTraverse skipping %v as its a %v", matchingNode, node.Tag)
+	return list.New(), nil
+}
+
+func traverseMapWithIndices(candidate *CandidateNode, indices []*yaml.Node, prefs *TraversePreferences) (*list.List, error) {
+	if len(indices) == 0 {
+		return traverseMap(candidate, "", prefs, true)
+	}
+
+	var matchingNodeMap = list.New()
+
+	for _, indexNode := range indices {
+		log.Debug("traverseMapWithIndices: %v", indexNode.Value)
+		newNodes, err := traverseMap(candidate, indexNode.Value, prefs, false)
+		if err != nil {
+			return nil, err
+		}
+		matchingNodeMap.PushBackList(newNodes)
+	}
+
+	return matchingNodeMap, nil
+}
+
+func traverseArrayWithIndices(candidate *CandidateNode, indices []*yaml.Node) (*list.List, error) {
+	log.Debug("traverseArrayWithIndices")
+	var newMatches = list.New()
+	node := UnwrapDoc(candidate.Node)
+	if len(indices) == 0 {
+		log.Debug("splatting")
 		var index int64
-		for index = 0; index < int64(len(contents)); index = index + 1 {
-			newMatches[index] = &CandidateNode{
+		for index = 0; index < int64(len(node.Content)); index = index + 1 {
+
+			newMatches.PushBack(&CandidateNode{
 				Document: candidate.Document,
-				Path:     append(candidate.Path, index),
-				Node:     contents[index],
-			}
+				Path:     candidate.CreateChildPath(index),
+				Node:     node.Content[index],
+			})
 		}
 		return newMatches, nil
 
 	}
 
-	switch operation.Value.(type) {
-	case int64:
-		index := operation.Value.(int64)
+	for _, indexNode := range indices {
+		log.Debug("traverseArrayWithIndices: '%v'", indexNode.Value)
+		index, err := strconv.ParseInt(indexNode.Value, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("Cannot index array with '%v' (%v)", indexNode.Value, err)
+		}
 		indexToUse := index
-		contentLength := int64(len(candidate.Node.Content))
+		contentLength := int64(len(node.Content))
 		for contentLength <= index {
-			candidate.Node.Content = append(candidate.Node.Content, &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"})
-			contentLength = int64(len(candidate.Node.Content))
+			node.Content = append(node.Content, &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"})
+			contentLength = int64(len(node.Content))
 		}
 
 		if indexToUse < 0 {
@@ -210,14 +190,115 @@ func traverseArray(candidate *CandidateNode, operation *Operation) ([]*Candidate
 			return nil, fmt.Errorf("Index [%v] out of range, array size is %v", index, contentLength)
 		}
 
-		return []*CandidateNode{&CandidateNode{
-			Node:     candidate.Node.Content[indexToUse],
+		newMatches.PushBack(&CandidateNode{
+			Node:     node.Content[indexToUse],
 			Document: candidate.Document,
-			Path:     append(candidate.Path, index),
-		}}, nil
-	default:
-		log.Debug("argument not an int (%v), no array matches", operation.Value)
-		return nil, nil
+			Path:     candidate.CreateChildPath(index),
+		})
+	}
+	return newMatches, nil
 }
 
+func keyMatches(key *yaml.Node, wantedKey string) bool {
+	return Match(key.Value, wantedKey)
+}
+
+func traverseMap(matchingNode *CandidateNode, key string, prefs *TraversePreferences, splat bool) (*list.List, error) {
+	var newMatches = orderedmap.NewOrderedMap()
+	err := doTraverseMap(newMatches, matchingNode, key, prefs, splat)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if newMatches.Len() == 0 {
+		//no matches, create one automagically
+		valueNode := &yaml.Node{Tag: "!!null", Kind: yaml.ScalarNode, Value: "null"}
+		node := matchingNode.Node
+		node.Content = append(node.Content, &yaml.Node{Kind: yaml.ScalarNode, Value: key}, valueNode)
+		candidateNode := &CandidateNode{
+			Node:     valueNode,
+			Path:     append(matchingNode.Path, key),
+			Document: matchingNode.Document,
+		}
+		newMatches.Set(candidateNode.GetKey(), candidateNode)
+
+	}
+
+	results := list.New()
+	i := 0
+	for el := newMatches.Front(); el != nil; el = el.Next() {
+		results.PushBack(el.Value)
+		i++
+	}
+	return results, nil
+}
+
+func doTraverseMap(newMatches *orderedmap.OrderedMap, candidate *CandidateNode, wantedKey string, prefs *TraversePreferences, splat bool) error {
+	// value.Content is a concatenated array of key, value,
+	// so keys are in the even indexes, values in odd.
+	// merge aliases are defined first, but we only want to traverse them
+	// if we don't find a match directly on this node first.
+
+	node := candidate.Node
+
+	var contents = node.Content
+	for index := 0; index < len(contents); index = index + 2 {
+		key := contents[index]
+		value := contents[index+1]
+
+		log.Debug("checking %v (%v)", key.Value, key.Tag)
+		//skip the 'merge' tag, find a direct match first
+		if key.Tag == "!!merge" && prefs.FollowAlias {
+			log.Debug("Merge anchor")
+			err := traverseMergeAnchor(newMatches, candidate, value, wantedKey, prefs, splat)
+			if err != nil {
+				return err
+			}
+		} else if splat || keyMatches(key, wantedKey) {
+			log.Debug("MATCHED")
+			if prefs.IncludeMapKeys {
+				candidateNode := &CandidateNode{
+					Node:     key,
+					Path:     candidate.CreateChildPath(key.Value),
+					Document: candidate.Document,
+				}
+				newMatches.Set(fmt.Sprintf("keyOf-%v", candidateNode.GetKey()), candidateNode)
+			}
+			candidateNode := &CandidateNode{
+				Node:     value,
+				Path:     candidate.CreateChildPath(key.Value),
+				Document: candidate.Document,
+			}
+			newMatches.Set(candidateNode.GetKey(), candidateNode)
+		}
+	}
+
+	return nil
+}
+
+func traverseMergeAnchor(newMatches *orderedmap.OrderedMap, originalCandidate *CandidateNode, value *yaml.Node, wantedKey string, prefs *TraversePreferences, splat bool) error {
+	switch value.Kind {
+	case yaml.AliasNode:
+		candidateNode := &CandidateNode{
+			Node:     value.Alias,
+			Path:     originalCandidate.Path,
+			Document: originalCandidate.Document,
+		}
+		return doTraverseMap(newMatches, candidateNode, wantedKey, prefs, splat)
+	case yaml.SequenceNode:
+		for _, childValue := range value.Content {
+			err := traverseMergeAnchor(newMatches, originalCandidate, childValue, wantedKey, prefs, splat)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func traverseArray(candidate *CandidateNode, operation *Operation) (*list.List, error) {
+	log.Debug("operation Value %v", operation.Value)
+	indices := []*yaml.Node{&yaml.Node{Value: operation.StringValue}}
+	return traverseArrayWithIndices(candidate, indices)
 }

pkg/yqlib/operator_traverse_path_test.go

@@ -65,7 +65,7 @@ var traversePathOperatorScenarios = []expressionScenario{
 	},
 	{
 		skipDoc:    true,
-		document:   `{}`,
+		document:   ``,
 		expression: `.[1].a`,
 		expected: []string{
 			"D0, P[1 a], (!!null)::null\n",
@@ -137,6 +137,14 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Traversing aliases with splat",
 		document:    `{a: &cat {c: frog}, b: *cat}`,
+		expression:  `.b[]`,
+		expected: []string{
+			"D0, P[b c], (!!str)::frog\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: &cat {c: frog}, b: *cat}`,
 		expression: `.b.[]`,
 		expected: []string{
 			"D0, P[b c], (!!str)::frog\n",
@@ -150,12 +158,6 @@ var traversePathOperatorScenarios = []expressionScenario{
 			"D0, P[b c], (!!str)::frog\n",
 		},
 	},
-	{
-		skipDoc:    true,
-		document:   `[1,2,3]`,
-		expression: `.b`,
-		expected:   []string{},
-	},
 	{
 		description: "Traversing arrays by index",
 		document:    `[1,2,3]`,
@@ -215,6 +217,16 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Splatting merge anchors",
 		document:    mergeDocSample,
+		expression:  `.foobar[]`,
+		expected: []string{
+			"D0, P[foobar c], (!!str)::foo_c\n",
+			"D0, P[foobar a], (!!str)::foo_a\n",
+			"D0, P[foobar thing], (!!str)::foobar_thing\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
 		expression: `.foobar.[]`,
 		expected: []string{
 			"D0, P[foobar c], (!!str)::foo_c\n",
@@ -266,6 +278,17 @@ var traversePathOperatorScenarios = []expressionScenario{
 	{
 		description: "Splatting merge anchor lists",
 		document:    mergeDocSample,
+		expression:  `.foobarList[]`,
+		expected: []string{
+			"D0, P[foobarList b], (!!str)::bar_b\n",
+			"D0, P[foobarList a], (!!str)::foo_a\n",
+			"D0, P[foobarList thing], (!!str)::bar_thing\n",
+			"D0, P[foobarList c], (!!str)::foobarList_c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   mergeDocSample,
 		expression: `.foobarList.[]`,
 		expected: []string{
 			"D0, P[foobarList b], (!!str)::bar_b\n",
@@ -274,6 +297,112 @@ var traversePathOperatorScenarios = []expressionScenario{
 			"D0, P[foobarList c], (!!str)::foobarList_c\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `[a,b,c]`,
+		expression: `.[]`,
+		expected: []string{
+			"D0, P[0], (!!str)::a\n",
+			"D0, P[1], (!!str)::b\n",
+			"D0, P[2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `[a,b,c]`,
+		expression: `[]`,
+		expected: []string{
+			"D0, P[], (!!seq)::[]\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[0]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+		},
+	},
+	{
+		description: "Select multiple indices",
+		document:    `{a: [a,b,c]}`,
+		expression:  `.a[0, 2]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[0, 2]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[-1]`,
+		expected: []string{
+			"D0, P[a -1], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[-1]`,
+		expected: []string{
+			"D0, P[a -1], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[-2]`,
+		expected: []string{
+			"D0, P[a -2], (!!str)::b\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[-2]`,
+		expected: []string{
+			"D0, P[a -2], (!!str)::b\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a.[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   `{a: [a,b,c]}`,
+		expression: `.a | .[]`,
+		expected: []string{
+			"D0, P[a 0], (!!str)::a\n",
+			"D0, P[a 1], (!!str)::b\n",
+			"D0, P[a 2], (!!str)::c\n",
+		},
+	},
 }
 
 func TestTraversePathOperatorScenarios(t *testing.T) {

pkg/yqlib/operators_test.go

@@ -18,6 +18,7 @@ type expressionScenario struct {
 	description           string
 	subdescription        string
 	document              string
+	document2             string
 	expression            string
 	expected              []string
 	skipDoc               bool
@@ -38,9 +39,17 @@ func testScenario(t *testing.T, s *expressionScenario) {
 	if s.document != "" {
 		inputs, err = readDocuments(strings.NewReader(s.document), "sample.yml", 0)
 		if err != nil {
-			t.Error(err, s.document)
+			t.Error(err, s.document, s.expression)
 			return
 		}
+		if s.document2 != "" {
+			moreInputs, err := readDocuments(strings.NewReader(s.document2), "another.yml", 1)
+			if err != nil {
+				t.Error(err, s.document, s.expression)
+				return
+			}
+			inputs.PushBackList(moreInputs)
+		}
 	} else {
 		candidateNode := &CandidateNode{
 			Document:  0,
@@ -55,7 +64,7 @@ func testScenario(t *testing.T, s *expressionScenario) {
 	results, err = treeNavigator.GetMatchingNodes(inputs, node)
 
 	if err != nil {
-		t.Error(err)
+		t.Error(fmt.Errorf("%v: %v", err, s.expression))
 		return
 	}
 	test.AssertResultComplexWithContext(t, s.expected, resultsToString(results), fmt.Sprintf("exp: %v\ndoc: %v", s.expression, s.document))
@@ -92,7 +101,7 @@ func copyFromHeader(title string, out *os.File) error {
 	return err
 }
 
-func formatYaml(yaml string) string {
+func formatYaml(yaml string, filename string) string {
 	var output bytes.Buffer
 	printer := NewPrinter(bufio.NewWriter(&output), false, true, false, 2, true)
 
@@ -101,7 +110,7 @@ func formatYaml(yaml string) string {
 		panic(err)
 	}
 	streamEvaluator := NewStreamEvaluator()
-	err = streamEvaluator.Evaluate("sample.yaml", strings.NewReader(yaml), node, printer)
+	err = streamEvaluator.Evaluate(filename, strings.NewReader(yaml), node, printer)
 	if err != nil {
 		panic(err)
 	}
@@ -128,63 +137,116 @@ func documentScenarios(t *testing.T, title string, scenarios []expressionScenari
 
 	for _, s := range scenarios {
 		if !s.skipDoc {
+			documentScenario(t, w, s)
+		}
+	}
+	w.Flush()
+}
 
+func documentScenario(t *testing.T, w *bufio.Writer, s expressionScenario) {
 	writeOrPanic(w, fmt.Sprintf("## %v\n", s.description))
 
 	if s.subdescription != "" {
 		writeOrPanic(w, s.subdescription)
 		writeOrPanic(w, "\n\n")
 	}
+
+	formattedDoc, formattedDoc2 := documentInput(w, s)
+
+	writeOrPanic(w, "will output\n")
+
+	documentOutput(t, w, s, formattedDoc, formattedDoc2)
+}
+
+func documentInput(w *bufio.Writer, s expressionScenario) (string, string) {
 	formattedDoc := ""
+	formattedDoc2 := ""
+	command := "eval"
 	if s.document != "" {
 		if s.dontFormatInputForDoc {
 			formattedDoc = s.document + "\n"
 		} else {
-					formattedDoc = formatYaml(s.document)
+			formattedDoc = formatYaml(s.document, "sample.yml")
 		}
-				//TODO: pretty here
-				writeOrPanic(w, "Given a sample.yml file of:\n")
 
+		writeOrPanic(w, "Given a sample.yml file of:\n")
 		writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n", formattedDoc))
+
+		files := "sample.yml"
+
+		if s.document2 != "" {
+			if s.dontFormatInputForDoc {
+				formattedDoc2 = s.document2 + "\n"
+			} else {
+				formattedDoc2 = formatYaml(s.document2, "another.yml")
+			}
+
+			writeOrPanic(w, "And another sample another.yml file of:\n")
+			writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n", formattedDoc2))
+			files = "sample.yml another.yml"
+			command = "eval-all"
+		}
+
 		writeOrPanic(w, "then\n")
 		if s.expression != "" {
-					writeOrPanic(w, fmt.Sprintf("```bash\nyq eval '%v' sample.yml\n```\n", s.expression))
+			writeOrPanic(w, fmt.Sprintf("```bash\nyq %v '%v' %v\n```\n", command, s.expression, files))
 		} else {
-					writeOrPanic(w, "```bash\nyq eval sample.yml\n```\n")
+			writeOrPanic(w, fmt.Sprintf("```bash\nyq %v %v\n```\n", command, files))
 		}
 	} else {
 		writeOrPanic(w, "Running\n")
-				writeOrPanic(w, fmt.Sprintf("```bash\nyq eval --null-input '%v'\n```\n", s.expression))
+		writeOrPanic(w, fmt.Sprintf("```bash\nyq %v --null-input '%v'\n```\n", command, s.expression))
+	}
+	return formattedDoc, formattedDoc2
 }
 
-			writeOrPanic(w, "will output\n")
-
+func documentOutput(t *testing.T, w *bufio.Writer, s expressionScenario, formattedDoc string, formattedDoc2 string) {
 	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)
+		t.Error(fmt.Errorf("Error parsing expression %v of %v: %v", s.expression, s.description, err))
+		return
 	}
-				err = streamEvaluator.Evaluate("sample.yaml", strings.NewReader(formattedDoc), node, printer)
 
+	inputs := list.New()
+
+	if s.document != "" {
+		inputs, err = readDocuments(strings.NewReader(formattedDoc), "sample.yml", 0)
 		if err != nil {
-					t.Error(err)
+			t.Error(err, s.document, s.expression)
+			return
+		}
+		if s.document2 != "" {
+			moreInputs, err := readDocuments(strings.NewReader(formattedDoc2), "another.yml", 1)
+			if err != nil {
+				t.Error(err, s.document, s.expression)
+				return
+			}
+			inputs.PushBackList(moreInputs)
 		}
 	} else {
-				err = streamEvaluator.EvaluateNew(s.expression, printer)
-				if err != nil {
-					t.Error(err)
+		candidateNode := &CandidateNode{
+			Document:  0,
+			Filename:  "",
+			Node:      &yaml.Node{Tag: "!!null"},
+			FileIndex: 0,
 		}
+		inputs.PushBack(candidateNode)
+
+	}
+
+	results, err := treeNavigator.GetMatchingNodes(inputs, node)
+	if err != nil {
+		t.Error(err, s.expression)
+	}
+
+	err = printer.PrintResults(results)
+	if err != nil {
+		t.Error(err, s.expression)
 	}
 
 	writeOrPanic(w, fmt.Sprintf("```yaml\n%v```\n\n", output.String()))
-
-		}
-
-	}
-	w.Flush()
 }

pkg/yqlib/path_parse_test.go

@@ -17,20 +17,35 @@ var pathTests = []struct {
 		append(make([]interface{}, 0), "[", "]"),
 		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE"),
 	},
+	{
+		`.[]`,
+		append(make([]interface{}, 0), "TRAVERSE_ARRAY", "[", "]"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
 	{
 		`.a[]`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
 	},
 	{
 		`.a.[]`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
+	},
+	{
+		`.a[0]`,
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
+	},
+	{
+		`.a.[0]`,
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE"),
 	},
 	{
 		`.a[].c`,
-		append(make([]interface{}, 0), "a", "SHORT_PIPE", "[]", "SHORT_PIPE", "c"),
-		append(make([]interface{}, 0), "a", "[]", "SHORT_PIPE", "c", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "c"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "c", "SHORT_PIPE"),
 	},
 	{
 		`[3]`,
@@ -44,18 +59,18 @@ var pathTests = []struct {
 	},
 	{
 		`.a | .[].b == "apple"`,
-		append(make([]interface{}, 0), "a", "PIPE", "[]", "SHORT_PIPE", "b", "EQUALS", "apple (string)"),
-		append(make([]interface{}, 0), "a", "[]", "b", "SHORT_PIPE", "apple (string)", "EQUALS", "PIPE"),
+		append(make([]interface{}, 0), "a", "PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "b", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "apple (string)", "EQUALS", "PIPE"),
 	},
 	{
 		`(.a | .[].b) == "apple"`,
-		append(make([]interface{}, 0), "(", "a", "PIPE", "[]", "SHORT_PIPE", "b", ")", "EQUALS", "apple (string)"),
-		append(make([]interface{}, 0), "a", "[]", "b", "SHORT_PIPE", "PIPE", "apple (string)", "EQUALS"),
+		append(make([]interface{}, 0), "(", "a", "PIPE", "TRAVERSE_ARRAY", "[", "]", "SHORT_PIPE", "b", ")", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "PIPE", "apple (string)", "EQUALS"),
 	},
 	{
 		`.[] | select(. == "*at")`,
-		append(make([]interface{}, 0), "[]", "PIPE", "SELECT", "(", "SELF", "EQUALS", "*at (string)", ")"),
-		append(make([]interface{}, 0), "[]", "SELF", "*at (string)", "EQUALS", "SELECT", "PIPE"),
+		append(make([]interface{}, 0), "TRAVERSE_ARRAY", "[", "]", "PIPE", "SELECT", "(", "SELF", "EQUALS", "*at (string)", ")"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SELF", "*at (string)", "EQUALS", "SELECT", "PIPE"),
 	},
 	{
 		`[true]`,
@@ -89,8 +104,8 @@ var pathTests = []struct {
 	},
 	{
 		`{.a: .c, .b.[]: .f.g.[]}`,
-		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "SHORT_PIPE", "[]", "CREATE_MAP", "f", "SHORT_PIPE", "g", "SHORT_PIPE", "[]", "}"),
-		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "[]", "SHORT_PIPE", "f", "g", "SHORT_PIPE", "[]", "SHORT_PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "SHORT_PIPE"),
+		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "CREATE_MAP", "f", "SHORT_PIPE", "g", "SHORT_PIPE", "TRAVERSE_ARRAY", "[", "]", "}"),
+		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "f", "g", "SHORT_PIPE", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "SHORT_PIPE"),
 	},
 	{
 		`explode(.a.b)`,
@@ -122,7 +137,11 @@ var pathTests = []struct {
 		append(make([]interface{}, 0), "SELF", "ASSIGN_COMMENT", "str (string)"),
 		append(make([]interface{}, 0), "SELF", "str (string)", "ASSIGN_COMMENT"),
 	},
-
+	{
+		`. lineComment |= "str"`,
+		append(make([]interface{}, 0), "SELF", "ASSIGN_COMMENT", "str (string)"),
+		append(make([]interface{}, 0), "SELF", "str (string)", "ASSIGN_COMMENT"),
+	},
 	{
 		`.a.b tag="!!str"`,
 		append(make([]interface{}, 0), "a", "SHORT_PIPE", "b", "ASSIGN_TAG", "!!str (string)"),

pkg/yqlib/path_tokeniser.go

@@ -22,7 +22,7 @@ const (
 	CloseCollect
 	OpenCollectObject
 	CloseCollectObject
-	SplatOrEmptyCollect
+	TraverseArrayCollect
 )
 
 type Token struct {
@@ -49,8 +49,9 @@ func (t *Token) toString() string {
 		return "{"
 	} else if t.TokenType == CloseCollectObject {
 		return "}"
-	} else if t.TokenType == SplatOrEmptyCollect {
-		return "[]?"
+	} else if t.TokenType == TraverseArrayCollect {
+		return ".["
+
 	} else {
 		return "NFI"
 	}
@@ -91,6 +92,15 @@ func opAssignableToken(opType *OperationType, assignOpType *OperationType) lex.A
 	return opTokenWithPrefs(opType, assignOpType, nil)
 }
 
+func assignOpToken(updateAssign bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		log.Debug("assignOpToken %v", string(m.Bytes))
+		value := string(m.Bytes)
+		op := &Operation{OperationType: Assign, Value: Assign.Type, StringValue: value, UpdateAssign: updateAssign}
+		return &Token{TokenType: OperationToken, Operation: op}, nil
+	}
+}
+
 func opTokenWithPrefs(op *OperationType, assignOpType *OperationType, preferences interface{}) lex.Action {
 	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
 		log.Debug("opTokenWithPrefs %v", string(m.Bytes))
@@ -104,6 +114,21 @@ func opTokenWithPrefs(op *OperationType, assignOpType *OperationType, preference
 	}
 }
 
+func assignAllCommentsOp(updateAssign bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		log.Debug("assignAllCommentsOp %v", string(m.Bytes))
+		value := string(m.Bytes)
+		op := &Operation{
+			OperationType: AssignComment,
+			Value:         AssignComment.Type,
+			StringValue:   value,
+			UpdateAssign:  updateAssign,
+			Preferences:   &CommentOpPreferences{LineComment: true, HeadComment: true, FootComment: true},
+		}
+		return &Token{TokenType: OperationToken, Operation: op}, nil
+	}
+}
+
 func literalToken(pType TokenType, checkForPost bool) lex.Action {
 	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
 		return &Token{TokenType: pType, CheckForPostTraverse: checkForPost}, nil
@@ -114,23 +139,6 @@ func unwrap(value string) string {
 	return value[1 : len(value)-1]
 }
 
-func arrayIndextoken(precedingDot bool) lex.Action {
-	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
-		var numberString = string(m.Bytes)
-		startIndex := 1
-		if precedingDot {
-			startIndex = 2
-		}
-		numberString = numberString[startIndex : len(numberString)-1]
-		var number, errParsingInt = strconv.ParseInt(numberString, 10, 64) // nolint
-		if errParsingInt != nil {
-			return nil, errParsingInt
-		}
-		op := &Operation{OperationType: TraversePath, Value: number, StringValue: numberString}
-		return &Token{TokenType: OperationToken, Operation: op, CheckForPostTraverse: true}, nil
-	}
-}
-
 func numberValue() lex.Action {
 	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
 		var numberString = string(m.Bytes)
@@ -188,8 +196,12 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`\(`), literalToken(OpenBracket, false))
 	lexer.Add([]byte(`\)`), literalToken(CloseBracket, true))
 
-	lexer.Add([]byte(`\.\[\]`), pathToken(false))
-	lexer.Add([]byte(`\.\.`), opToken(RecursiveDescent))
+	lexer.Add([]byte(`\.\[`), literalToken(TraverseArrayCollect, false))
+	lexer.Add([]byte(`\.\.`), opTokenWithPrefs(RecursiveDescent, nil, &RecursiveDescentPreferences{RecurseArray: true,
+		TraversePreferences: &TraversePreferences{FollowAlias: false, IncludeMapKeys: false}}))
+
+	lexer.Add([]byte(`\.\.\.`), opTokenWithPrefs(RecursiveDescent, nil, &RecursiveDescentPreferences{RecurseArray: true,
+		TraversePreferences: &TraversePreferences{FollowAlias: false, IncludeMapKeys: true}}))
 
 	lexer.Add([]byte(`,`), opToken(Union))
 	lexer.Add([]byte(`:\s*`), opToken(CreateMap))
@@ -204,6 +216,7 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`\/\/`), opToken(Alternative))
 
 	lexer.Add([]byte(`documentIndex`), opToken(GetDocumentIndex))
+	lexer.Add([]byte(`di`), opToken(GetDocumentIndex))
 
 	lexer.Add([]byte(`style`), opAssignableToken(GetStyle, AssignStyle))
 
@@ -212,6 +225,7 @@ func initLexer() (*lex.Lexer, error) {
 	lexer.Add([]byte(`alias`), opAssignableToken(GetAlias, AssignAlias))
 	lexer.Add([]byte(`filename`), opToken(GetFilename))
 	lexer.Add([]byte(`fileIndex`), opToken(GetFileIndex))
+	lexer.Add([]byte(`fi`), opToken(GetFileIndex))
 	lexer.Add([]byte(`path`), opToken(GetPath))
 
 	lexer.Add([]byte(`lineComment`), opTokenWithPrefs(GetComment, AssignComment, &CommentOpPreferences{LineComment: true}))
@@ -220,18 +234,17 @@ func initLexer() (*lex.Lexer, error) {
 
 	lexer.Add([]byte(`footComment`), opTokenWithPrefs(GetComment, AssignComment, &CommentOpPreferences{FootComment: true}))
 
-	lexer.Add([]byte(`comments\s*=`), opTokenWithPrefs(AssignComment, nil, &CommentOpPreferences{LineComment: true, HeadComment: true, FootComment: true}))
+	lexer.Add([]byte(`comments\s*=`), assignAllCommentsOp(false))
+	lexer.Add([]byte(`comments\s*\|=`), assignAllCommentsOp(true))
 
 	lexer.Add([]byte(`collect`), opToken(Collect))
 
 	lexer.Add([]byte(`\s*==\s*`), opToken(Equals))
-	lexer.Add([]byte(`\s*=\s*`), opTokenWithPrefs(Assign, nil, &AssignOpPreferences{false}))
+	lexer.Add([]byte(`\s*=\s*`), assignOpToken(false))
 
 	lexer.Add([]byte(`del`), opToken(DeleteChild))
 
-	lexer.Add([]byte(`\s*\|=\s*`), opTokenWithPrefs(Assign, nil, &AssignOpPreferences{true}))
-
-	lexer.Add([]byte(`\.\[-?[0-9]+\]`), arrayIndextoken(true))
+	lexer.Add([]byte(`\s*\|=\s*`), assignOpToken(true))
 
 	lexer.Add([]byte("( |\t|\n|\r)+"), skip)
 
@@ -254,8 +267,6 @@ func initLexer() (*lex.Lexer, error) {
 
 	lexer.Add([]byte(`"[^"]*"`), stringValue(true))
 
-	lexer.Add([]byte(`\[\]`), literalToken(SplatOrEmptyCollect, true))
-
 	lexer.Add([]byte(`\[`), literalToken(OpenCollect, false))
 	lexer.Add([]byte(`\]`), literalToken(CloseCollect, true))
 	lexer.Add([]byte(`\{`), literalToken(OpenCollectObject, false))
@@ -324,30 +335,23 @@ func (p *pathTokeniser) Tokenise(path string) ([]*Token, error) {
 func (p *pathTokeniser) handleToken(tokens []*Token, index int, postProcessedTokens []*Token) (tokensAccum []*Token, skipNextToken bool) {
 	skipNextToken = false
 	token := tokens[index]
-	if token.TokenType == SplatOrEmptyCollect {
-		if index > 0 && tokens[index-1].TokenType == OperationToken &&
-			tokens[index-1].Operation.OperationType == TraversePath {
-			// must be a splat without a preceding dot , e.g. .a[]
-			// lets put a pipe in front of it, and convert it to a traverse "[]" token
-			pipeOp := &Operation{OperationType: ShortPipe, Value: "PIPE"}
 
-			postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: pipeOp})
+	if token.TokenType == TraverseArrayCollect {
+		//need to put a traverse array then a collect token
+		// do this by adding traverse then converting token to collect
 
-			traverseOp := &Operation{OperationType: TraversePath, Value: "[]", StringValue: "[]"}
-			token = &Token{TokenType: OperationToken, Operation: traverseOp, CheckForPostTraverse: true}
+		op := &Operation{OperationType: TraverseArray, StringValue: "TRAVERSE_ARRAY"}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+		token = &Token{TokenType: OpenCollect}
 
-		} else {
-			// gotta be a collect empty array, we need to split this into two tokens
-			// one OpenCollect, the other CloseCollect
-			postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OpenCollect})
-			token = &Token{TokenType: CloseCollect, CheckForPostTraverse: true}
-		}
 	}
 
 	if index != len(tokens)-1 && token.AssignOperation != nil &&
 		tokens[index+1].TokenType == OperationToken &&
 		tokens[index+1].Operation.OperationType == Assign {
 		token.Operation = token.AssignOperation
+		token.Operation.UpdateAssign = tokens[index+1].Operation.UpdateAssign
 		skipNextToken = true
 	}
 
@@ -359,5 +363,21 @@ func (p *pathTokeniser) handleToken(tokens []*Token, index int, postProcessedTok
 		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
 		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
 	}
+	if index != len(tokens)-1 && token.CheckForPostTraverse &&
+		tokens[index+1].TokenType == OpenCollect {
+
+		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+		op = &Operation{OperationType: TraverseArray}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+	}
+	if index != len(tokens)-1 && token.CheckForPostTraverse &&
+		tokens[index+1].TokenType == TraverseArrayCollect {
+
+		op := &Operation{OperationType: ShortPipe, Value: "PIPE"}
+		postProcessedTokens = append(postProcessedTokens, &Token{TokenType: OperationToken, Operation: op})
+
+	}
 	return postProcessedTokens, skipNextToken
 }

release_instructions.txt

@@ -1,9 +1,11 @@
 - increment version in version.go
 - increment version in snapcraft.yaml
+- increment version in github-action/Dockerfile
 - make sure local build passes
 - tag git with same version number
 - commit vX tag - this will trigger github actions
 - use github actions to publish docker and make github release
+- check github updated yq action in marketplace
 
 - snapcraft
   - will auto create a candidate, test it works then promote

scripts/check.sh

@@ -3,7 +3,12 @@
 set -o errexit
 set -o pipefail
 
+if command -v golangci-lint &> /dev/null
+then
+    golangci-lint run --timeout=5m
+else
   ./bin/golangci-lint run --timeout=5m
+fi
 
 # ./bin/golangci-lint \
 #   --tests \

scripts/publish-docker.sh

@@ -1,12 +0,0 @@
-#!/bin/bash
-set -ex
-VERSION="$(git describe --tags --abbrev=0)"
-docker build \
-  --target production \
-  --build-arg VERSION=${VERSION} \
-  -t mikefarah/yq:latest \
-  -t mikefarah/yq:${VERSION} \
-  -t mikefarah/yq:4 \
-  .
-
-trivy image mikefarah/yq:${VERSION}

scripts/release.sh

@@ -1,21 +0,0 @@
-#!/bin/bash
-set -ex
-GITHUB_TOKEN="${GITHUB_TOKEN:?missing required input \'GITHUB_TOKEN\'}"
-
-CURRENT="$(git describe --tags --abbrev=0)"
-PREVIOUS="$(git describe --tags --abbrev=0 --always "${CURRENT}"^)"
-OWNER="mikefarah"
-REPO="yq"
-
-release() {
-    github-release release \
-        --user "$OWNER" \
-        --draft \
-        --repo "$REPO" \
-        --tag "$CURRENT"
-}
-
-
-
-release
-

scripts/upload.sh

@@ -1,28 +0,0 @@
-#!/bin/bash
-set -ex
-GITHUB_TOKEN="${GITHUB_TOKEN:?missing required input \'GITHUB_TOKEN\'}"
-
-CURRENT="$(git describe --tags --abbrev=0)"
-PREVIOUS="$(git describe --tags --abbrev=0 --always "${CURRENT}"^)"
-OWNER="mikefarah"
-REPO="yq"
-
-upload() {
-    mkdir -p ./build-done
-    while IFS=  read -r -d $'\0'; do
-        file=$REPLY
-        BINARY=$(basename "${file}")
-        echo "--> ${BINARY}"
-        github-release upload \
-            --replace \
-            --user "$OWNER" \
-            --repo "$REPO" \
-            --tag "$CURRENT" \
-            --name "${BINARY}" \
-            --file "$file"
-        mv "$file" "./build-done/${BINARY}"
-    done < <(find ./build -mindepth 1 -maxdepth 1 -print0)
-}
-
-
-upload

snap/snapcraft.yaml

@@ -1,5 +1,5 @@
 name: yq
-version: '4.1.0'
+version: '4.2.1'
 summary: A lightweight and portable command-line YAML processor
 description: |
   The aim of the project is to be the jq or sed of yaml files.

yq_test.go

@@ -1,60 +0,0 @@
-package main
-
-// import (
-// 	"fmt"
-// 	"runtime"
-// 	"testing"
-
-// 	"github.com/mikefarah/yq/v2/pkg/marshal"
-// 	"github.com/mikefarah/yq/v2/test"
-// )
-
-// func TestMultilineString(t *testing.T) {
-// 	testString := `
-// 	abcd
-// 	efg`
-// 	formattedResult, _ := marshal.NewYamlConverter().YamlToString(testString, false)
-// 	test.AssertResult(t, testString, formattedResult)
-// }
-
-// func TestNewYaml(t *testing.T) {
-// 	result, _ := newYaml([]string{"b.c", "3"})
-// 	formattedResult := fmt.Sprintf("%v", result)
-// 	test.AssertResult(t,
-// 		"[{b [{c 3}]}]",
-// 		formattedResult)
-// }
-
-// func TestNewYamlArray(t *testing.T) {
-// 	result, _ := newYaml([]string{"[0].cat", "meow"})
-// 	formattedResult := fmt.Sprintf("%v", result)
-// 	test.AssertResult(t,
-// 		"[[{cat meow}]]",
-// 		formattedResult)
-// }
-
-// func TestNewYaml_WithScript(t *testing.T) {
-// 	writeScript = "examples/instruction_sample.yaml"
-// 	expectedResult := `b:
-//   c: cat
-//   e:
-//   - name: Mike Farah`
-// 	result, _ := newYaml([]string{""})
-// 	actualResult, _ := marshal.NewYamlConverter().YamlToString(result, true)
-// 	test.AssertResult(t, expectedResult, actualResult)
-// }
-
-// func TestNewYaml_WithUnknownScript(t *testing.T) {
-// 	writeScript = "fake-unknown"
-// 	_, err := newYaml([]string{""})
-// 	if err == nil {
-// 		t.Error("Expected error 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, err.Error())
-// }