Added gofmt to format command

Fixes #716 #715

.dockerignore

@@ -1 +1 @@
-bin
+bin/*

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: mikefarah

.github/ISSUE_TEMPLATE/bug_report_v3.md

@@ -1,8 +1,8 @@
 ---
-name: Bug report
+name: Bug report - V3
 about: Create a report to help us improve
 title: ''
-labels: bug
+labels: bug, v3
 assignees: ''
 
 ---
@@ -10,11 +10,14 @@ assignees: ''
 **Describe the bug**
 A clear and concise description of what the bug is.
 
-version of yq: 
-operating system:
+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/...
 
 **Input Yaml**
-Concise yaml document(s) (as simple as possible to show the bug)
+Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
 data1.yml:
 ```yaml
 this: should really work

.github/ISSUE_TEMPLATE/bug_report_v4.md

@@ -0,0 +1,51 @@
+---
+name: Bug report - V4
+about: Create a report to help us improve
+title: ''
+labels: bug, v4
+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/...
+
+**Input Yaml**
+Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
+data1.yml:
+```yaml
+this: should really work
+```
+
+data2.yml:
+```yaml
+but: it strangely didn't
+```
+
+**Command**
+The command you ran:
+```
+yq eval-all 'select(fileIndex==0) | .a.b.c' data1.yml data2.yml
+```
+
+**Actual behavior**
+
+```yaml
+cat: meow
+```
+
+**Expected behavior**
+
+```yaml
+this: should really work
+but: it strangely didn't
+```
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,17 +1,23 @@
 ---
-name: Feature request
+name: Feature request - V4
 about: Suggest an idea for this project
 title: ''
-labels: enhancement
+labels: enhancement, v4
 assignees: ''
 
 ---
 
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+**Please describe your feature request.**
+A clear and concise description of what the request is and what it would solve. 
+Eg. I wish I could use yq to [...]
+
+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:
+(please keep to around 10 lines )
 
 ```yaml
 country: Australia
@@ -20,7 +26,7 @@ country: Australia
 And we run a command:
 
 ```bash
-yq predictWeather data1.yml
+yq eval 'predictWeatherOf(.country)'
 ```
 
 it could output

.github/workflows/go.yml

@@ -28,7 +28,4 @@ jobs:
       run: |
         export PATH=${PATH}:`go env GOPATH`/bin
         scripts/devtools.sh
-    - name: Build
-      run: |
-        export PATH=${PATH}:`go env GOPATH`/bin
         make local build

.github/workflows/release.yml

@@ -0,0 +1,70 @@
+name: Release YQ
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  publishGitRelease:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
+        with:
+          go-version: '^1.15'
+      - name: Cross compile
+        run: |
+          sudo apt-get install rhash -y
+          go get github.com/mitchellh/gox
+          ./scripts/xcompile.sh
+
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1.0.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: true
+          prerelease: false
+
+      - uses: shogo82148/actions-upload-release-asset@v1
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: build/*
+
+  publishDocker:
+    environment: dockerhub
+    env:
+      IMAGE_NAME: mikefarah/yq
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+        with:
+          platforms: all
+  
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v1
+        with:
+          version: latest
+
+      - name: Available platforms
+        run: echo ${{ steps.buildx.outputs.platforms }} && docker version
+ 
+      - name: Build and push image
+        run: |
+          IMAGE_V_VERSION="$(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}"
+          echo ${{ secrets.DOCKER_PASSWORD }} | docker login -u ${{ secrets.DOCKER_USERNAME }} --password-stdin
+          docker buildx build --platform "${PLATFORMS}" -t "${IMAGE_NAME}:${IMAGE_VERSION}"  -t "${IMAGE_NAME}:latest" -t "${IMAGE_NAME}:4" \
+            --push .
+    

Dockerfile

@@ -12,7 +12,7 @@ RUN CGO_ENABLED=0 make local build
 
 # Choose alpine as a base image to make this useful for CI, as many
 # CI tools expect an interactive shell inside the container
-FROM alpine:3.12 as production
+FROM alpine:3.12.3 as production
 
 COPY --from=builder /go/src/mikefarah/yq/yq /usr/bin/yq
 RUN chmod +x /usr/bin/yq

Dockerfile.dev

@@ -4,27 +4,7 @@ COPY scripts/devtools.sh /opt/devtools.sh
 
 RUN set -e -x \
     && /opt/devtools.sh
-
-# install mkdocs
-RUN set -ex \
-    && buildDeps=' \
-        build-essential \
-        python3-dev \
-    ' \
-    && apt-get update && apt-get install -y --no-install-recommends \
-        $buildDeps \
-        python3 \
-        python3-setuptools \
-        python3-wheel \
-        python3-pip \
-    && pip3 install --upgrade \
-        pip \
-        'Markdown>=2.6.9' \
-        'mkdocs>=0.16.3' \
-        'mkdocs-material>=1.10.1' \
-        'markdown-include>=0.5.1' \
-    && apt-get purge -y --auto-remove $buildDeps \
-    && rm -rf /var/lib/apt/lists/*
+ENV PATH=/go/bin:$PATH
 
 ENV CGO_ENABLED 0
 ENV GOPATH /go:/yq

Makefile

@@ -17,6 +17,7 @@ help:
 	@echo '    make vendor          Install dependencies to vendor directory.'
 	@echo '    make format          Run code formatter.'
 	@echo '    make check           Run static code analysis (lint).'
+	@echo '    make secure          Run gosec.'
 	@echo '    make test            Run tests on project.'
 	@echo '    make cover           Run tests and capture code coverage metrics on project.'
 	@echo '    make clean           Clean the directory tree of produced artifacts.'
@@ -84,6 +85,10 @@ format: vendor
 check: format
 	${DOCKRUN} bash ./scripts/check.sh
 
+.PHONY: secure
+secure: 
+	${DOCKRUN} bash ./scripts/secure.sh
+
 .PHONY: test
 test: check
 	${DOCKRUN} bash ./scripts/test.sh
@@ -96,11 +101,6 @@ cover: check
 	@find cover -type d -exec chmod 755 {} \; || :
 	@find cover -type f -exec chmod 644 {} \; || :
 
-.PHONY: build-docs
-build-docs: prepare mkdocs.yml mkdocs/*
-	${DOCKRUN} mkdocs build
-	@find docs -type d -exec chmod 755 {} \; || :
-	@find docs -type f -exec chmod 644 {} \; || :
 
 .PHONY: release
 release: xcompile

README.md

@@ -3,91 +3,137 @@
 ![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:
 
 ```
-sudo cat /etc/myfile | yq r - a.path
+sudo cat /etc/myfile | yq e '.a.path' - 
 ```
 
 And to write to a root file you can either use [sponge](https://linux.die.net/man/1/sponge):
 ```
-sudo cat /etc/myfile | yq w - a.path value | sudo sponge /etc/myfile
+sudo cat /etc/myfile | yq e '.a.path = "value"' - | sudo sponge /etc/myfile
 ```
 or write to a temporary file:
 ```
-sudo cat /etc/myfile | yq w - a.path value | sudo tee /etc/myfile.tmp
+sudo cat /etc/myfile | yq e '.a.path = "value"' | sudo tee /etc/myfile.tmp
 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=3.4.0 and BINARY=yq_linux_amd64
-
-
 ### Run with Docker
 
 #### Oneshot use:
 
 ```bash
-docker run --rm -v "${PWD}":/workdir mikefarah/yq yq [flags] <command> FILE...
+docker run --rm -v "${PWD}":/workdir mikefarah/yq <command> [flags] [expression ]FILE...
 ```
 
 #### Run commands interactively:
 
 ```bash
-docker run --rm -it -v "${PWD}":/workdir mikefarah/yq sh
+docker run --rm -it -v "${PWD}":/workdir --entrypoint sh mikefarah/yq
 ```
 
 It can be useful to have a bash function to avoid typing the whole docker command:
 
 ```bash
 yq() {
-  docker run --rm -i -v "${PWD}":/workdir mikefarah/yq yq "$@"
+  docker run --rm -i -v "${PWD}":/workdir mikefarah/yq "$@"
 }
 ```
 
 ### Go Get:
 ```
-GO111MODULE=on go get github.com/mikefarah/yq/v3
+GO111MODULE=on go get github.com/mikefarah/yq/v4
 ```
 
 ## Community Supported Installation methods
 As these are supported by the community :heart: - however, they may be out of date with the officially supported releases.
 
+# Webi
+
+```
+webi yq
+```
+
+See [webi](https://webinstall.dev/)
+Supported by @adithyasunil26 (https://github.com/webinstall/webi-installers/tree/master/yq)
 
 ### Windows:
+[![Chocolatey](https://img.shields.io/chocolatey/v/yq.svg)](https://chocolatey.org/packages/yq)
+[![Chocolatey](https://img.shields.io/chocolatey/dt/yq.svg)](https://chocolatey.org/packages/yq)
 ```
 choco install yq
 ```
 Supported by @chillum (https://chocolatey.org/packages/yq)
 
+### Mac:
+Using [MacPorts](https://www.macports.org/)
+```
+sudo port selfupdate
+sudo port install yq
+```
+Supported by @herbygillot (https://ports.macports.org/maintainer/github/herbygillot)
+
 ### Alpine Linux
 - Enable edge/community repo by adding ```$MIRROR/alpine/edge/community``` to ```/etc/apk/repositories```
 - Update database index with ```apk update```
@@ -107,23 +153,21 @@ sudo apt install yq -y
 Supported by @rmescandon (https://launchpad.net/~rmescandon/+archive/ubuntu/yq)
 
 ## Features
+- [Detailed documentation with many examples](https://mikefarah.gitbook.io/yq/)
 - Written in portable go, so you can download a lovely dependency free binary
-- [Colorize the output](https://mikefarah.gitbook.io/yq/usage/output-format#colorize-output)
-- [Deep read a yaml file with a given path expression](https://mikefarah.gitbook.io/yq/commands/read#basic)
-- [List matching paths of a given path expression](https://mikefarah.gitbook.io/yq/commands/read#path-only)
-- [Return the lengths of arrays/object/scalars](https://mikefarah.gitbook.io/yq/commands/read#printing-length-of-the-results)
-- Update a yaml file given a [path expression](https://mikefarah.gitbook.io/yq/commands/write-update#basic) or [script file](https://mikefarah.gitbook.io/yq/commands/write-update#basic)
-- Update creates any missing entries in the path on the fly
-- Deeply [compare](https://mikefarah.gitbook.io/yq/commands/compare) yaml files
-- Keeps yaml formatting and comments when updating
-- [Validate a yaml file](https://mikefarah.gitbook.io/yq/commands/validate)
-- Create a yaml file given a [deep path and value](https://mikefarah.gitbook.io/yq/commands/create#creating-a-simple-yaml-file) or a [script file](https://mikefarah.gitbook.io/yq/commands/create#creating-using-a-create-script)
-- [Prefix a path to a yaml file](https://mikefarah.gitbook.io/yq/commands/prefix)
-- [Convert to/from json to yaml](https://mikefarah.gitbook.io/yq/usage/convert)
-- [Pipe data in by using '-'](https://mikefarah.gitbook.io/yq/commands/read#from-stdin)
-- [Merge](https://mikefarah.gitbook.io/yq/commands/merge) multiple yaml files with various options for [overriding](https://mikefarah.gitbook.io/yq/commands/merge#overwrite-values) and [appending](https://mikefarah.gitbook.io/yq/commands/merge#append-values-with-arrays)
-- Supports multiple documents in a single yaml file for [reading](https://mikefarah.gitbook.io/yq/commands/read#multiple-documents), [writing](https://mikefarah.gitbook.io/yq/commands/write-update#multiple-documents) and [merging](https://mikefarah.gitbook.io/yq/commands/merge#multiple-documents)
-- General shell completion scripts (bash/zsh/fish/powershell) (https://mikefarah.gitbook.io/yq/commands/shell-completion)
+- Uses similar syntax as `jq` but works with YAML and JSON files
+- Fully supports multi document yaml files
+- Colorized yaml output
+- [Deeply traverse yaml](https://mikefarah.gitbook.io/yq/operators/traverse-read)
+- [Sort yaml by keys](https://mikefarah.gitbook.io/yq/operators/sort-keys)
+- Manipulate yaml [comments](https://mikefarah.gitbook.io/yq/operators/comment-operators), [styling](https://mikefarah.gitbook.io/yq/operators/style), [tags](https://mikefarah.gitbook.io/yq/operators/tag) and [anchors and aliases](https://mikefarah.gitbook.io/yq/operators/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/operators/select#select-and-update-matching-values-in-map)
+- Keeps yaml formatting and comments when updating (though there are issues with whitespace)
+- [Convert to/from json to yaml](https://mikefarah.gitbook.io/yq/v/v4.x/usage/convert)
+- [Pipe data in by using '-'](https://mikefarah.gitbook.io/yq/v/v4.x/commands/evaluate)
+- [General shell completion scripts (bash/zsh/fish/powershell)](https://mikefarah.gitbook.io/yq/v/v4.x/commands/shell-completion)
+- [Reduce](https://mikefarah.gitbook.io/yq/operators/reduce) to merge multiple files or sum an array or other fancy things.
 
 ## [Usage](https://mikefarah.gitbook.io/yq/)
 
@@ -135,32 +179,33 @@ Usage:
   yq [command]
 
 Available Commands:
-  compare          yq x [--prettyPrint/-P] dataA.yaml dataB.yaml 'b.e(name==fr*).value'
-  delete           yq d [--inplace/-i] [--doc/-d index] sample.yaml 'b.e(name==fred)'
+  eval             Apply expression to each document in each yaml file given in sequence
+  eval-all         Loads _all_ yaml documents of _all_ yaml files and runs expression once
   help             Help about any command
-  merge            yq m [--inplace/-i] [--doc/-d index] [--overwrite/-x] [--append/-a] sample.yaml sample2.yaml
-  new              yq n [--script/-s script_file] a.b.c newValue
-  prefix           yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c
-  read             yq r [--printMode/-p pv] sample.yaml 'b.e(name==fr*).value'
-  shell-completion Generates shell completion scripts
-  validate         yq v sample.yaml
-  write            yq w [--inplace/-i] [--script/-s script_file] [--doc/-d index] sample.yaml 'b.e(name==fr*).value' newValue
+  shell-completion Generate completion script
 
 Flags:
-  -C, --colors        print with colors
+  -C, --colors        force print with colors
+  -e, --exit-status   set exit status if there are no matches or null or false is returned
   -h, --help          help for yq
   -I, --indent int    sets indent level for output (default 2)
-  -P, --prettyPrint   pretty print
-  -j, --tojson        output as json. By default it prints a json document in one line, use the prettyPrint flag to print a formatted doc.
+  -i, --inplace       update the yaml file inplace of first yaml file given.
+  -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
 
 Use "yq [command] --help" for more information about a command.
 ```
 
-## Upgrade from V2
-If you've been using v2 and want/need to upgrade, checkout the [upgrade guide](https://mikefarah.gitbook.io/yq/upgrading-from-v2).
+Simple Example:
+
+```bash
+yq e '.a.b | length' f1.yml f2.yml 
+```
 
 ## Known Issues / Missing Features
 - `yq` attempts to preserve comment positions and whitespace as much as possible, but it does not handle all scenarios (see https://github.com/go-yaml/yaml/tree/v3 for details)
-- You cannot (yet) select multiple paths/keys from the yaml to be printed out (https://github.com/mikefarah/yq/issues/287)

cmd/constant.go

@@ -2,10 +2,10 @@ package cmd
 
 var unwrapScalar = true
 
-// var writeInplace = false
+var writeInplace = false
 var outputToJSON = false
 
-// var exitStatus = false
+var exitStatus = false
 var forceColor = false
 var forceNoColor = false
 var colorsEnabled = false
@@ -14,5 +14,6 @@ var noDocSeparators = false
 var nullInput = false
 var verbose = false
 var version = false
+var prettyPrint = false
 
-// var log = logging.MustGetLogger("yq")
+var completedSuccessfully = false

cmd/evaluate_all_command.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"errors"
+	"fmt"
 	"os"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
@@ -13,9 +15,11 @@ func createEvaluateAllCommand() *cobra.Command {
 		Aliases: []string{"ea"},
 		Short:   "Loads _all_ yaml documents of _all_ yaml files and runs expression once",
 		Example: `
-yq es '.a.b | length' file1.yml file2.yml
-yq es < sample.yaml
-yq es -n '{"a": "b"}'
+# merges f2.yml into f1.yml (inplace)
+yq eval-all --inplace 'select(fileIndex == 0) * select(fileIndex == 1)' f1.yml f2.yml		
+
+# use '-' as a filename to read from STDIN
+cat file2.yml | yq ea '.a.b' file1.yml - file3.yml
 `,
 		Long: "Evaluate All:\nUseful when you need to run an expression across several yaml documents or files. Consumes more memory than eval",
 		RunE: evaluateAll,
@@ -23,6 +27,7 @@ yq es -n '{"a": "b"}'
 	return cmdEvalAll
 }
 func evaluateAll(cmd *cobra.Command, args []string) error {
+	cmd.SilenceUsage = true
 	// 0 args, read std in
 	// 1 arg, null input, process expression
 	// 1 arg, read file in sequence
@@ -39,26 +44,61 @@ func evaluateAll(cmd *cobra.Command, args []string) error {
 	if forceColor || (!forceNoColor && (fileInfo.Mode()&os.ModeCharDevice) != 0) {
 		colorsEnabled = true
 	}
+
+	firstFileIndex := -1
+	if !nullInput && len(args) == 1 {
+		firstFileIndex = 0
+	} else if len(args) > 1 {
+		firstFileIndex = 1
+	}
+
+	if writeInplace && (firstFileIndex == -1) {
+		return fmt.Errorf("Write inplace flag only applicable when giving an expression and at least one file")
+	}
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[firstFileIndex])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() { writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully) }()
+	}
+
+	if nullInput && len(args) > 1 {
+		return errors.New("Cannot pass files in when using null-input flag")
+	}
+
 	printer := yqlib.NewPrinter(out, outputToJSON, unwrapScalar, colorsEnabled, indent, !noDocSeparators)
+
 	allAtOnceEvaluator := yqlib.NewAllAtOnceEvaluator()
 	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 = allAtOnceEvaluator.EvaluateFiles(args[0], []string{}, 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
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
 	}
 
-	cmd.SilenceUsage = true
 	return err
 }

cmd/evalute_sequence_command.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"errors"
+	"fmt"
 	"os"
 
 	"github.com/mikefarah/yq/v4/pkg/yqlib"
@@ -13,16 +15,39 @@ func createEvaluateSequenceCommand() *cobra.Command {
 		Aliases: []string{"e"},
 		Short:   "Apply expression to each document in each yaml file given in sequence",
 		Example: `
-yq es '.a.b | length' file1.yml file2.yml
-yq es < sample.yaml
-yq es -n '{"a": "b"}'
+# runs the expression against each file, in series
+yq e '.a.b | length' f1.yml f2.yml 
+
+# prints out the file
+yq e sample.yaml 
+
+# use '-' as a filename to read from STDIN
+cat file2.yml | yq e '.a.b' file1.yml - file3.yml
+
+# prints a new yaml document
+yq e -n '.a.b.c = "cat"' 
+
+
+# updates file.yaml directly
+yq e '.a.b = "cool"' -i file.yaml 
 `,
 		Long: "Evaluate Sequence:\nIterate over each yaml document, apply the expression and print the results, in sequence.",
 		RunE: evaluateSequence,
 	}
 	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
 	// 1 arg, null input, process expression
 	// 1 arg, read file in sequence
@@ -39,29 +64,61 @@ func evaluateSequence(cmd *cobra.Command, args []string) error {
 	if forceColor || (!forceNoColor && (fileInfo.Mode()&os.ModeCharDevice) != 0) {
 		colorsEnabled = true
 	}
+
+	firstFileIndex := -1
+	if !nullInput && len(args) == 1 {
+		firstFileIndex = 0
+	} else if len(args) > 1 {
+		firstFileIndex = 1
+	}
+
+	if writeInplace && (firstFileIndex == -1) {
+		return fmt.Errorf("Write inplace flag only applicable when giving an expression and at least one file")
+	}
+
+	if writeInplace {
+		// only use colors if its forced
+		colorsEnabled = forceColor
+		writeInPlaceHandler := yqlib.NewWriteInPlaceHandler(args[firstFileIndex])
+		out, err = writeInPlaceHandler.CreateTempFile()
+		if err != nil {
+			return err
+		}
+		// need to indirectly call the function so  that completedSuccessfully is
+		// passed when we finish execution as opposed to now
+		defer func() { writeInPlaceHandler.FinishWriteInPlace(completedSuccessfully) }()
+	}
+
 	printer := yqlib.NewPrinter(out, outputToJSON, unwrapScalar, colorsEnabled, indent, !noDocSeparators)
 
 	streamEvaluator := yqlib.NewStreamEvaluator()
-	allAtOnceEvaluator := yqlib.NewAllAtOnceEvaluator()
+
+	if nullInput && len(args) > 1 {
+		return errors.New("Cannot pass files in when using null-input flag")
+	}
 
 	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 = allAtOnceEvaluator.EvaluateFiles(args[0], []string{}, 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)
+		err = streamEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer)
+	}
+	completedSuccessfully = err == nil
+
+	if err == nil && exitStatus && !printer.PrintedAnything() {
+		return errors.New("no matches found")
 	}
 
-	cmd.SilenceUsage = true
 	return err
 }

cmd/root.go

@@ -46,6 +46,10 @@ func New() *cobra.Command {
 
 	rootCmd.PersistentFlags().IntVarP(&indent, "indent", "I", 2, "sets indent level for output")
 	rootCmd.Flags().BoolVarP(&version, "version", "V", false, "Print version information and quit")
+	rootCmd.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace of first yaml file given.")
+	rootCmd.PersistentFlags().BoolVarP(&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")
 	rootCmd.PersistentFlags().BoolVarP(&forceNoColor, "no-colors", "M", false, "force print with no colors")

cmd/version.go

@@ -11,7 +11,7 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "4.0.0-alpha2"
+	Version = "4.9.3"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
 	// then it means that it is a final release. Otherwise, this is a pre-release

cmd/write.go

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

cmd/write_test.go

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

examples/data1.yaml

@@ -1,4 +1,6 @@
-a: simple # just the best
-b: [1, 2]
-c:
-  test: 1
+a:
+  key1: "value1"
+  key2: 2.6
+  ab:
+    key1: 6
+    key2: "h"

github-action/Dockerfile

@@ -1,4 +1,4 @@
-FROM mikefarah/yq:3
+FROM mikefarah/yq:4.9.3
 
 COPY entrypoint.sh /entrypoint.sh
 

go.mod

@@ -1,19 +1,16 @@
 module github.com/mikefarah/yq/v4
 
 require (
-	github.com/elliotchance/orderedmap v1.3.0
-	github.com/fatih/color v1.9.0
-	github.com/goccy/go-yaml v1.8.1
-	github.com/jinzhu/copier v0.0.0-20190924061706-b57f9002281a
-	github.com/mattn/go-colorable v0.1.7 // indirect
-	github.com/spf13/cobra v1.0.0
-	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/elliotchance/orderedmap v1.4.0
+	github.com/fatih/color v1.10.0
+	github.com/goccy/go-yaml v1.8.9
+	github.com/jinzhu/copier v0.2.8
+	github.com/spf13/cobra v1.1.3
 	github.com/timtadh/data-structures v0.5.3 // indirect
 	github.com/timtadh/lexmachine v0.2.2
-	golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f // indirect
-	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
+	golang.org/x/sys v0.0.0-20210317225723-c4fcb01b228e // indirect
 	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
-	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 )
 
 go 1.15

go.sum

@@ -1,16 +1,33 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+cloud.google.com/go v0.38.0/go.mod h1:990N+gfupTy94rShfmMCWGDn0LpTmnzTp2qbd1dvSRU=
+cloud.google.com/go v0.44.1/go.mod h1:iSa0KzasP4Uvy3f1mN/7PiObzGgflwredwwASm/v6AU=
+cloud.google.com/go v0.44.2/go.mod h1:60680Gw3Yr4ikxnPRS/oxxkBccT6SA1yMk63TGekxKY=
+cloud.google.com/go v0.45.1/go.mod h1:RpBamKRgapWJb87xiFSdk4g1CME7QZg3uwTez+TSTjc=
+cloud.google.com/go v0.46.3/go.mod h1:a6bKKbmY7er1mI7TEI4lsAkts/mkhTSZK8w33B4RAg0=
+cloud.google.com/go/bigquery v1.0.1/go.mod h1:i/xbL2UlR5RvWAURpBYZTtm/cXjCha9lbfbpx4poX+o=
+cloud.google.com/go/datastore v1.0.0/go.mod h1:LXYbyblFSglQ5pkeyhO+Qmw7ukd3C+pD7TKLgZqpHYE=
+cloud.google.com/go/firestore v1.1.0/go.mod h1:ulACoGHTpvq5r8rxGJ4ddJZBZqakUQqClKRT5SZwBmk=
+cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
+cloud.google.com/go/storage v1.0.0/go.mod h1:IhtSnM/ZTZV8YYJWCY8RULGVqBDmpoyjwiyrjsg+URw=
+dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
-github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
+github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hCbHZ8TKRvWD2dDTCfh9M9ya+I9JpbB7O8o=
+github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
+github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
+github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
+github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJmJgSg28kpZDP6UIiPt0e0Oz0kqKNGyRaWEPv84=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
-github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
-github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
+github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
@@ -19,40 +36,77 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
-github.com/elliotchance/orderedmap v1.3.0 h1:k6m77/d0zCXTjsk12nX40TkEBkSICq8T4s6R6bpCqU0=
-github.com/elliotchance/orderedmap v1.3.0/go.mod h1:8hdSl6jmveQw8ScByd3AaNHNk51RhbTazdqtTty+NFw=
+github.com/elliotchance/orderedmap v1.4.0 h1:wZtfeEONCbx6in1CZyE6bELEt/vFayMvsxqI5SgsR+A=
+github.com/elliotchance/orderedmap v1.4.0/go.mod h1:wsDwEaX5jEoyhbs7x93zk2H/qv0zwuhg4inXhDkYqys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
-github.com/fatih/color v1.9.0 h1:8xPHl4/q1VyqGIPif1F+1V3Y3lSmrq01EabUW3CoW5s=
-github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
+github.com/fatih/color v1.10.0 h1:s36xzo75JdqLaaWoiEHk767eHiwo0598uUxyfiPkDsg=
+github.com/fatih/color v1.10.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGEBuJM=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
+github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTMfnGwq/HNwmWNS8=
 github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
+github.com/go-playground/validator/v10 v10.4.1/go.mod h1:nlOn6nFhuKACm19sB/8EGNn9GlaMV7XkbRSipzJ0Ii4=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
-github.com/goccy/go-yaml v1.8.1 h1:JuZRFlqLM5cWF6A+waL8AKVuCcqvKOuhJtUQI+L3ez0=
-github.com/goccy/go-yaml v1.8.1/go.mod h1:wS4gNoLalDSJxo/SpngzPQ2BN4uuZVLCmbM4S3vd4+Y=
+github.com/goccy/go-yaml v1.8.9 h1:4AEXg2qx+/w29jXnXpMY6mTckmYu1TMoHteKuMf0HFg=
+github.com/goccy/go-yaml v1.8.9/go.mod h1:U/jl18uSupI5rdI2jmuCswEA2htH9eXfferR3KfscvA=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
+github.com/golang/mock v1.2.0/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
+github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFUx0Y=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
-github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
+github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
+github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
+github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
+github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
+github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
+github.com/hashicorp/consul/api v1.1.0/go.mod h1:VmuI/Lkw1nC05EYQWNKwWGbkg+FbDBtguAZLlVdkD9Q=
+github.com/hashicorp/consul/sdk v0.1.1/go.mod h1:VKf9jXwCTEY1QZP2MOLRhb5i/I/ssyNV1vwHyQBF0x8=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
+github.com/hashicorp/go-immutable-radix v1.0.0/go.mod h1:0y9vanUI8NX6FsYoO3zeMjhV/C5i9g4Q3DwcSNZ4P60=
+github.com/hashicorp/go-msgpack v0.5.3/go.mod h1:ahLV/dePpqEmjfWmKiqvPkv/twdG7iPBM1vqhUKIvfM=
+github.com/hashicorp/go-multierror v1.0.0/go.mod h1:dHtQlpGsu+cZNNAkkCN/P3hoUDHhCYQXV3UM06sGGrk=
+github.com/hashicorp/go-rootcerts v1.0.0/go.mod h1:K6zTfqpRlCUIjkwsN4Z+hiSfzSTQa6eBIzfwKfwNnHU=
+github.com/hashicorp/go-sockaddr v1.0.0/go.mod h1:7Xibr9yA9JjQq1JpNB2Vw7kxv8xerXegt+ozgdvDeDU=
+github.com/hashicorp/go-syslog v1.0.0/go.mod h1:qPfqrKkXGihmCqbJM2mZgkZGvKG1dFdvsLplgctolz4=
+github.com/hashicorp/go-uuid v1.0.0/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
+github.com/hashicorp/go-uuid v1.0.1/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
+github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
+github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
+github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=
+github.com/hashicorp/mdns v1.0.0/go.mod h1:tL+uN++7HEJ6SQLQ2/p+z2pH24WQKWjBPkE0mNTz8vQ=
+github.com/hashicorp/memberlist v0.1.3/go.mod h1:ajVTdAv/9Im8oMAAj5G31PhhMCZJV2pPBoIllUwCN7I=
+github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
-github.com/jinzhu/copier v0.0.0-20190924061706-b57f9002281a h1:zPPuIq2jAWWPTrGt70eK/BSch+gFAGrNzecsoENgu2o=
-github.com/jinzhu/copier v0.0.0-20190924061706-b57f9002281a/go.mod h1:yL958EeXv8Ylng6IfnvG4oflryUi3vgA3xPs9hmII1s=
+github.com/jinzhu/copier v0.2.8 h1:N8MbL5niMwE3P4dOwurJixz5rMkKfujmMRFmAanSzWE=
+github.com/jinzhu/copier v0.2.8/go.mod h1:24xnZezI2Yqac9J61UC6/dG/k76ttpq0DdJI3QmUvro=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
+github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
+github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
+github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
@@ -64,26 +118,34 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
-github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
-github.com/mattn/go-colorable v0.1.4 h1:snbPLB8fVfU9iwbbo30TPtbLRzwWu6aJS6Xh4eaaviA=
-github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
-github.com/mattn/go-colorable v0.1.7 h1:bQGKb3vps/j0E9GfJQ03JyhRuxsvdAanXlT9BTw3mdw=
-github.com/mattn/go-colorable v0.1.7/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
-github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
-github.com/mattn/go-isatty v0.0.10/go.mod h1:qgIWMr58cqv1PHHyhnkY9lrL7etaEgOFcMEpPG5Rm84=
-github.com/mattn/go-isatty v0.0.11 h1:FxPOTFNqGkuDUGi3H/qkUbQO4ZiBa2brKq5r0l8TGeM=
-github.com/mattn/go-isatty v0.0.11/go.mod h1:PhnuNfih5lzO57/f3n+odYbM4JtupLOxQOAqxQCu2WE=
+github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
+github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
+github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
+github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
+github.com/mitchellh/go-homedir v1.0.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/go-testing-interface v1.0.0/go.mod h1:kRemZodwjscx+RGhAo8eIhFbs2+BFgRtFPeD/KE+zxI=
+github.com/mitchellh/gox v0.4.0/go.mod h1:Sd9lOJ0+aimLBi73mGofS1ycjY8lL3uZM3JPS42BGNg=
+github.com/mitchellh/iochan v1.0.0/go.mod h1:JwYml1nuB7xOzsp52dPpHFffvOCDupsG0QubkSMEySY=
+github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
+github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
@@ -94,95 +156,173 @@ github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
+github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
+github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
+github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
+github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
-github.com/spf13/cobra v1.0.0 h1:6m/oheQuQ13N9ks4hubMG6BnvwOeaJrqSPLahSnczz8=
-github.com/spf13/cobra v1.0.0/go.mod h1:/6GTrnGXV9HjY+aR4k0oJ5tcvakLuG6EuKReYlHNrgE=
+github.com/spf13/cobra v1.1.3 h1:xghbfqPkxzxP3C/f3n5DdpAbdKLj4ZE4BWQI362l53M=
+github.com/spf13/cobra v1.1.3/go.mod h1:pGADOWyqRD/YMrPZigI/zbliZ2wVD/23d+is3pSWzOo=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
-github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-github.com/spf13/viper v1.4.0/go.mod h1:PTJ7Z/lr49W6bUbkmS1V3by4uWynFiR9p7+dSq/yZzE=
+github.com/spf13/viper v1.7.0/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
-github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/timtadh/data-structures v0.5.3 h1:F2tEjoG9qWIyUjbvXVgJqEOGJPMIiYn7U5W5mE+i/vQ=
 github.com/timtadh/data-structures v0.5.3/go.mod h1:9R4XODhJ8JdWFEI8P/HJKqxuJctfBQw6fDibMQny2oU=
 github.com/timtadh/lexmachine v0.2.2 h1:g55RnjdYazm5wnKv59pwFcBJHOyvTPfDEoz21s4PHmY=
 github.com/timtadh/lexmachine v0.2.2/go.mod h1:GBJvD5OAfRn/gnp92zb9KTgHLB7akKyxmVivoYCcjQI=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
-github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
-github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
+go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
+go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
+golang.org/x/exp v0.0.0-20190829153037-c13cbed26979/go.mod h1:86+5VVa7VpoJ4kLfm080zCjGlMRFzhUhsZKEZO7MGek=
+golang.org/x/exp v0.0.0-20191030013958-a1ab85dbe136/go.mod h1:JXzH8nQsPlswgeRAPE3MuO9GYsAcnJvJ4vnMwN/5qkY=
+golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
+golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
+golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/lint v0.0.0-20190409202823-959b441ac422/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/lint v0.0.0-20190909230951-414d861bb4ac/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
+golang.org/x/mobile v0.0.0-20190719004257-d2bd2a29d028/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
+golang.org/x/mod v0.0.0-20190513183733-4bf6d317e70e/go.mod h1:mXi4GBBbnImb6dmsKGUJ2LatrhH/nqhxcFungHvyanc=
+golang.org/x/mod v0.1.0/go.mod h1:0QHyrYULN0/3qlju5TqG8bIK38QM8yzMo5ekMj3DlcY=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181023162649-9b4f9f5ad519/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181201002055-351d144fa1fc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190501004415-9ce7a6920f09/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190503192946-f4e77d36d62c/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
+golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
+golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20181026203630-95b1ffbd15a5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193GlqGZbnPFnPV/5Rsb4=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190507160741-ecd444e8653b/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190606165138-5da285871e9c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f h1:+Nyd8tzPX9R7BWHguqsrbFdRx3WQ/1ib8I44HXV5yTA=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210317225723-c4fcb01b228e h1:XNp2Flc/1eWQGk5BLzqTAN7fQIwIbfyVTuVxXxZh73M=
+golang.org/x/sys v0.0.0-20210317225723-c4fcb01b228e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20190311212946-11955173bddd h1:/e+gpKk9r3dJobndpTytxS2gOy6m5uvpg+ISQoEcusQ=
+golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/tools v0.0.0-20190312151545-0bb0c0a6e846/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190312170243-e65039ee4138/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190425150028-36563e24a262/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
+golang.org/x/tools v0.0.0-20190506145303-2d16b83fe98c/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
+golang.org/x/tools v0.0.0-20190606124116-d0a3d012864b/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
+golang.org/x/tools v0.0.0-20190621195816-6e04913cbbac/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
+golang.org/x/tools v0.0.0-20190628153133-6cdbf07be9d0/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
+golang.org/x/tools v0.0.0-20190816200558-6889da9d5479/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20190911174233-4f2ddba30aff/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191012152004-8de300cfc20a/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191112195655-aa38f8e97acc/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/api v0.4.0/go.mod h1:8k5glujaEP+g9n7WNsDg8QP6cUVNI86fCNMcbazEtwE=
+google.golang.org/api v0.7.0/go.mod h1:WtwebWUNSVBH/HAw79HIFXZNqEvBhG+Ra+ax0hx3E3M=
+google.golang.org/api v0.8.0/go.mod h1:o4eAsZoiT+ibD93RtjEohWalFOjRDx6CVaqeizhEnKg=
+google.golang.org/api v0.9.0/go.mod h1:o4eAsZoiT+ibD93RtjEohWalFOjRDx6CVaqeizhEnKg=
+google.golang.org/api v0.13.0/go.mod h1:iLdEw5Ide6rF15KTC1Kkl0iskquN2gFfn9o9XIsbkAI=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/appengine v1.6.1/go.mod h1:i06prIuMbXzDqacNJfV5OdTW448YApPu5ww/cMBSeb0=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/genproto v0.0.0-20190418145605-e7d98fc518a7/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/genproto v0.0.0-20190425155659-357c62f0e4bb/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/genproto v0.0.0-20190502173448-54afdca5d873/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/genproto v0.0.0-20190801165951-fa694d86fc64/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
+google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
+google.golang.org/genproto v0.0.0-20190911173649-1774047e7e51/go.mod h1:IbNlFCBrqXvoKpeg0TB2l7cyZUmoaFKYIwrEpbDKLA8=
+google.golang.org/genproto v0.0.0-20191108220845-16a3f7862a1a/go.mod h1:n3cpQtvxv34hfy77yVDNjmbRyujviMdxYliBSkLhpCc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
-google.golang.org/grpc v1.21.0/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
+google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
+google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/go-playground/assert.v1 v1.2.1/go.mod h1:9RXL0bg/zibRAgZUYszZSwO/z8Y/a8bDuhia5mkpMnE=
-gopkg.in/go-playground/validator.v9 v9.30.0/go.mod h1:+c9/zcJMFNgbLvly1L1V+PpxWdVbfP1avr/N00E2vyQ=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
+gopkg.in/ini.v1 v1.51.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473 h1:6D+BvnJ/j6e222UW8s2qTSe3wGBtvo0MbVQG/c5k8RE=
 gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473/go.mod h1:N1eN2tsCx0Ydtgjl4cqmbRCsY4/+z4cYDeqwZTk6zog=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 h1:tQIYjPdBoyREyB9XMu+nnTclpTYkz2zFM+lzLJFO4gQ=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
+rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=

pkg/yqlib/all_at_once_evaluator.go

@@ -1,29 +1,54 @@
 package yqlib
 
-import "container/list"
+import (
+	"container/list"
 
-/**
-	Loads all yaml documents of all files given into memory, then runs the given expression once.
-**/
+	yaml "gopkg.in/yaml.v3"
+)
+
+// A yaml expression evaluator that runs the expression once against all files/nodes in memory.
 type Evaluator interface {
 	EvaluateFiles(expression string, filenames []string, printer Printer) error
+
+	// EvaluateNodes takes an expression and one or more yaml nodes, returning a list of matching candidate nodes
+	EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error)
+
+	// EvaluateCandidateNodes takes an expression and list of candidate nodes, returning a list of matching candidate nodes
+	EvaluateCandidateNodes(expression string, inputCandidateNodes *list.List) (*list.List, error)
 }
 
 type allAtOnceEvaluator struct {
 	treeNavigator DataTreeNavigator
-	treeCreator   PathTreeCreator
+	treeCreator   ExpressionParser
 }
 
 func NewAllAtOnceEvaluator() Evaluator {
-	return &allAtOnceEvaluator{treeNavigator: NewDataTreeNavigator(), treeCreator: NewPathTreeCreator()}
+	return &allAtOnceEvaluator{treeNavigator: NewDataTreeNavigator(), treeCreator: NewExpressionParser()}
+}
+
+func (e *allAtOnceEvaluator) EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error) {
+	inputCandidates := list.New()
+	for _, node := range nodes {
+		inputCandidates.PushBack(&CandidateNode{Node: node})
+	}
+	return e.EvaluateCandidateNodes(expression, inputCandidates)
+}
+
+func (e *allAtOnceEvaluator) EvaluateCandidateNodes(expression string, inputCandidates *list.List) (*list.List, error) {
+	node, err := e.treeCreator.ParseExpression(expression)
+	if err != nil {
+		return nil, err
+	}
+	context, err := e.treeNavigator.GetMatchingNodes(Context{MatchingNodes: inputCandidates}, node)
+	if err != nil {
+		return nil, err
+	}
+	return context.MatchingNodes, nil
 }
 
 func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string, printer Printer) error {
 	fileIndex := 0
-	node, err := treeCreator.ParsePath(expression)
-	if err != nil {
-		return err
-	}
+
 	var allDocuments *list.List = list.New()
 	for _, filename := range filenames {
 		reader, err := readStream(filename)
@@ -37,7 +62,7 @@ func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string
 		allDocuments.PushBackList(fileDocuments)
 		fileIndex = fileIndex + 1
 	}
-	matches, err := treeNavigator.GetMatchingNodes(allDocuments, node)
+	matches, err := e.EvaluateCandidateNodes(expression, allDocuments)
 	if err != nil {
 		return err
 	}

pkg/yqlib/all_at_once_evaluator_test.go

@@ -0,0 +1,40 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var evaluateNodesScenario = []expressionScenario{
+	{
+		document:   `a: hello`,
+		expression: `.a`,
+		expected: []string{
+			"D0, P[a], (!!str)::hello\n",
+		},
+	},
+	{
+		document:   `a: hello`,
+		expression: `.`,
+		expected: []string{
+			"D0, P[], (doc)::a: hello\n",
+		},
+	},
+	{
+		document:   `- a: "yes"`,
+		expression: `.[] | has("a")`,
+		expected: []string{
+			"D0, P[0], (!!bool)::true\n",
+		},
+	},
+}
+
+func TestAllAtOnceEvaluateNodes(t *testing.T) {
+	var evaluator = NewAllAtOnceEvaluator()
+	for _, tt := range evaluateNodesScenario {
+		node := test.ParseData(tt.document)
+		list, _ := evaluator.EvaluateNodes(tt.expression, &node)
+		test.AssertResultComplex(t, tt.expected, resultsToString(list))
+	}
+}

pkg/yqlib/candidate_node.go

@@ -2,23 +2,55 @@ package yqlib
 
 import (
 	"fmt"
-	"strconv"
-	"strings"
 
 	"github.com/jinzhu/copier"
 	yaml "gopkg.in/yaml.v3"
 )
 
 type CandidateNode struct {
-	Node      *yaml.Node    // the actual node
-	Path      []interface{} /// the path we took to get to this node
-	Document  uint          // the document index of this node
+	Node      *yaml.Node     // the actual node
+	Parent    *CandidateNode // parent node
+	Path      []interface{}  /// the path we took to get to this node
+	Document  uint           // the document index of this node
 	Filename  string
 	FileIndex int
+	// when performing op against all nodes given, this will treat all the nodes as one
+	// (e.g. top level cross document merge). This property does not propegate to child nodes.
+	EvaluateTogether bool
+	IsMapKey         bool
 }
 
 func (n *CandidateNode) GetKey() string {
-	return fmt.Sprintf("%v - %v", n.Document, n.Path)
+	keyPrefix := ""
+	if n.IsMapKey {
+		keyPrefix = "key-"
+	}
+	return fmt.Sprintf("%v%v - %v", keyPrefix, n.Document, n.Path)
+}
+
+func (n *CandidateNode) CreateChild(path interface{}, node *yaml.Node) *CandidateNode {
+	return &CandidateNode{
+		Node:      node,
+		Path:      n.createChildPath(path),
+		Parent:    n,
+		Document:  n.Document,
+		Filename:  n.Filename,
+		FileIndex: n.FileIndex,
+	}
+}
+
+func (n *CandidateNode) createChildPath(path interface{}) []interface{} {
+	if path == nil {
+		newPath := make([]interface{}, len(n.Path))
+		copy(newPath, n.Path)
+		return newPath
+	}
+
+	//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) {
@@ -32,13 +64,14 @@ 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
-	n.Node.Alias = other.Node.Alias
 }
 
 func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode) {
+	log.Debug("UpdateAttributesFrom: n: %v other: %v", n.GetKey(), other.GetKey())
 	if n.Node.Kind != other.Node.Kind {
 		// clear out the contents when switching to a different type
 		// e.g. map to array
@@ -47,56 +80,22 @@ func (n *CandidateNode) UpdateAttributesFrom(other *CandidateNode) {
 	}
 	n.Node.Kind = other.Node.Kind
 	n.Node.Tag = other.Node.Tag
+	n.Node.Alias = other.Node.Alias
+	n.Node.Anchor = other.Node.Anchor
 
 	// merge will pickup the style of the new thing
 	// when autocreating nodes
 	if n.Node.Style == 0 {
 		n.Node.Style = other.Node.Style
 	}
-	n.Node.FootComment = n.Node.FootComment + other.Node.FootComment
-	n.Node.HeadComment = n.Node.HeadComment + other.Node.HeadComment
-	n.Node.LineComment = n.Node.LineComment + other.Node.LineComment
-}
 
-func (n *CandidateNode) PathStackToString() string {
-	return mergePathStackToString(n.Path)
-}
-
-func mergePathStackToString(pathStack []interface{}) string {
-	var sb strings.Builder
-	for index, path := range pathStack {
-		switch path.(type) {
-		case int, int64:
-			// if arrayMergeStrategy == AppendArrayMergeStrategy {
-			// sb.WriteString("[+]")
-			// } else {
-			sb.WriteString(fmt.Sprintf("[%v]", path))
-			// }
-
-		default:
-			s := fmt.Sprintf("%v", path)
-			var _, errParsingInt = strconv.ParseInt(s, 10, 64) // nolint
-
-			hasSpecial := strings.Contains(s, ".") || strings.Contains(s, "[") || strings.Contains(s, "]") || strings.Contains(s, "\"")
-			hasDoubleQuotes := strings.Contains(s, "\"")
-			wrappingCharacterStart := "\""
-			wrappingCharacterEnd := "\""
-			if hasDoubleQuotes {
-				wrappingCharacterStart = "("
-				wrappingCharacterEnd = ")"
-			}
-			if hasSpecial || errParsingInt == nil {
-				sb.WriteString(wrappingCharacterStart)
-			}
-			sb.WriteString(s)
-			if hasSpecial || errParsingInt == nil {
-				sb.WriteString(wrappingCharacterEnd)
-			}
-		}
-
-		if index < len(pathStack)-1 {
-			sb.WriteString(".")
-		}
+	if other.Node.FootComment != "" {
+		n.Node.FootComment = other.Node.FootComment
+	}
+	if other.Node.HeadComment != "" {
+		n.Node.HeadComment = other.Node.HeadComment
+	}
+	if other.Node.LineComment != "" {
+		n.Node.LineComment = other.Node.LineComment
 	}
-	return sb.String()
 }

pkg/yqlib/color_print.go

@@ -17,8 +17,8 @@ func format(attr color.Attribute) string {
 	return fmt.Sprintf("%s[%dm", escape, attr)
 }
 
-func ColorizeAndPrint(bytes []byte, writer io.Writer) error {
-	tokens := lexer.Tokenize(string(bytes))
+func colorizeAndPrint(yamlBytes []byte, writer io.Writer) error {
+	tokens := lexer.Tokenize(string(yamlBytes))
 	var p printer.Printer
 	p.Bool = func() *printer.Property {
 		return &printer.Property{

pkg/yqlib/constants.go

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

pkg/yqlib/context.go

@@ -0,0 +1,68 @@
+package yqlib
+
+import (
+	"container/list"
+
+	"github.com/jinzhu/copier"
+)
+
+type Context struct {
+	MatchingNodes  *list.List
+	Variables      map[string]*list.List
+	DontAutoCreate bool
+}
+
+func (n *Context) SingleReadonlyChildContext(candidate *CandidateNode) Context {
+	list := list.New()
+	list.PushBack(candidate)
+	newContext := n.ChildContext(list)
+	newContext.DontAutoCreate = true
+	return newContext
+}
+
+func (n *Context) SingleChildContext(candidate *CandidateNode) Context {
+	list := list.New()
+	list.PushBack(candidate)
+	return n.ChildContext(list)
+}
+
+func (n *Context) GetVariable(name string) *list.List {
+	if n.Variables == nil {
+		return nil
+	}
+	return n.Variables[name]
+}
+
+func (n *Context) SetVariable(name string, value *list.List) {
+	if n.Variables == nil {
+		n.Variables = make(map[string]*list.List)
+	}
+	n.Variables[name] = value
+}
+
+func (n *Context) ChildContext(results *list.List) Context {
+	clone := Context{}
+	err := copier.Copy(&clone, n)
+	if err != nil {
+		log.Error("Error cloning context :(")
+		panic(err)
+	}
+	clone.MatchingNodes = results
+	return clone
+}
+
+func (n *Context) Clone() Context {
+	clone := Context{}
+	err := copier.Copy(&clone, n)
+	if err != nil {
+		log.Error("Error cloning context :(")
+		panic(err)
+	}
+	return clone
+}
+
+func (n *Context) ReadOnlyClone() Context {
+	clone := n.Clone()
+	clone.DontAutoCreate = true
+	return clone
+}

pkg/yqlib/data_tree_navigator.go

@@ -3,16 +3,14 @@ package yqlib
 import (
 	"fmt"
 
-	"container/list"
-
 	logging "gopkg.in/op/go-logging.v1"
 )
 
 type DataTreeNavigator interface {
-	// given a list of CandidateEntities and a pathNode,
-	// this will process the list against the given pathNode and return
-	// a new list of matching candidates
-	GetMatchingNodes(matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error)
+	// given the context and a expressionNode,
+	// this will process the against the given expressionNode and return
+	// a new context of matching candidates
+	GetMatchingNodes(context Context, expressionNode *ExpressionNode) (Context, error)
 }
 
 type dataTreeNavigator struct {
@@ -22,22 +20,22 @@ func NewDataTreeNavigator() DataTreeNavigator {
 	return &dataTreeNavigator{}
 }
 
-func (d *dataTreeNavigator) GetMatchingNodes(matchingNodes *list.List, pathNode *PathTreeNode) (*list.List, error) {
-	if pathNode == nil {
+func (d *dataTreeNavigator) GetMatchingNodes(context Context, expressionNode *ExpressionNode) (Context, error) {
+	if expressionNode == nil {
 		log.Debugf("getMatchingNodes - nothing to do")
-		return matchingNodes, nil
+		return context, nil
 	}
-	log.Debugf("Processing Op: %v", pathNode.Operation.toString())
+	log.Debugf("Processing Op: %v", expressionNode.Operation.toString())
 	if log.IsEnabledFor(logging.DEBUG) {
-		for el := matchingNodes.Front(); el != nil; el = el.Next() {
+		for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 			log.Debug(NodeToString(el.Value.(*CandidateNode)))
 		}
 	}
 	log.Debug(">>")
-	handler := pathNode.Operation.OperationType.Handler
+	handler := expressionNode.Operation.OperationType.Handler
 	if handler != nil {
-		return handler(d, matchingNodes, pathNode)
+		return handler(d, context, expressionNode)
 	}
-	return nil, fmt.Errorf("Unknown operator %v", pathNode.Operation.OperationType)
+	return Context{}, fmt.Errorf("Unknown operator %v", expressionNode.Operation.OperationType)
 
 }

pkg/yqlib/doc/.gitignore

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

pkg/yqlib/doc/Add.md

@@ -1,7 +1,33 @@
 Add behaves differently according to the type of the LHS:
 - arrays: concatenate
-- number scalars: arithmetic addition (soon)
-- string scalars: concatenate (soon)
+- number scalars: arithmetic addition
+- string scalars: concatenate
+
+Use `+=` as append assign for things like increment. Note that `.a += .x` is equivalent to running `.a = .a + .x`.
+
+## Concatenate and assign arrays
+Given a sample.yml file of:
+```yaml
+a:
+  val: thing
+  b:
+    - cat
+    - dog
+```
+then
+```bash
+yq eval '.a.b += ["cow"]' sample.yml
+```
+will output
+```yaml
+a:
+  val: thing
+  b:
+    - cat
+    - dog
+    - cow
+```
+
 ## Concatenate arrays
 Given a sample.yml file of:
 ```yaml
@@ -41,23 +67,19 @@ will output
 - 2
 ```
 
-## Add object to array
+## Add new object to array
 Given a sample.yml file of:
 ```yaml
 a:
-  - 1
-  - 2
-c:
-  cat: meow
+  - dog: woof
 ```
 then
 ```bash
-yq eval '.a + .c' sample.yml
+yq eval '.a + {"cat": "meow"}' sample.yml
 ```
 will output
 ```yaml
-- 1
-- 2
+- dog: woof
 - cat: meow
 ```
 
@@ -79,7 +101,7 @@ will output
 - hello
 ```
 
-## Update array (append)
+## Append to array
 Given a sample.yml file of:
 ```yaml
 a:
@@ -105,3 +127,113 @@ b:
   - 4
 ```
 
+## Relative append
+Given a sample.yml file of:
+```yaml
+a:
+  a1:
+    b:
+      - cat
+  a2:
+    b:
+      - dog
+  a3: {}
+```
+then
+```bash
+yq eval '.a[].b += ["mouse"]' sample.yml
+```
+will output
+```yaml
+a:
+  a1:
+    b:
+      - cat
+      - mouse
+  a2:
+    b:
+      - dog
+      - mouse
+  a3: {b: [mouse]}
+```
+
+## String concatenation
+Given a sample.yml file of:
+```yaml
+a: cat
+b: meow
+```
+then
+```bash
+yq eval '.a = .a + .b' sample.yml
+```
+will output
+```yaml
+a: catmeow
+b: meow
+```
+
+## Number addition - float
+If the lhs or rhs are floats then the expression will be calculated with floats.
+
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4.9
+```
+then
+```bash
+yq eval '.a = .a + .b' sample.yml
+```
+will output
+```yaml
+a: 7.9
+b: 4.9
+```
+
+## Number addition - int
+If both the lhs and rhs are ints then the expression will be calculated with ints.
+
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4
+```
+then
+```bash
+yq eval '.a = .a + .b' sample.yml
+```
+will output
+```yaml
+a: 7
+b: 4
+```
+
+## Increment numbers
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 5
+```
+then
+```bash
+yq eval '.[] += 1' sample.yml
+```
+will output
+```yaml
+a: 4
+b: 6
+```
+
+## Add to null
+Adding to null simply returns the rhs
+
+Running
+```bash
+yq eval --null-input 'null + "cat"'
+```
+will output
+```yaml
+cat
+```
+

pkg/yqlib/doc/Alternative (Default value).md

@@ -0,0 +1,73 @@
+This operator is used to provide alternative (or default) values when a particular expression is either null or false.
+
+## LHS is defined
+Given a sample.yml file of:
+```yaml
+a: bridge
+```
+then
+```bash
+yq eval '.a // "hello"' sample.yml
+```
+will output
+```yaml
+bridge
+```
+
+## LHS is not defined
+Given a sample.yml file of:
+```yaml
+{}
+```
+then
+```bash
+yq eval '.a // "hello"' sample.yml
+```
+will output
+```yaml
+hello
+```
+
+## LHS is null
+Given a sample.yml file of:
+```yaml
+a: ~
+```
+then
+```bash
+yq eval '.a // "hello"' sample.yml
+```
+will output
+```yaml
+hello
+```
+
+## LHS is false
+Given a sample.yml file of:
+```yaml
+a: false
+```
+then
+```bash
+yq eval '.a // "hello"' sample.yml
+```
+will output
+```yaml
+hello
+```
+
+## RHS is an expression
+Given a sample.yml file of:
+```yaml
+a: false
+b: cat
+```
+then
+```bash
+yq eval '.a // .b' sample.yml
+```
+will output
+```yaml
+cat
+```
+

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

@@ -0,0 +1,301 @@
+Use the `alias` and `anchor` operators to read and write yaml aliases and anchors. The `explode` operator normalises a yaml file (dereference (or expands) aliases and remove anchor names).
+
+`yq` supports merge aliases (like `<<: *blah`) however this is no longer in the standard yaml spec (1.2) and so `yq` will automatically add the `!!merge` tag to these nodes as it is effectively a custom tag.
+
+
+## Merge one map
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<: *CENTER
+  r: 10
+```
+then
+```bash
+yq eval '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+x: 1
+y: 2
+r: 10
+```
+
+## Merge multiple maps
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<:
+    - *CENTER
+    - *BIG
+```
+then
+```bash
+yq eval '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+r: 10
+x: 1
+y: 2
+```
+
+## Override
+see https://yaml.org/type/merge.html
+
+Given a sample.yml file of:
+```yaml
+- &CENTER
+  x: 1
+  y: 2
+- &LEFT
+  x: 0
+  y: 2
+- &BIG
+  r: 10
+- &SMALL
+  r: 1
+- !!merge <<:
+    - *BIG
+    - *LEFT
+    - *SMALL
+  x: 1
+```
+then
+```bash
+yq eval '.[4] | explode(.)' sample.yml
+```
+will output
+```yaml
+r: 10
+x: 1
+y: 2
+```
+
+## Get anchor
+Given a sample.yml file of:
+```yaml
+a: &billyBob cat
+```
+then
+```bash
+yq eval '.a | anchor' sample.yml
+```
+will output
+```yaml
+billyBob
+```
+
+## Set anchor
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval '.a anchor = "foobar"' sample.yml
+```
+will output
+```yaml
+a: &foobar cat
+```
+
+## Set anchor relatively using assign-update
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a anchor |= .b' sample.yml
+```
+will output
+```yaml
+a: &cat
+  b: cat
+```
+
+## Get alias
+Given a sample.yml file of:
+```yaml
+b: &billyBob meow
+a: *billyBob
+```
+then
+```bash
+yq eval '.a | alias' sample.yml
+```
+will output
+```yaml
+billyBob
+```
+
+## Set alias
+Given a sample.yml file of:
+```yaml
+b: &meow purr
+a: cat
+```
+then
+```bash
+yq eval '.a alias = "meow"' sample.yml
+```
+will output
+```yaml
+b: &meow purr
+a: *meow
+```
+
+## Set alias to blank does nothing
+Given a sample.yml file of:
+```yaml
+b: &meow purr
+a: cat
+```
+then
+```bash
+yq eval '.a alias = ""' sample.yml
+```
+will output
+```yaml
+b: &meow purr
+a: cat
+```
+
+## Set alias relatively using assign-update
+Given a sample.yml file of:
+```yaml
+b: &meow purr
+a:
+  f: meow
+```
+then
+```bash
+yq 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
+f:
+  a: &a cat
+  b: *a
+```
+then
+```bash
+yq eval 'explode(.f)' sample.yml
+```
+will output
+```yaml
+f:
+  a: cat
+  b: cat
+```
+
+## Explode with no aliases or anchors
+Given a sample.yml file of:
+```yaml
+a: mike
+```
+then
+```bash
+yq eval 'explode(.a)' sample.yml
+```
+will output
+```yaml
+a: mike
+```
+
+## Explode with alias keys
+Given a sample.yml file of:
+```yaml
+f:
+  a: &a cat
+  *a: b
+```
+then
+```bash
+yq eval 'explode(.f)' sample.yml
+```
+will output
+```yaml
+f:
+  a: cat
+  cat: b
+```
+
+## Explode with merge anchors
+Given a sample.yml file of:
+```yaml
+foo: &foo
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar: &bar
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: foobarList_b
+  !!merge <<:
+    - *foo
+    - *bar
+  c: foobarList_c
+foobar:
+  c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+```
+then
+```bash
+yq eval 'explode(.)' sample.yml
+```
+will output
+```yaml
+foo:
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar:
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: bar_b
+  thing: foo_thing
+  c: foobarList_c
+  a: foo_a
+foobar:
+  c: foo_c
+  a: foo_a
+  thing: foobar_thing
+```
+

pkg/yqlib/doc/Assign (Update).md

@@ -1,10 +1,16 @@
-This operator is used to update node values. It can be used in either the:
 
-### plain form: `=`
-Which will assign the LHS node values to the RHS node values. The RHS expression is run against the matching nodes in the pipeline.
+## Create yaml file
+Running
+```bash
+yq eval --null-input '.a.b = "cat" | .x = "frog"'
+```
+will output
+```yaml
+a:
+  b: cat
+x: frog
+```
 
-### relative form: `|=`
-This will do a similar thing to the plain form, however, the RHS expression is run against _the LHS nodes_. This is useful for updating values based on old values, e.g. increment.
 ## Update node to be the child value
 Given a sample.yml file of:
 ```yaml
@@ -22,6 +28,27 @@ 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
@@ -100,7 +127,7 @@ a:
 ```
 then
 ```bash
-yq eval '.a.[] | select(. == "apple") |= "frog"' sample.yml
+yq eval '(.a[] | select(. == "apple")) = "frog"' sample.yml
 ```
 will output
 ```yaml
@@ -118,7 +145,7 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '.[] | select(. == "*andy") |= "bogs"' sample.yml
+yq eval '(.[] | select(. == "*andy")) = "bogs"' sample.yml
 ```
 will output
 ```yaml
@@ -148,7 +175,7 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '.a.b[0] |= "bogs"' sample.yml
+yq eval '.a.b.[0] |= "bogs"' sample.yml
 ```
 will output
 ```yaml

pkg/yqlib/doc/Boolean Operators.md

@@ -1,5 +1,14 @@
-The `or` and `and` operators take two parameters and return a boolean result. `not` flips a boolean from true to false, or vice versa. These are most commonly used with the `select` operator to filter particular nodes.
-## OR example
+The `or` and `and` operators take two parameters and return a boolean result. 
+
+`not` flips a boolean from true to false, or vice versa. 
+
+`any` will return `true` if there are any `true` values in a array sequence, and `all` will return true if _all_ elements in an array are true.
+
+`any_c(condition)` and `all_c(condition)` are like `any` and `all` but they take a condition expression that is used against each element to determine if it's `true`. Note: in `jq` you can simply pass a condition to `any` or `all` and it simply works - `yq` isn't that clever..yet
+
+These are most commonly used with the `select` operator to filter particular nodes.
+
+## `or` example
 Running
 ```bash
 yq eval --null-input 'true or false'
@@ -9,7 +18,7 @@ will output
 true
 ```
 
-## AND example
+## `and` example
 Running
 ```bash
 yq eval --null-input 'true and false'
@@ -41,6 +50,104 @@ will output
   b: fly
 ```
 
+## `any` returns true if any boolean in a given array is true
+Given a sample.yml file of:
+```yaml
+- false
+- true
+```
+then
+```bash
+yq eval 'any' sample.yml
+```
+will output
+```yaml
+true
+```
+
+## `any` returns false for an empty array
+Given a sample.yml file of:
+```yaml
+[]
+```
+then
+```bash
+yq eval 'any' sample.yml
+```
+will output
+```yaml
+false
+```
+
+## `any_c` returns true if any element in the array is true for the given condition.
+Given a sample.yml file of:
+```yaml
+a:
+  - rad
+  - awesome
+b:
+  - meh
+  - whatever
+```
+then
+```bash
+yq eval '.[] |= any_c(. == "awesome")' sample.yml
+```
+will output
+```yaml
+a: true
+b: false
+```
+
+## `all` returns true if all booleans in a given array are true
+Given a sample.yml file of:
+```yaml
+- true
+- true
+```
+then
+```bash
+yq eval 'all' sample.yml
+```
+will output
+```yaml
+true
+```
+
+## `all` returns true for an empty array
+Given a sample.yml file of:
+```yaml
+[]
+```
+then
+```bash
+yq eval 'all' sample.yml
+```
+will output
+```yaml
+true
+```
+
+## `all_c` returns true if all elements in the array are true for the given condition.
+Given a sample.yml file of:
+```yaml
+a:
+  - rad
+  - awesome
+b:
+  - meh
+  - 12
+```
+then
+```bash
+yq eval '.[] |= all_c(tag == "!!str")' sample.yml
+```
+will output
+```yaml
+a: true
+b: false
+```
+
 ## Not true is false
 Running
 ```bash

pkg/yqlib/doc/Comment Operators.md

@@ -1,4 +1,15 @@
 Use these comment operators to set or retrieve comments.
+
+Like the `=` and `|=` assign operators, the same syntax applies when updating comments:
+
+
+### plain form: `=`
+This will assign the LHS nodes comments to the expression on the RHS. The RHS is run against the matching nodes in the pipeline
+
+### relative form: `|=` 
+Similar to the plain form, however the RHS evaluates against each matching LHS node! This is useful if you want to set the comments as a relative expression of the node, for instance its value or path.
+
+
 ## Set line comment
 Given a sample.yml file of:
 ```yaml
@@ -13,6 +24,22 @@ 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
@@ -61,18 +88,23 @@ a: cat
 b: dog # leave this
 ```
 
-## Remove all comments
+## Remove (strip) all comments
+Note the use of `...` to ensure key nodes are included.
+
 Given a sample.yml file of:
 ```yaml
 a: cat # comment
+# great
+b: # key comment
 ```
 then
 ```bash
-yq eval '.. comments=""' sample.yml
+yq eval '... comments=""' sample.yml
 ```
 will output
 ```yaml
 a: cat
+b:
 ```
 
 ## Get line comment

pkg/yqlib/doc/Delete.md

@@ -14,6 +14,23 @@ will output
 a: cat
 ```
 
+## Delete nested entry in map
+Given a sample.yml file of:
+```yaml
+a:
+  a1: fred
+  a2: frood
+```
+then
+```bash
+yq eval 'del(.a.a1)' sample.yml
+```
+will output
+```yaml
+a:
+  a2: frood
+```
+
 ## Delete entry in array
 Given a sample.yml file of:
 ```yaml
@@ -31,6 +48,21 @@ will output
 - 3
 ```
 
+## Delete nested entry in array
+Given a sample.yml file of:
+```yaml
+- a: cat
+  b: dog
+```
+then
+```bash
+yq eval 'del(.[0].a)' sample.yml
+```
+will output
+```yaml
+- b: dog
+```
+
 ## Delete no matches
 Given a sample.yml file of:
 ```yaml
@@ -63,3 +95,23 @@ will output
 b: dog
 ```
 
+## Recursively delete matching keys
+Given a sample.yml file of:
+```yaml
+a:
+  name: frog
+  b:
+    name: blog
+    age: 12
+```
+then
+```bash
+yq eval 'del(.. | select(has("name")).name)' sample.yml
+```
+will output
+```yaml
+a:
+  b:
+    age: 12
+```
+

pkg/yqlib/doc/Document Index.md

@@ -1,4 +1,4 @@
-Use the `documentIndex` operator to select nodes of a particular document.
+Use the `documentIndex` operator (or the `di` shorthand) to select nodes of a particular document.
 ## Retrieve a document index
 Given a sample.yml file of:
 ```yaml
@@ -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/Entries.md

@@ -0,0 +1,100 @@
+Similar to the same named functions in `jq` these functions convert to/from an object and an array of key-value pairs. This is most useful for performing operations on keys of maps.
+## to_entries Map
+Given a sample.yml file of:
+```yaml
+a: 1
+b: 2
+```
+then
+```bash
+yq eval 'to_entries' sample.yml
+```
+will output
+```yaml
+- key: a
+  value: 1
+- key: b
+  value: 2
+```
+
+## to_entries Array
+Given a sample.yml file of:
+```yaml
+- a
+- b
+```
+then
+```bash
+yq eval 'to_entries' sample.yml
+```
+will output
+```yaml
+- key: 0
+  value: a
+- key: 1
+  value: b
+```
+
+## to_entries null
+Given a sample.yml file of:
+```yaml
+null
+```
+then
+```bash
+yq eval 'to_entries' sample.yml
+```
+will output
+```yaml
+```
+
+## from_entries map
+Given a sample.yml file of:
+```yaml
+a: 1
+b: 2
+```
+then
+```bash
+yq eval 'to_entries | from_entries' sample.yml
+```
+will output
+```yaml
+a: 1
+b: 2
+```
+
+## from_entries with numeric key indexes
+from_entries always creates a map, even for numeric keys
+
+Given a sample.yml file of:
+```yaml
+- a
+- b
+```
+then
+```bash
+yq eval 'to_entries | from_entries' sample.yml
+```
+will output
+```yaml
+0: a
+1: b
+```
+
+## Use with_entries to update keys
+Given a sample.yml file of:
+```yaml
+a: 1
+b: 2
+```
+then
+```bash
+yq eval 'with_entries(.key |= "KEY_" + .)' sample.yml
+```
+will output
+```yaml
+KEY_a: 1
+KEY_b: 2
+```
+

pkg/yqlib/doc/Env Variable Operators.md

@@ -0,0 +1,78 @@
+This operator is used to handle environment variables usage in path expressions. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. Note that there are two forms, `env` which will parse the environment variable as a yaml (be it a map, array, string, number of boolean) and `strenv` which will always parse the argument as a string.
+
+
+## Read string environment variable
+Running
+```bash
+myenv="cat meow" yq eval --null-input '.a = env(myenv)'
+```
+will output
+```yaml
+a: cat meow
+```
+
+## Read boolean environment variable
+Running
+```bash
+myenv="true" yq eval --null-input '.a = env(myenv)'
+```
+will output
+```yaml
+a: true
+```
+
+## Read numeric environment variable
+Running
+```bash
+myenv="12" yq eval --null-input '.a = env(myenv)'
+```
+will output
+```yaml
+a: 12
+```
+
+## Read yaml environment variable
+Running
+```bash
+myenv="{b: fish}" yq eval --null-input '.a = env(myenv)'
+```
+will output
+```yaml
+a: {b: fish}
+```
+
+## Read boolean environment variable as a string
+Running
+```bash
+myenv="true" yq eval --null-input '.a = strenv(myenv)'
+```
+will output
+```yaml
+a: "true"
+```
+
+## Read numeric environment variable as a string
+Running
+```bash
+myenv="12" yq eval --null-input '.a = strenv(myenv)'
+```
+will output
+```yaml
+a: "12"
+```
+
+## Dynamic key lookup with environment variable
+Given a sample.yml file of:
+```yaml
+cat: meow
+dog: woof
+```
+then
+```bash
+myenv="cat" yq eval '.[env(myenv)]' sample.yml
+```
+will output
+```yaml
+meow
+```
+

pkg/yqlib/doc/Equals.md

@@ -29,6 +29,24 @@ true
 false
 ```
 
+## Don't match string
+Given a sample.yml file of:
+```yaml
+- cat
+- goat
+- dog
+```
+then
+```bash
+yq eval '.[] | (. != "*at")' sample.yml
+```
+will output
+```yaml
+false
+false
+true
+```
+
 ## Match number
 Given a sample.yml file of:
 ```yaml
@@ -47,6 +65,24 @@ true
 false
 ```
 
+## Dont match number
+Given a sample.yml file of:
+```yaml
+- 3
+- 4
+- 5
+```
+then
+```bash
+yq eval '.[] | (. != 4)' sample.yml
+```
+will output
+```yaml
+true
+false
+true
+```
+
 ## Match nulls
 Running
 ```bash
@@ -57,3 +93,31 @@ will output
 true
 ```
 
+## Non exisitant key doesn't equal a value
+Given a sample.yml file of:
+```yaml
+a: frog
+```
+then
+```bash
+yq eval 'select(.b != "thing")' sample.yml
+```
+will output
+```yaml
+a: frog
+```
+
+## Two non existant keys are equal
+Given a sample.yml file of:
+```yaml
+a: frog
+```
+then
+```bash
+yq eval 'select(.b == .c)' sample.yml
+```
+will output
+```yaml
+a: frog
+```
+

pkg/yqlib/doc/Explode.md

@@ -1,98 +0,0 @@
-Explodes (or dereferences) aliases and anchors.
-## Explode alias and anchor
-Given a sample.yml file of:
-```yaml
-f:
-  a: &a cat
-  b: *a
-```
-then
-```bash
-yq eval 'explode(.f)' sample.yml
-```
-will output
-```yaml
-f:
-  a: cat
-  b: cat
-```
-
-## Explode with no aliases or anchors
-Given a sample.yml file of:
-```yaml
-a: mike
-```
-then
-```bash
-yq eval 'explode(.a)' sample.yml
-```
-will output
-```yaml
-a: mike
-```
-
-## Explode with alias keys
-Given a sample.yml file of:
-```yaml
-f:
-  a: &a cat
-  *a: b
-```
-then
-```bash
-yq eval 'explode(.f)' sample.yml
-```
-will output
-```yaml
-f:
-  a: cat
-  cat: b
-```
-
-## Explode with merge anchors
-Given a sample.yml file of:
-```yaml
-foo: &foo
-  a: foo_a
-  thing: foo_thing
-  c: foo_c
-bar: &bar
-  b: bar_b
-  thing: bar_thing
-  c: bar_c
-foobarList:
-  b: foobarList_b
-  !!merge <<:
-    - *foo
-    - *bar
-  c: foobarList_c
-foobar:
-  c: foobar_c
-  !!merge <<: *foo
-  thing: foobar_thing
-```
-then
-```bash
-yq eval 'explode(.)' sample.yml
-```
-will output
-```yaml
-foo:
-  a: foo_a
-  thing: foo_thing
-  c: foo_c
-bar:
-  b: bar_b
-  thing: bar_thing
-  c: bar_c
-foobarList:
-  b: bar_b
-  a: foo_a
-  thing: bar_thing
-  c: foobarList_c
-foobar:
-  c: foo_c
-  a: foo_a
-  thing: foobar_thing
-```
-

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 +35,37 @@ will output
 0
 ```
 
+## Get file indices of multiple documents
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+And another sample another.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval-all 'fileIndex' sample.yml another.yml
+```
+will output
+```yaml
+0
+---
+1
+```
+
+## 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/Has.md

@@ -19,6 +19,29 @@ true
 false
 ```
 
+## Select, checking for existence of deep paths
+Simply pipe in parent expressions into `has`
+
+Given a sample.yml file of:
+```yaml
+- a:
+    b:
+      c: cat
+- a:
+    b:
+      d: dog
+```
+then
+```bash
+yq eval '.[] | select(.a.b | has("c"))' sample.yml
+```
+will output
+```yaml
+a:
+  b:
+    c: cat
+```
+
 ## Has array index
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Keys.md

@@ -0,0 +1,35 @@
+# Keys
+
+Use the `keys` operator to return map keys or array indices. 
+## Map keys
+Given a sample.yml file of:
+```yaml
+dog: woof
+cat: meow
+```
+then
+```bash
+yq eval 'keys' sample.yml
+```
+will output
+```yaml
+- dog
+- cat
+```
+
+## Array keys
+Given a sample.yml file of:
+```yaml
+- apple
+- banana
+```
+then
+```bash
+yq eval 'keys' sample.yml
+```
+will output
+```yaml
+- 0
+- 1
+```
+

pkg/yqlib/doc/Length.md

@@ -0,0 +1,68 @@
+Returns the lengths of the nodes. Length is defined according to the type of the node.
+
+## String length
+returns length of string
+
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval '.a | length' sample.yml
+```
+will output
+```yaml
+3
+```
+
+## null length
+Given a sample.yml file of:
+```yaml
+a: null
+```
+then
+```bash
+yq eval '.a | length' sample.yml
+```
+will output
+```yaml
+0
+```
+
+## Map length
+returns number of entries
+
+Given a sample.yml file of:
+```yaml
+a: cat
+c: dog
+```
+then
+```bash
+yq eval 'length' sample.yml
+```
+will output
+```yaml
+2
+```
+
+## Array length
+returns number of elements
+
+Given a sample.yml file of:
+```yaml
+- 2
+- 4
+- 6
+- 8
+```
+then
+```bash
+yq eval 'length' sample.yml
+```
+will output
+```yaml
+4
+```
+

pkg/yqlib/doc/Multiply (Merge).md

@@ -0,0 +1,366 @@
+Like the multiple operator in jq, depending on the operands, this multiply operator will do different things. Currently numbers, arrays and objects are supported.
+
+## Objects and arrays - merging
+Objects are merged deeply matching on matching keys. By default, array values override and are not deeply merged.
+
+Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
+
+### Merge Flags
+You can control how objects are merged by using one or more of the following flags. Multiple flags can be used together, e.g. `.a *+? .b`.  See examples below
+
+- `+` to append arrays
+- `?` to only merge existing fields
+- `d` to deeply merge arrays
+
+### Merging files
+Note the use of `eval-all` to ensure all documents are loaded into memory.
+
+```bash
+yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
+```
+
+## Multiply integers
+Running
+```bash
+yq eval --null-input '3 * 4'
+```
+will output
+```yaml
+12
+```
+
+## Merge objects together, returning merged result only
+Given a sample.yml file of:
+```yaml
+a:
+  field: me
+  fieldA: cat
+b:
+  field:
+    g: wizz
+  fieldB: dog
+```
+then
+```bash
+yq eval '.a * .b' sample.yml
+```
+will output
+```yaml
+field:
+  g: wizz
+fieldA: cat
+fieldB: dog
+```
+
+## Merge objects together, returning parent object
+Given a sample.yml file of:
+```yaml
+a:
+  field: me
+  fieldA: cat
+b:
+  field:
+    g: wizz
+  fieldB: dog
+```
+then
+```bash
+yq eval '. * {"a":.b}' sample.yml
+```
+will output
+```yaml
+a:
+  field:
+    g: wizz
+  fieldA: cat
+  fieldB: dog
+b:
+  field:
+    g: wizz
+  fieldB: dog
+```
+
+## Merge keeps style of LHS
+Given a sample.yml file of:
+```yaml
+a: {things: great}
+b:
+  also: "me"
+```
+then
+```bash
+yq eval '. * {"a":.b}' sample.yml
+```
+will output
+```yaml
+a: {things: great, also: "me"}
+b:
+  also: "me"
+```
+
+## Merge arrays
+Given a sample.yml file of:
+```yaml
+a:
+  - 1
+  - 2
+  - 3
+b:
+  - 3
+  - 4
+  - 5
+```
+then
+```bash
+yq eval '. * {"a":.b}' sample.yml
+```
+will output
+```yaml
+a:
+  - 3
+  - 4
+  - 5
+b:
+  - 3
+  - 4
+  - 5
+```
+
+## Merge, only existing fields
+Given a sample.yml file of:
+```yaml
+a:
+  thing: one
+  cat: frog
+b:
+  missing: two
+  thing: two
+```
+then
+```bash
+yq eval '.a *? .b' sample.yml
+```
+will output
+```yaml
+thing: two
+cat: frog
+```
+
+## Merge, appending arrays
+Given a sample.yml file of:
+```yaml
+a:
+  array:
+    - 1
+    - 2
+    - animal: dog
+  value: coconut
+b:
+  array:
+    - 3
+    - 4
+    - animal: cat
+  value: banana
+```
+then
+```bash
+yq eval '.a *+ .b' sample.yml
+```
+will output
+```yaml
+array:
+  - 1
+  - 2
+  - animal: dog
+  - 3
+  - 4
+  - animal: cat
+value: banana
+```
+
+## Merge, only existing fields, appending arrays
+Given a sample.yml file of:
+```yaml
+a:
+  thing:
+    - 1
+    - 2
+b:
+  thing:
+    - 3
+    - 4
+  another:
+    - 1
+```
+then
+```bash
+yq eval '.a *?+ .b' sample.yml
+```
+will output
+```yaml
+thing:
+  - 1
+  - 2
+  - 3
+  - 4
+```
+
+## Merge, deeply merging arrays
+Merging arrays deeply means arrays are merge like objects, with indexes as their key. In this case, we merge the first item in the array, and do nothing with the second.
+
+Given a sample.yml file of:
+```yaml
+a:
+  - name: fred
+    age: 12
+  - name: bob
+    age: 32
+b:
+  - name: fred
+    age: 34
+```
+then
+```bash
+yq eval '.a *d .b' sample.yml
+```
+will output
+```yaml
+- name: fred
+  age: 34
+- name: bob
+  age: 32
+```
+
+## Merge arrays of objects together, matching on a key
+It's a complex command, the trickyness comes from needing to have the right context in the expressions.
+First we save the second array into a variable '$two' which lets us reference it later.
+We then need to update the first array. We will use the relative update (|=) because we need to update relative to the current element of the array in the LHS in the RHS expression. 
+We set the current element of the first array as $cur. Now we multiply (merge) $cur with the matching entry in $two, by passing $two through a select filter.
+
+
+Given a sample.yml file of:
+```yaml
+- a: apple
+  b: appleB
+- a: kiwi
+  b: kiwiB
+- a: banana
+  b: bananaB
+```
+And another sample another.yml file of:
+```yaml
+- a: banana
+  c: bananaC
+- a: apple
+  b: appleB2
+- a: dingo
+  c: dingoC
+```
+then
+```bash
+yq eval-all '(select(fi==1) | .[]) as $two | select(fi==0) | .[] |= (. as $cur |  $cur * ($two | select(.a == $cur.a)))' sample.yml another.yml
+```
+will output
+```yaml
+- a: apple
+  b: appleB2
+- a: kiwi
+  b: kiwiB
+- a: banana
+  b: bananaB
+  c: bananaC
+```
+
+## Merge to prefix an element
+Given a sample.yml file of:
+```yaml
+a: cat
+b: dog
+```
+then
+```bash
+yq eval '. * {"a": {"c": .a}}' sample.yml
+```
+will output
+```yaml
+a:
+  c: cat
+b: dog
+```
+
+## Merge with simple aliases
+Given a sample.yml file of:
+```yaml
+a: &cat
+  c: frog
+b:
+  f: *cat
+c:
+  g: thongs
+```
+then
+```bash
+yq eval '.c * .b' sample.yml
+```
+will output
+```yaml
+g: thongs
+f: *cat
+```
+
+## Merge copies anchor names
+Given a sample.yml file of:
+```yaml
+a:
+  c: &cat frog
+b:
+  f: *cat
+c:
+  g: thongs
+```
+then
+```bash
+yq eval '.c * .a' sample.yml
+```
+will output
+```yaml
+g: thongs
+c: &cat frog
+```
+
+## Merge with merge anchors
+Given a sample.yml file of:
+```yaml
+foo: &foo
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar: &bar
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: foobarList_b
+  !!merge <<:
+    - *foo
+    - *bar
+  c: foobarList_c
+foobar:
+  c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+```
+then
+```bash
+yq eval '.foobar * .foobarList' sample.yml
+```
+will output
+```yaml
+c: foobarList_c
+<<:
+  - *foo
+  - *bar
+thing: foobar_thing
+b: foobarList_b
+```
+

pkg/yqlib/doc/Multiply.md

@@ -1,204 +0,0 @@
-Like the multiple operator in `jq`, depending on the operands, this multiply operator will do different things. Currently only objects are supported, which have the effect of merging the RHS into the LHS.
-
-Upcoming versions of `yq` will add support for other types of multiplication (numbers, strings).
-
-Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
-
-## Merging files
-Note the use of eval-all to ensure all documents are loaded into memory.
-
-```bash
-yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
-```
-
-## Merge objects together, returning merged result only
-Given a sample.yml file of:
-```yaml
-a:
-  field: me
-  fieldA: cat
-b:
-  field:
-    g: wizz
-  fieldB: dog
-```
-then
-```bash
-yq eval '.a * .b' sample.yml
-```
-will output
-```yaml
-field:
-  g: wizz
-fieldA: cat
-fieldB: dog
-```
-
-## Merge objects together, returning parent object
-Given a sample.yml file of:
-```yaml
-a:
-  field: me
-  fieldA: cat
-b:
-  field:
-    g: wizz
-  fieldB: dog
-```
-then
-```bash
-yq eval '. * {"a":.b}' sample.yml
-```
-will output
-```yaml
-a:
-  field:
-    g: wizz
-  fieldA: cat
-  fieldB: dog
-b:
-  field:
-    g: wizz
-  fieldB: dog
-```
-
-## Merge keeps style of LHS
-Given a sample.yml file of:
-```yaml
-a: {things: great}
-b:
-  also: "me"
-
-```
-then
-```bash
-yq eval '. * {"a":.b}' sample.yml
-```
-will output
-```yaml
-a: {things: great, also: "me"}
-b:
-  also: "me"
-```
-
-## Merge arrays
-Given a sample.yml file of:
-```yaml
-a:
-  - 1
-  - 2
-  - 3
-b:
-  - 3
-  - 4
-  - 5
-```
-then
-```bash
-yq eval '. * {"a":.b}' sample.yml
-```
-will output
-```yaml
-a:
-  - 3
-  - 4
-  - 5
-b:
-  - 3
-  - 4
-  - 5
-```
-
-## Merge to prefix an element
-Given a sample.yml file of:
-```yaml
-a: cat
-b: dog
-```
-then
-```bash
-yq eval '. * {"a": {"c": .a}}' sample.yml
-```
-will output
-```yaml
-a:
-  c: cat
-b: dog
-```
-
-## Merge with simple aliases
-Given a sample.yml file of:
-```yaml
-a: &cat
-  c: frog
-b:
-  f: *cat
-c:
-  g: thongs
-```
-then
-```bash
-yq eval '.c * .b' sample.yml
-```
-will output
-```yaml
-g: thongs
-f: *cat
-```
-
-## Merge does not copy anchor names
-Given a sample.yml file of:
-```yaml
-a:
-  c: &cat frog
-b:
-  f: *cat
-c:
-  g: thongs
-```
-then
-```bash
-yq eval '.c * .a' sample.yml
-```
-will output
-```yaml
-g: thongs
-c: frog
-```
-
-## Merge with merge anchors
-Given a sample.yml file of:
-```yaml
-foo: &foo
-  a: foo_a
-  thing: foo_thing
-  c: foo_c
-bar: &bar
-  b: bar_b
-  thing: bar_thing
-  c: bar_c
-foobarList:
-  b: foobarList_b
-  !!merge <<:
-    - *foo
-    - *bar
-  c: foobarList_c
-foobar:
-  c: foobar_c
-  !!merge <<: *foo
-  thing: foobar_thing
-```
-then
-```bash
-yq eval '.foobar * .foobarList' sample.yml
-```
-will output
-```yaml
-c: foobarList_c
-<<:
-  - *foo
-  - *bar
-thing: foobar_thing
-b: foobarList_b
-```
-

pkg/yqlib/doc/Path.md

@@ -1,4 +1,7 @@
 The path operator can be used to get the traversal paths of matching nodes in an expression. The path is returned as an array, which if traversed in order will lead to the matching node.
+
+You can get the key/index of matching nodes by using the `path` operator to return the path array then piping that through `.[-1]` to get the last element of that array, the key.
+
 ## Map path
 Given a sample.yml file of:
 ```yaml
@@ -15,6 +18,21 @@ will output
 - b
 ```
 
+## Get map key
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a.b | path | .[-1]' sample.yml
+```
+will output
+```yaml
+b
+```
+
 ## Array path
 Given a sample.yml file of:
 ```yaml
@@ -32,6 +50,22 @@ will output
 - 1
 ```
 
+## Get array index
+Given a sample.yml file of:
+```yaml
+a:
+  - cat
+  - dog
+```
+then
+```bash
+yq eval '.a.[] | select(. == "dog") | path | .[-1]' sample.yml
+```
+will output
+```yaml
+1
+```
+
 ## Print path and value
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/doc/Pipe.md

@@ -0,0 +1,35 @@
+Pipe the results of an expression into another. Like the bash operator.
+
+## Simple Pipe
+Given a sample.yml file of:
+```yaml
+a:
+  b: cat
+```
+then
+```bash
+yq eval '.a | .b' sample.yml
+```
+will output
+```yaml
+cat
+```
+
+## Multiple updates
+Given a sample.yml file of:
+```yaml
+a: cow
+b: sheep
+c: same
+```
+then
+```bash
+yq eval '.a = "cat" | .b = "dog"' sample.yml
+```
+will output
+```yaml
+a: cat
+b: dog
+c: same
+```
+

pkg/yqlib/doc/Recursive Descent (Glob).md

@@ -0,0 +1,154 @@
+This operator recursively matches (or globs) 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
+```
+
+## Recursively find nodes with keys
+Note that this example has wrapped the expression in `[]` to show that there are two matches returned. You do not have to wrap in `[]` in your path expression.
+
+Given a sample.yml file of:
+```yaml
+a:
+  name: frog
+  b:
+    name: blog
+    age: 12
+```
+then
+```bash
+yq eval '[.. | select(has("name"))]' sample.yml
+```
+will output
+```yaml
+- name: frog
+  b:
+    name: blog
+    age: 12
+- name: blog
+  age: 12
+```
+
+## Recursively find nodes with values
+Given a sample.yml file of:
+```yaml
+a:
+  nameA: frog
+  b:
+    nameB: frog
+    age: 12
+```
+then
+```bash
+yq eval '.. | select(. == "frog")' sample.yml
+```
+will output
+```yaml
+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
+a: &cat
+  c: frog
+b: *cat
+```
+then
+```bash
+yq eval '[..]' sample.yml
+```
+will output
+```yaml
+- a: &cat
+    c: frog
+  b: *cat
+- &cat
+  c: frog
+- frog
+- *cat
+```
+
+## Merge docs are not traversed
+Given a sample.yml file of:
+```yaml
+foo: &foo
+  a: foo_a
+  thing: foo_thing
+  c: foo_c
+bar: &bar
+  b: bar_b
+  thing: bar_thing
+  c: bar_c
+foobarList:
+  b: foobarList_b
+  !!merge <<:
+    - *foo
+    - *bar
+  c: foobarList_c
+foobar:
+  c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+```
+then
+```bash
+yq eval '.foobar | [..]' sample.yml
+```
+will output
+```yaml
+- c: foobar_c
+  !!merge <<: *foo
+  thing: foobar_thing
+- foobar_c
+- *foo
+- foobar_thing
+```
+

pkg/yqlib/doc/Recursive Descent.md

@@ -1,63 +0,0 @@
-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:
-
-```bash
-yq eval '.. style= "flow"' file.yaml
-```
-## Aliases are not traversed
-Given a sample.yml file of:
-```yaml
-a: &cat
-  c: frog
-b: *cat
-```
-then
-```bash
-yq eval '[..]' sample.yml
-```
-will output
-```yaml
-- a: &cat
-    c: frog
-  b: *cat
-- &cat
-  c: frog
-- frog
-- *cat
-```
-
-## Merge docs are not traversed
-Given a sample.yml file of:
-```yaml
-foo: &foo
-  a: foo_a
-  thing: foo_thing
-  c: foo_c
-bar: &bar
-  b: bar_b
-  thing: bar_thing
-  c: bar_c
-foobarList:
-  b: foobarList_b
-  !!merge <<:
-    - *foo
-    - *bar
-  c: foobarList_c
-foobar:
-  c: foobar_c
-  !!merge <<: *foo
-  thing: foobar_thing
-```
-then
-```bash
-yq eval '.foobar | [..]' sample.yml
-```
-will output
-```yaml
-- c: foobar_c
-  !!merge <<: *foo
-  thing: foobar_thing
-- foobar_c
-- *foo
-- foobar_thing
-```
-

pkg/yqlib/doc/Reduce.md

@@ -0,0 +1,76 @@
+Reduce is a powerful way to process a collection of data into a new form.
+
+```
+<exp> as $<name> ireduce (<init>; <block>)
+```
+
+e.g.
+
+```
+.[] as $item ireduce (0; . + $item)
+```
+
+On the LHS we are configuring the collection of items that will be reduced `<exp>` as well as what each element will be called `$<name>`. Note that the array has been splatted into its individual elements.
+
+On the RHS there is `<init>`, the starting value of the accumulator and `<block>`, the expression that will update the accumulator for each element in the collection. Note that within the block expression, `.` will evaluate to the current value of the accumulator. 
+
+## yq vs jq syntax
+Reduce syntax in `yq` is a little different from `jq` - as `yq` (currently) isn't as sophisticated as `jq` and its only supports infix notation (e.g. a + b, where the operator is in the middle of the two parameters) - where as `jq` uses a mix of infix notation with _prefix_ notation (e.g. `reduce a b` is like writing `+ a b`).
+
+To that end, the reduce operator is called `ireduce` for backwards compatability if a `jq` like prefix version of `reduce` is ever added.
+
+
+## Sum numbers
+Given a sample.yml file of:
+```yaml
+- 10
+- 2
+- 5
+- 3
+```
+then
+```bash
+yq eval '.[] as $item ireduce (0; . + $item)' sample.yml
+```
+will output
+```yaml
+20
+```
+
+## Merge all yaml files together
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+And another sample another.yml file of:
+```yaml
+b: dog
+```
+then
+```bash
+yq eval-all '. as $item ireduce ({}; . * $item )' sample.yml another.yml
+```
+will output
+```yaml
+a: cat
+b: dog
+```
+
+## Convert an array to an object
+Given a sample.yml file of:
+```yaml
+- name: Cathy
+  has: apples
+- name: Bob
+  has: bananas
+```
+then
+```bash
+yq eval '.[] as $item ireduce ({}; .[$item | .name] = ($item | .has) )' sample.yml
+```
+will output
+```yaml
+Cathy: apples
+Bob: bananas
+```
+

pkg/yqlib/doc/Sort Keys.md

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

pkg/yqlib/doc/Split into Documents.md

@@ -0,0 +1,31 @@
+# Split into Documents
+
+This operator splits all matches into separate documents
+
+## Split empty
+Running
+```bash
+yq eval --null-input 'splitDoc'
+```
+will output
+```yaml
+
+```
+
+## Split array
+Given a sample.yml file of:
+```yaml
+- a: cat
+- b: dog
+```
+then
+```bash
+yq eval '.[] | splitDoc' sample.yml
+```
+will output
+```yaml
+a: cat
+---
+b: dog
+```
+

pkg/yqlib/doc/String Operators.md

@@ -0,0 +1,88 @@
+# String Operators
+
+## Join strings
+Given a sample.yml file of:
+```yaml
+- cat
+- meow
+- 1
+- null
+- true
+```
+then
+```bash
+yq eval 'join("; ")' sample.yml
+```
+will output
+```yaml
+cat; meow; 1; ; true
+```
+
+## Substitute / Replace string
+This uses golang regex, described [here](https://github.com/google/re2/wiki/Syntax)
+Note the use of `|=` to run in context of the current string value.
+
+Given a sample.yml file of:
+```yaml
+a: dogs are great
+```
+then
+```bash
+yq eval '.a |= sub("dogs", "cats")' sample.yml
+```
+will output
+```yaml
+a: cats are great
+```
+
+## Substitute / Replace string with regex
+This uses golang regex, described [here](https://github.com/google/re2/wiki/Syntax)
+Note the use of `|=` to run in context of the current string value.
+
+Given a sample.yml file of:
+```yaml
+a: cat
+b: heat
+```
+then
+```bash
+yq eval '.[] |= sub("(a)", "${1}r")' sample.yml
+```
+will output
+```yaml
+a: cart
+b: heart
+```
+
+## Split strings
+Given a sample.yml file of:
+```yaml
+cat; meow; 1; ; true
+```
+then
+```bash
+yq eval 'split("; ")' sample.yml
+```
+will output
+```yaml
+- cat
+- meow
+- "1"
+- ""
+- "true"
+```
+
+## Split strings one match
+Given a sample.yml file of:
+```yaml
+word
+```
+then
+```bash
+yq eval 'split("; ")' sample.yml
+```
+will output
+```yaml
+- word
+```
+

pkg/yqlib/doc/Style.md

@@ -1,4 +1,42 @@
 The style operator can be used to get or set the style of nodes (e.g. string style, yaml style)
+## Update and set style of a particular node (simple)
+Given a sample.yml file of:
+```yaml
+a:
+  b: thing
+  c: something
+```
+then
+```bash
+yq eval '.a.b = "new" | .a.b style="double"' sample.yml
+```
+will output
+```yaml
+a:
+  b: "new"
+  c: something
+```
+
+## Update and set style of a particular node using path variables
+You can use a variable to re-use a path
+
+Given a sample.yml file of:
+```yaml
+a:
+  b: thing
+  c: something
+```
+then
+```bash
+yq eval '.a.b as $x | $x = "new" | $x style="double"' sample.yml
+```
+will output
+```yaml
+a:
+  b: "new"
+  c: something
+```
+
 ## Set tagged style
 Given a sample.yml file of:
 ```yaml
@@ -40,6 +78,26 @@ 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 +183,19 @@ 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 +205,22 @@ 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/Subtract.md

@@ -0,0 +1,71 @@
+
+## Number subtraction - float
+If the lhs or rhs are floats then the expression will be calculated with floats.
+
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4.5
+```
+then
+```bash
+yq eval '.a = .a - .b' sample.yml
+```
+will output
+```yaml
+a: -1.5
+b: 4.5
+```
+
+## Number subtraction - float
+If the lhs or rhs are floats then the expression will be calculated with floats.
+
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4.5
+```
+then
+```bash
+yq eval '.a = .a - .b' sample.yml
+```
+will output
+```yaml
+a: -1.5
+b: 4.5
+```
+
+## Number subtraction - int
+If both the lhs and rhs are ints then the expression will be calculated with ints.
+
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 4
+```
+then
+```bash
+yq eval '.a = .a - .b' sample.yml
+```
+will output
+```yaml
+a: -1
+b: 4
+```
+
+## Decrement numbers
+Given a sample.yml file of:
+```yaml
+a: 3
+b: 5
+```
+then
+```bash
+yq eval '.[] -= 1' sample.yml
+```
+will output
+```yaml
+a: 2
+b: 4
+```
+

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 (Read).md

@@ -32,8 +32,23 @@ b: apple
 c: banana
 ```
 
+## Optional Splat
+Just like splat, but won't error if you run it against scalars
+
+Given a sample.yml file of:
+```yaml
+cat
+```
+then
+```bash
+yq eval '.[]' sample.yml
+```
+will output
+```yaml
+```
+
 ## Special characters
-Use quotes around path elements with special characters
+Use quotes with brackets around path elements with special characters
 
 Given a sample.yml file of:
 ```yaml
@@ -41,13 +56,47 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '."{}"' sample.yml
+yq eval '.["{}"]' sample.yml
 ```
 will output
 ```yaml
 frog
 ```
 
+## Keys with spaces
+Use quotes with brackets around path elements with special characters
+
+Given a sample.yml file of:
+```yaml
+"red rabbit": frog
+```
+then
+```bash
+yq eval '.["red rabbit"]' sample.yml
+```
+will output
+```yaml
+frog
+```
+
+## Dynamic keys
+Expressions within [] can be used to dynamically lookup / calculate keys
+
+Given a sample.yml file of:
+```yaml
+b: apple
+apple: crispy yum
+banana: soft yum
+```
+then
+```bash
+yq eval '.[.b]' sample.yml
+```
+will output
+```yaml
+crispy yum
+```
+
 ## Children don't exist
 Nodes are added dynamically while traversing
 
@@ -64,6 +113,23 @@ will output
 null
 ```
 
+## Optional identifier
+Like jq, does not output an error when the yaml is not an array or object as expected
+
+Given a sample.yml file of:
+```yaml
+- 1
+- 2
+- 3
+```
+then
+```bash
+yq eval '.a?' sample.yml
+```
+will output
+```yaml
+```
+
 ## Wildcard matching
 Given a sample.yml file of:
 ```yaml
@@ -106,7 +172,7 @@ b: *cat
 ```
 then
 ```bash
-yq eval '.b.[]' sample.yml
+yq eval '.b[]' sample.yml
 ```
 will output
 ```yaml
@@ -138,7 +204,7 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '[0]' sample.yml
+yq eval '.[0]' sample.yml
 ```
 will output
 ```yaml
@@ -152,7 +218,7 @@ Given a sample.yml file of:
 ```
 then
 ```bash
-yq eval '[2]' sample.yml
+yq eval '.[2]' sample.yml
 ```
 will output
 ```yaml
@@ -166,7 +232,7 @@ a: b
 ```
 then
 ```bash
-yq eval '[0]' sample.yml
+yq eval '.[0]' sample.yml
 ```
 will output
 ```yaml
@@ -290,7 +356,7 @@ foobar:
 ```
 then
 ```bash
-yq eval '.foobar.[]' sample.yml
+yq eval '.foobar[]' sample.yml
 ```
 will output
 ```yaml
@@ -356,7 +422,7 @@ foobar:
 ```
 then
 ```bash
-yq eval '.foobarList.[]' sample.yml
+yq eval '.foobarList[]' sample.yml
 ```
 will output
 ```yaml
@@ -366,3 +432,21 @@ 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/Unique.md

@@ -0,0 +1,82 @@
+This is used to filter out duplicated items in an array.
+
+## Unique array of scalars (string/numbers)
+Given a sample.yml file of:
+```yaml
+- 1
+- 2
+- 3
+- 2
+```
+then
+```bash
+yq eval 'unique' sample.yml
+```
+will output
+```yaml
+- 1
+- 2
+- 3
+```
+
+## Unique nulls
+Unique works on the node value, so it considers different representations of nulls to be different
+
+Given a sample.yml file of:
+```yaml
+- ~
+- null
+- ~
+- null
+```
+then
+```bash
+yq eval 'unique' sample.yml
+```
+will output
+```yaml
+- ~
+- null
+```
+
+## Unique all nulls
+Run against the node tag to unique all the nulls
+
+Given a sample.yml file of:
+```yaml
+- ~
+- null
+- ~
+- null
+```
+then
+```bash
+yq eval 'unique_by(tag)' sample.yml
+```
+will output
+```yaml
+- ~
+```
+
+## Unique array object fields
+Given a sample.yml file of:
+```yaml
+- name: harry
+  pet: cat
+- name: billy
+  pet: dog
+- name: harry
+  pet: dog
+```
+then
+```bash
+yq eval 'unique_by(.name)' sample.yml
+```
+will output
+```yaml
+- name: harry
+  pet: cat
+- name: billy
+  pet: dog
+```
+

pkg/yqlib/doc/Variable Operators.md

@@ -0,0 +1,58 @@
+For more complex scenarios, variables can be used to hold values of expression to be used in other expressions.
+
+## Single value variable
+Given a sample.yml file of:
+```yaml
+a: cat
+```
+then
+```bash
+yq eval '.a as $foo | $foo' sample.yml
+```
+will output
+```yaml
+cat
+```
+
+## Multi value variable
+Given a sample.yml file of:
+```yaml
+- cat
+- dog
+```
+then
+```bash
+yq eval '.[] as $foo | $foo' sample.yml
+```
+will output
+```yaml
+cat
+dog
+```
+
+## Using variables as a lookup
+Example taken from [jq](https://stedolan.github.io/jq/manual/#Variable/SymbolicBindingOperator:...as$identifier|...)
+
+Given a sample.yml file of:
+```yaml
+"posts":
+  - "title": Frist psot
+    "author": anon
+  - "title": A well-written article
+    "author": person1
+"realnames":
+  "anon": Anonymous Coward
+  "person1": Person McPherson
+```
+then
+```bash
+yq eval '.realnames as $names | .posts[] | {"title":.title, "author": $names[.author]}' sample.yml
+```
+will output
+```yaml
+title: Frist psot
+author: Anonymous Coward
+title: A well-written article
+author: Person McPherson
+```
+

pkg/yqlib/doc/aa.md

@@ -0,0 +1,116 @@
+# Operators
+
+In `yq` expressions are made up of operators and pipes. A context of nodes is passed through the expression and each operation takes the context as input and returns a new context as output. That output is piped in as input for the next operation in the expression. To begin with, the context is set to the first yaml document of the first yaml file (if processing in sequence using eval).
+
+Lets look at a couple of examples.
+
+## Example with a simple operator
+
+Given a document like:
+
+```yaml
+- [a]
+- "cat"
+```
+
+with an expression:
+
+```
+.[] | length
+```
+
+`yq` will initially set the context as single node of the entire yaml document, an array of two elements.
+
+```yaml
+- [a]
+- "cat"
+```
+
+This gets piped into the splat operator `.[]` which will split out the context into a collection of two nodes `[a]` and `"cat"`. Note that this is _not_ a yaml array.
+
+The `length` operator take no arguments, and will simply return the length of _each_ matching node in the context. So for the context of `[a]` and `"cat"`, it will return a new context of `1` and `3`.
+
+This being the last operation in the expression, the results will be printed out:
+
+```
+1
+3
+```
+
+# Example with an operator that takes arguments.
+
+Given a document like:
+
+```yaml
+a: cat
+b: dog
+```
+
+with an expression:
+
+```
+.a = .b
+```
+
+The `=` operator takes two arguments, a `lhs` expression, which in this case is `.a` and `rhs` expression which is `.b`. 
+
+It pipes the current, lets call it 'root' context through the `lhs` expression of `.a` to return the node 
+
+```yaml
+cat
+```
+
+Note that this node holds not only its value 'cat', but comments and metadata too, including path and parent information.
+
+The `=` operator then pipes the 'root' context through the `rhs` expression of `.b` to return the node
+
+```yaml
+dog
+```
+
+Both sides have now been evaluated, so now the operator copies across the value from the RHS to the value on the LHS, and it returns the now updated context:
+
+```yaml
+a: dog
+b: dog
+```
+
+# Relative update (e.g. `|=`)
+There is another form of the `=` operator which we call the relative form. It's very similar to `=` but with one key difference when evaluating the RHS expression.
+
+In the plain form, we pass in the 'root' level context to the RHS expression. In relative form, we pass in _each result of the LHS_ to the RHS expression. Let's go through an example.
+
+Given a document like:
+
+```yaml
+a: 1
+b: thing
+```
+
+with an expression:
+
+```
+.a |= . + 1
+```
+
+Similar to the `=` operator, `|=` takes two operands, the LHS and RHS.
+
+It pipes the current context (the whole document) through the LHS expression  of `.a` to get the node value:
+
+```
+1
+```
+
+Now it pipes _that LHS context_ into the RHS expression `. + 1` (whereas in the `=` plain form it piped the original document context into the RHS) to yield:
+
+
+```
+2
+```
+
+The assignment operator then copies across the value from the RHS to the value on the LHS, and it returns the now updated 'root' context:
+
+```yaml
+a: 2
+b: thing
+```

pkg/yqlib/doc/headers/Add.md

@@ -1,4 +1,6 @@
 Add behaves differently according to the type of the LHS:
 - arrays: concatenate
-- number scalars: arithmetic addition (soon)
-- string scalars: concatenate (soon)
+- number scalars: arithmetic addition
+- string scalars: concatenate
+
+Use `+=` as append assign for things like increment. Note that `.a += .x` is equivalent to running `.a = .a + .x`.

pkg/yqlib/doc/headers/Alternative (Default value).md

@@ -0,0 +1 @@
+This operator is used to provide alternative (or default) values when a particular expression is either null or false.

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

@@ -0,0 +1,4 @@
+Use the `alias` and `anchor` operators to read and write yaml aliases and anchors. The `explode` operator normalises a yaml file (dereference (or expands) aliases and remove anchor names).
+
+`yq` supports merge aliases (like `<<: *blah`) however this is no longer in the standard yaml spec (1.2) and so `yq` will automatically add the `!!merge` tag to these nodes as it is effectively a custom tag.
+

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

@@ -1 +1,9 @@
-The `or` and `and` operators take two parameters and return a boolean result. `not` flips a boolean from true to false, or vice versa. These are most commonly used with the `select` operator to filter particular nodes.
+The `or` and `and` operators take two parameters and return a boolean result. 
+
+`not` flips a boolean from true to false, or vice versa. 
+
+`any` will return `true` if there are any `true` values in a array sequence, and `all` will return true if _all_ elements in an array are true.
+
+`any_c(condition)` and `all_c(condition)` are like `any` and `all` but they take a condition expression that is used against each element to determine if it's `true`. Note: in `jq` you can simply pass a condition to `any` or `all` and it simply works - `yq` isn't that clever..yet
+
+These are most commonly used with the `select` operator to filter particular nodes.

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

@@ -1 +1,11 @@
 Use these comment operators to set or retrieve comments.
+
+Like the `=` and `|=` assign operators, the same syntax applies when updating comments:
+
+
+### plain form: `=`
+This will assign the LHS nodes comments to the expression on the RHS. The RHS is run against the matching nodes in the pipeline
+
+### relative form: `|=` 
+Similar to the plain form, however the RHS evaluates against each matching LHS node! This is useful if you want to set the comments as a relative expression of the node, for instance its value or path.
+

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

@@ -1 +1 @@
-Use the `documentIndex` operator to select nodes of a particular document.
+Use the `documentIndex` operator (or the `di` shorthand) to select nodes of a particular document.

pkg/yqlib/doc/headers/Entries.md

@@ -0,0 +1 @@
+Similar to the same named functions in `jq` these functions convert to/from an object and an array of key-value pairs. This is most useful for performing operations on keys of maps.

pkg/yqlib/doc/headers/Env Variable Operators.md

@@ -0,0 +1,2 @@
+This operator is used to handle environment variables usage in path expressions. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. Note that there are two forms, `env` which will parse the environment variable as a yaml (be it a map, array, string, number of boolean) and `strenv` which will always parse the argument as a string.
+

pkg/yqlib/doc/headers/Explode.md

@@ -1 +0,0 @@
-Explodes (or dereferences) aliases and anchors.

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/Keys.md

@@ -0,0 +1,3 @@
+# Keys
+
+Use the `keys` operator to return map keys or array indices. 

pkg/yqlib/doc/headers/Length.md

@@ -0,0 +1 @@
+Returns the lengths of the nodes. Length is defined according to the type of the node.

pkg/yqlib/doc/headers/Multiply (Merge).md

@@ -0,0 +1,20 @@
+Like the multiple operator in jq, depending on the operands, this multiply operator will do different things. Currently numbers, arrays and objects are supported.
+
+## Objects and arrays - merging
+Objects are merged deeply matching on matching keys. By default, array values override and are not deeply merged.
+
+Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
+
+### Merge Flags
+You can control how objects are merged by using one or more of the following flags. Multiple flags can be used together, e.g. `.a *+? .b`.  See examples below
+
+- `+` to append arrays
+- `?` to only merge existing fields
+- `d` to deeply merge arrays
+
+### Merging files
+Note the use of `eval-all` to ensure all documents are loaded into memory.
+
+```bash
+yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
+```

pkg/yqlib/doc/headers/Multiply.md

@@ -1,12 +0,0 @@
-Like the multiple operator in `jq`, depending on the operands, this multiply operator will do different things. Currently only objects are supported, which have the effect of merging the RHS into the LHS.
-
-Upcoming versions of `yq` will add support for other types of multiplication (numbers, strings).
-
-Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.
-
-## Merging files
-Note the use of eval-all to ensure all documents are loaded into memory.
-
-```bash
-yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
-```

pkg/yqlib/doc/headers/Path.md

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

pkg/yqlib/doc/headers/Pipe.md

@@ -0,0 +1 @@
+Pipe the results of an expression into another. Like the bash operator.

pkg/yqlib/doc/headers/Recursive Descent (Glob).md

@@ -0,0 +1,19 @@
+This operator recursively matches (or globs) 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/doc/headers/Recursive Descent.md

@@ -1,5 +0,0 @@
-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:
-
-```bash
-yq eval '.. style= "flow"' file.yaml
-```

pkg/yqlib/doc/headers/Reduce.md

@@ -0,0 +1,21 @@
+Reduce is a powerful way to process a collection of data into a new form.
+
+```
+<exp> as $<name> ireduce (<init>; <block>)
+```
+
+e.g.
+
+```
+.[] as $item ireduce (0; . + $item)
+```
+
+On the LHS we are configuring the collection of items that will be reduced `<exp>` as well as what each element will be called `$<name>`. Note that the array has been splatted into its individual elements.
+
+On the RHS there is `<init>`, the starting value of the accumulator and `<block>`, the expression that will update the accumulator for each element in the collection. Note that within the block expression, `.` will evaluate to the current value of the accumulator. 
+
+## yq vs jq syntax
+Reduce syntax in `yq` is a little different from `jq` - as `yq` (currently) isn't as sophisticated as `jq` and its only supports infix notation (e.g. a + b, where the operator is in the middle of the two parameters) - where as `jq` uses a mix of infix notation with _prefix_ notation (e.g. `reduce a b` is like writing `+ a b`).
+
+To that end, the reduce operator is called `ireduce` for backwards compatability if a `jq` like prefix version of `reduce` is ever added.
+

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

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

pkg/yqlib/doc/headers/Split into Documents.md

@@ -0,0 +1,3 @@
+# Split into Documents
+
+This operator splits all matches into separate documents

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

@@ -0,0 +1 @@
+# String Operators

pkg/yqlib/doc/headers/Unique.md

@@ -0,0 +1 @@
+This is used to filter out duplicated items in an array.

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

@@ -0,0 +1 @@
+For more complex scenarios, variables can be used to hold values of expression to be used in other expressions.

pkg/yqlib/encoder.go

@@ -50,7 +50,7 @@ func (ye *yamlEncoder) Encode(node *yaml.Node) error {
 	}
 
 	if ye.colorise {
-		return ColorizeAndPrint(tempBuffer.Bytes(), ye.destination)
+		return colorizeAndPrint(tempBuffer.Bytes(), ye.destination)
 	}
 	return nil
 }
@@ -76,6 +76,8 @@ func mapKeysToStrings(node *yaml.Node) {
 
 func NewJsonEncoder(destination io.Writer, indent int) Encoder {
 	var encoder = json.NewEncoder(destination)
+	encoder.SetEscapeHTML(false) // do not escape html chars e.g. &, <, >
+
 	var indentString = ""
 
 	for index := 0; index < indent; index++ {
@@ -153,11 +155,15 @@ func (o *orderedMap) UnmarshalJSON(data []byte) error {
 }
 
 func (o orderedMap) MarshalJSON() ([]byte, error) {
-	if o.kv == nil {
-		return json.Marshal(o.altVal)
-	}
 	buf := new(bytes.Buffer)
 	enc := json.NewEncoder(buf)
+	enc.SetEscapeHTML(false) // do not escape html chars e.g. &, <, >
+	if o.kv == nil {
+		if err := enc.Encode(o.altVal); err != nil {
+			return nil, err
+		}
+		return buf.Bytes(), nil
+	}
 	buf.WriteByte('{')
 	for idx, el := range o.kv {
 		if err := enc.Encode(el.K); err != nil {

pkg/yqlib/encoder_test.go

@@ -9,29 +9,11 @@ import (
 	"github.com/mikefarah/yq/v4/test"
 )
 
-var sampleYaml = `zabbix: winner
-apple: great
-banana:
-- {cobra: kai, angus: bob}
-`
-
-var expectedJson = `{
-  "zabbix": "winner",
-  "apple": "great",
-  "banana": [
-    {
-      "cobra": "kai",
-      "angus": "bob"
-    }
-  ]
-}
-`
-
-func TestJsonEncoderPreservesObjectOrder(t *testing.T) {
+func yamlToJson(sampleYaml string, indent int) string {
 	var output bytes.Buffer
 	writer := bufio.NewWriter(&output)
 
-	var jsonEncoder = NewJsonEncoder(writer, 2)
+	var jsonEncoder = NewJsonEncoder(writer, indent)
 	inputs, err := readDocuments(strings.NewReader(sampleYaml), "sample.yml", 0)
 	if err != nil {
 		panic(err)
@@ -42,6 +24,33 @@ func TestJsonEncoderPreservesObjectOrder(t *testing.T) {
 		panic(err)
 	}
 	writer.Flush()
-	test.AssertResult(t, expectedJson, output.String())
 
+	return strings.TrimSuffix(output.String(), "\n")
+}
+
+func TestJsonEncoderPreservesObjectOrder(t *testing.T) {
+	var sampleYaml = `zabbix: winner
+apple: great
+banana:
+- {cobra: kai, angus: bob}
+`
+	var expectedJson = `{
+  "zabbix": "winner",
+  "apple": "great",
+  "banana": [
+    {
+      "cobra": "kai",
+      "angus": "bob"
+    }
+  ]
+}`
+	var actualJson = yamlToJson(sampleYaml, 2)
+	test.AssertResult(t, expectedJson, actualJson)
+}
+
+func TestJsonEncoderDoesNotEscapeHTMLChars(t *testing.T) {
+	var sampleYaml = `build: "( ./lint && ./format && ./compile ) < src.code"`
+	var expectedJson = `{"build":"( ./lint && ./format && ./compile ) < src.code"}`
+	var actualJson = yamlToJson(sampleYaml, 0)
+	test.AssertResult(t, expectedJson, actualJson)
 }

pkg/yqlib/expression_parser.go

@@ -0,0 +1,75 @@
+package yqlib
+
+import (
+	"fmt"
+	"strings"
+)
+
+type ExpressionNode struct {
+	Operation *Operation
+	Lhs       *ExpressionNode
+	Rhs       *ExpressionNode
+}
+
+type ExpressionParser interface {
+	ParseExpression(expression string) (*ExpressionNode, error)
+}
+
+type expressionParserImpl struct {
+	pathTokeniser expressionTokeniser
+	pathPostFixer expressionPostFixer
+}
+
+func NewExpressionParser() ExpressionParser {
+	return &expressionParserImpl{newExpressionTokeniser(), newExpressionPostFixer()}
+}
+
+func (p *expressionParserImpl) ParseExpression(expression string) (*ExpressionNode, error) {
+	tokens, err := p.pathTokeniser.Tokenise(expression)
+	if err != nil {
+		return nil, err
+	}
+	var Operations []*Operation
+	Operations, err = p.pathPostFixer.ConvertToPostfix(tokens)
+	if err != nil {
+		return nil, err
+	}
+	return p.createExpressionTree(Operations)
+}
+
+func (p *expressionParserImpl) createExpressionTree(postFixPath []*Operation) (*ExpressionNode, error) {
+	var stack = make([]*ExpressionNode, 0)
+
+	if len(postFixPath) == 0 {
+		return nil, nil
+	}
+
+	for _, Operation := range postFixPath {
+		var newNode = ExpressionNode{Operation: Operation}
+		log.Debugf("pathTree %v ", Operation.toString())
+		if Operation.OperationType.NumArgs > 0 {
+			numArgs := Operation.OperationType.NumArgs
+			if numArgs == 1 {
+				if len(stack) < 1 {
+					return nil, fmt.Errorf("'%v' expects 1 arg but received none", strings.TrimSpace(Operation.StringValue))
+				}
+				remaining, rhs := stack[:len(stack)-1], stack[len(stack)-1]
+				newNode.Rhs = rhs
+				stack = remaining
+			} else if numArgs == 2 {
+				if len(stack) < 2 {
+					return nil, fmt.Errorf("'%v' expects 2 args but there is %v", strings.TrimSpace(Operation.StringValue), len(stack))
+				}
+				remaining, lhs, rhs := stack[:len(stack)-2], stack[len(stack)-2], stack[len(stack)-1]
+				newNode.Lhs = lhs
+				newNode.Rhs = rhs
+				stack = remaining
+			}
+		}
+		stack = append(stack, &newNode)
+	}
+	if len(stack) != 1 {
+		return nil, fmt.Errorf("Bad expression, please check expression syntax")
+	}
+	return stack[0], nil
+}

pkg/yqlib/expression_parser_test.go

@@ -0,0 +1,42 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+func TestPathTreeNoArgsForTwoArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression("=")
+	test.AssertResultComplex(t, "'=' expects 2 args but there is 0", err.Error())
+}
+
+func TestPathTreeOneLhsArgsForTwoArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression(".a =")
+	test.AssertResultComplex(t, "'=' expects 2 args but there is 1", err.Error())
+}
+
+func TestPathTreeOneRhsArgsForTwoArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression("= .a")
+	test.AssertResultComplex(t, "'=' expects 2 args but there is 1", err.Error())
+}
+
+func TestPathTreeTwoArgsForTwoArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression(".a = .b")
+	test.AssertResultComplex(t, nil, err)
+}
+
+func TestPathTreeNoArgsForOneArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression("explode")
+	test.AssertResultComplex(t, "'explode' expects 1 arg but received none", err.Error())
+}
+
+func TestPathTreeOneArgForOneArgOp(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression("explode(.)")
+	test.AssertResultComplex(t, nil, err)
+}
+
+func TestPathTreeExtraArgs(t *testing.T) {
+	_, err := NewExpressionParser().ParseExpression("sortKeys(.) explode(.)")
+	test.AssertResultComplex(t, "Bad expression, please check expression syntax", err.Error())
+}

pkg/yqlib/expression_postfix.go

@@ -0,0 +1,109 @@
+package yqlib
+
+import (
+	"errors"
+
+	logging "gopkg.in/op/go-logging.v1"
+)
+
+type expressionPostFixer interface {
+	ConvertToPostfix([]*token) ([]*Operation, error)
+}
+
+type expressionPostFixerImpl struct {
+}
+
+func newExpressionPostFixer() expressionPostFixer {
+	return &expressionPostFixerImpl{}
+}
+
+func popOpToResult(opStack []*token, result []*Operation) ([]*token, []*Operation) {
+	var newOp *token
+	opStack, newOp = opStack[0:len(opStack)-1], opStack[len(opStack)-1]
+	log.Debugf("popped %v from opstack to results", newOp.toString(true))
+	return opStack, append(result, newOp.Operation)
+}
+
+func (p *expressionPostFixerImpl) ConvertToPostfix(infixTokens []*token) ([]*Operation, error) {
+	var result []*Operation
+	// surround the whole thing with brackets
+	var opStack = []*token{{TokenType: openBracket}}
+	var tokens = append(infixTokens, &token{TokenType: closeBracket})
+
+	for _, currentToken := range tokens {
+		log.Debugf("postfix processing currentToken %v", currentToken.toString(true))
+		switch currentToken.TokenType {
+		case openBracket, openCollect, openCollectObject:
+			opStack = append(opStack, currentToken)
+			log.Debugf("put %v onto the opstack", currentToken.toString(true))
+		case closeCollect, closeCollectObject:
+			var opener tokenType = openCollect
+			var collectOperator *operationType = collectOpType
+			if currentToken.TokenType == closeCollectObject {
+				opener = openCollectObject
+				collectOperator = collectObjectOpType
+			}
+
+			for len(opStack) > 0 && opStack[len(opStack)-1].TokenType != opener {
+				opStack, result = popOpToResult(opStack, result)
+			}
+			if len(opStack) == 0 {
+				return nil, errors.New("Bad path expression, got close collect brackets without matching opening bracket")
+			}
+			// now we should have [ as the last element on the opStack, get rid of it
+			opStack = opStack[0 : len(opStack)-1]
+			log.Debugf("deleteing open bracket from opstack")
+
+			//and append a collect to the result
+			// hack - see if there's the optional traverse flag
+			// on the close op - move it to the collect op.
+			// allows for .["cat"]?
+			prefs := traversePreferences{}
+			closeTokenMatch := string(currentToken.Match.Bytes)
+			if closeTokenMatch[len(closeTokenMatch)-1:] == "?" {
+				prefs.OptionalTraverse = true
+			}
+			result = append(result, &Operation{OperationType: collectOperator, Preferences: prefs})
+			log.Debugf("put collect onto the result")
+			result = append(result, &Operation{OperationType: shortPipeOpType})
+			log.Debugf("put shortpipe onto the result")
+
+			//traverseArrayCollect is a sneaky op that needs to be included too
+			//when closing a []
+			if len(opStack) > 0 && opStack[len(opStack)-1].Operation != nil && opStack[len(opStack)-1].Operation.OperationType == traverseArrayOpType {
+				opStack, result = popOpToResult(opStack, result)
+			}
+
+		case closeBracket:
+			for len(opStack) > 0 && opStack[len(opStack)-1].TokenType != openBracket {
+				opStack, result = popOpToResult(opStack, result)
+			}
+			if len(opStack) == 0 {
+				return nil, errors.New("Bad path expression, got close brackets without matching opening bracket")
+			}
+			// now we should have ( as the last element on the opStack, get rid of it
+			opStack = opStack[0 : len(opStack)-1]
+
+		default:
+			var currentPrecedence = currentToken.Operation.OperationType.Precedence
+			// pop off higher precedent operators onto the result
+			for len(opStack) > 0 &&
+				opStack[len(opStack)-1].TokenType == operationToken &&
+				opStack[len(opStack)-1].Operation.OperationType.Precedence > currentPrecedence {
+				opStack, result = popOpToResult(opStack, result)
+			}
+			// add this operator to the opStack
+			opStack = append(opStack, currentToken)
+			log.Debugf("put %v onto the opstack", currentToken.toString(true))
+		}
+	}
+
+	if log.IsEnabledFor(logging.DEBUG) {
+		log.Debugf("PostFix Result:")
+		for _, currentToken := range result {
+			log.Debugf("> %v", currentToken.toString())
+		}
+	}
+
+	return result, nil
+}

pkg/yqlib/expression_processing_test.go

@@ -0,0 +1,276 @@
+package yqlib
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+var pathTests = []struct {
+	path            string
+	expectedTokens  []interface{}
+	expectedPostFix []interface{}
+}{
+	{
+		`.[0]`,
+		append(make([]interface{}, 0), "SELF", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "SELF", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.[0][1]`,
+		append(make([]interface{}, 0), "SELF", "TRAVERSE_ARRAY", "[", "0 (int64)", "]", "TRAVERSE_ARRAY", "[", "1 (int64)", "]"),
+		append(make([]interface{}, 0), "SELF", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "1 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`"\""`,
+		append(make([]interface{}, 0), "\" (string)"),
+		append(make([]interface{}, 0), "\" (string)"),
+	},
+	{
+		`[]|join(".")`,
+		append(make([]interface{}, 0), "[", "EMPTY", "]", "PIPE", "JOIN", "(", ". (string)", ")"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE", ". (string)", "JOIN", "PIPE"),
+	},
+	{
+		`{"cool": .b or .c}`,
+		append(make([]interface{}, 0), "{", "cool (string)", "CREATE_MAP", "b", "OR", "c", "}"),
+		append(make([]interface{}, 0), "cool (string)", "b", "c", "OR", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`{"cool": []|join(".")}`,
+		append(make([]interface{}, 0), "{", "cool (string)", "CREATE_MAP", "[", "EMPTY", "]", "PIPE", "JOIN", "(", ". (string)", ")", "}"),
+		append(make([]interface{}, 0), "cool (string)", "EMPTY", "COLLECT", "SHORT_PIPE", ". (string)", "JOIN", "PIPE", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`.a as $item ireduce (0; . + $item)`, // note - add code to shuffle reduce to this position for postfix
+		append(make([]interface{}, 0), "a", "ASSIGN_VARIABLE", "GET_VARIABLE", "REDUCE", "(", "0 (int64)", "BLOCK", "SELF", "ADD", "GET_VARIABLE", ")"),
+		append(make([]interface{}, 0), "a", "GET_VARIABLE", "ASSIGN_VARIABLE", "0 (int64)", "SELF", "GET_VARIABLE", "ADD", "BLOCK", "REDUCE"),
+	},
+	{
+		`.a | .b | .c`,
+		append(make([]interface{}, 0), "a", "PIPE", "b", "PIPE", "c"),
+		append(make([]interface{}, 0), "a", "b", "c", "PIPE", "PIPE"),
+	},
+	{
+		`[]`,
+		append(make([]interface{}, 0), "[", "EMPTY", "]"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT", "SHORT_PIPE"),
+	},
+	{
+		`{}`,
+		append(make([]interface{}, 0), "{", "EMPTY", "}"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`[{}]`,
+		append(make([]interface{}, 0), "[", "{", "EMPTY", "}", "]"),
+		append(make([]interface{}, 0), "EMPTY", "COLLECT_OBJECT", "SHORT_PIPE", "COLLECT", "SHORT_PIPE"),
+	},
+	{
+		`.realnames as $names | $names["anon"]`,
+		append(make([]interface{}, 0), "realnames", "ASSIGN_VARIABLE", "GET_VARIABLE", "PIPE", "GET_VARIABLE", "TRAVERSE_ARRAY", "[", "anon (string)", "]"),
+		append(make([]interface{}, 0), "realnames", "GET_VARIABLE", "ASSIGN_VARIABLE", "GET_VARIABLE", "anon (string)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "PIPE"),
+	},
+	{
+		`.b[.a]`,
+		append(make([]interface{}, 0), "b", "TRAVERSE_ARRAY", "[", "a", "]"),
+		append(make([]interface{}, 0), "b", "a", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.b[.a]?`,
+		append(make([]interface{}, 0), "b", "TRAVERSE_ARRAY", "[", "a", "]"),
+		append(make([]interface{}, 0), "b", "a", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.[]`,
+		append(make([]interface{}, 0), "SELF", "TRAVERSE_ARRAY", "[", "EMPTY", "]"),
+		append(make([]interface{}, 0), "SELF", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a[]`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "EMPTY", "]"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a[]?`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "EMPTY", "]"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a.[]`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "EMPTY", "]"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a[0]`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a[0]?`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a.[0]`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "0 (int64)", "]"),
+		append(make([]interface{}, 0), "a", "0 (int64)", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY"),
+	},
+	{
+		`.a[].c`,
+		append(make([]interface{}, 0), "a", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "SHORT_PIPE", "c"),
+		append(make([]interface{}, 0), "a", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "c", "SHORT_PIPE"),
+	},
+	{
+		`[3]`,
+		append(make([]interface{}, 0), "[", "3 (int64)", "]"),
+		append(make([]interface{}, 0), "3 (int64)", "COLLECT", "SHORT_PIPE"),
+	},
+	{
+		`.key.array + .key.array2`,
+		append(make([]interface{}, 0), "key", "SHORT_PIPE", "array", "ADD", "key", "SHORT_PIPE", "array2"),
+		append(make([]interface{}, 0), "key", "array", "SHORT_PIPE", "key", "array2", "SHORT_PIPE", "ADD"),
+	},
+	{
+		`.key.array * .key.array2`,
+		append(make([]interface{}, 0), "key", "SHORT_PIPE", "array", "MULTIPLY", "key", "SHORT_PIPE", "array2"),
+		append(make([]interface{}, 0), "key", "array", "SHORT_PIPE", "key", "array2", "SHORT_PIPE", "MULTIPLY"),
+	},
+	{
+		`.key.array // .key.array2`,
+		append(make([]interface{}, 0), "key", "SHORT_PIPE", "array", "ALTERNATIVE", "key", "SHORT_PIPE", "array2"),
+		append(make([]interface{}, 0), "key", "array", "SHORT_PIPE", "key", "array2", "SHORT_PIPE", "ALTERNATIVE"),
+	},
+	{
+		`.a | .[].b == "apple"`,
+		append(make([]interface{}, 0), "a", "PIPE", "SELF", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "SHORT_PIPE", "b", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "a", "SELF", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "apple (string)", "EQUALS", "PIPE"),
+	},
+	{
+		`(.a | .[].b) == "apple"`,
+		append(make([]interface{}, 0), "(", "a", "PIPE", "SELF", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "SHORT_PIPE", "b", ")", "EQUALS", "apple (string)"),
+		append(make([]interface{}, 0), "a", "SELF", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "b", "SHORT_PIPE", "PIPE", "apple (string)", "EQUALS"),
+	},
+	{
+		`.[] | select(. == "*at")`,
+		append(make([]interface{}, 0), "SELF", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "PIPE", "SELECT", "(", "SELF", "EQUALS", "*at (string)", ")"),
+		append(make([]interface{}, 0), "SELF", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SELF", "*at (string)", "EQUALS", "SELECT", "PIPE"),
+	},
+	{
+		`[true]`,
+		append(make([]interface{}, 0), "[", "true (bool)", "]"),
+		append(make([]interface{}, 0), "true (bool)", "COLLECT", "SHORT_PIPE"),
+	},
+	{
+		`[true, false]`,
+		append(make([]interface{}, 0), "[", "true (bool)", "UNION", "false (bool)", "]"),
+		append(make([]interface{}, 0), "true (bool)", "false (bool)", "UNION", "COLLECT", "SHORT_PIPE"),
+	},
+	{
+		`"mike": .a`,
+		append(make([]interface{}, 0), "mike (string)", "CREATE_MAP", "a"),
+		append(make([]interface{}, 0), "mike (string)", "a", "CREATE_MAP"),
+	},
+	{
+		`.a: "mike"`,
+		append(make([]interface{}, 0), "a", "CREATE_MAP", "mike (string)"),
+		append(make([]interface{}, 0), "a", "mike (string)", "CREATE_MAP"),
+	},
+	{
+		`{"mike": .a}`,
+		append(make([]interface{}, 0), "{", "mike (string)", "CREATE_MAP", "a", "}"),
+		append(make([]interface{}, 0), "mike (string)", "a", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`{.a: "mike"}`,
+		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "mike (string)", "}"),
+		append(make([]interface{}, 0), "a", "mike (string)", "CREATE_MAP", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`{.a: .c, .b.[]: .f.g[]}`,
+		append(make([]interface{}, 0), "{", "a", "CREATE_MAP", "c", "UNION", "b", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "CREATE_MAP", "f", "SHORT_PIPE", "g", "TRAVERSE_ARRAY", "[", "EMPTY", "]", "}"),
+		append(make([]interface{}, 0), "a", "c", "CREATE_MAP", "b", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "f", "g", "EMPTY", "COLLECT", "SHORT_PIPE", "TRAVERSE_ARRAY", "SHORT_PIPE", "CREATE_MAP", "UNION", "COLLECT_OBJECT", "SHORT_PIPE"),
+	},
+	{
+		`explode(.a.b)`,
+		append(make([]interface{}, 0), "EXPLODE", "(", "a", "SHORT_PIPE", "b", ")"),
+		append(make([]interface{}, 0), "a", "b", "SHORT_PIPE", "EXPLODE"),
+	},
+	{
+		`.a.b style="folded"`,
+		append(make([]interface{}, 0), "a", "SHORT_PIPE", "b", "ASSIGN_STYLE", "folded (string)"),
+		append(make([]interface{}, 0), "a", "b", "SHORT_PIPE", "folded (string)", "ASSIGN_STYLE"),
+	},
+	{
+		`tag == "str"`,
+		append(make([]interface{}, 0), "GET_TAG", "EQUALS", "str (string)"),
+		append(make([]interface{}, 0), "GET_TAG", "str (string)", "EQUALS"),
+	},
+	{
+		`. tag= "str"`,
+		append(make([]interface{}, 0), "SELF", "ASSIGN_TAG", "str (string)"),
+		append(make([]interface{}, 0), "SELF", "str (string)", "ASSIGN_TAG"),
+	},
+	{
+		`lineComment == "str"`,
+		append(make([]interface{}, 0), "GET_COMMENT", "EQUALS", "str (string)"),
+		append(make([]interface{}, 0), "GET_COMMENT", "str (string)", "EQUALS"),
+	},
+	{
+		`. lineComment= "str"`,
+		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)"),
+		append(make([]interface{}, 0), "a", "b", "SHORT_PIPE", "!!str (string)", "ASSIGN_TAG"),
+	},
+	{
+		`""`,
+		append(make([]interface{}, 0), " (string)"),
+		append(make([]interface{}, 0), " (string)"),
+	},
+	{
+		`.foo* | (. style="flow")`,
+		append(make([]interface{}, 0), "foo*", "PIPE", "(", "SELF", "ASSIGN_STYLE", "flow (string)", ")"),
+		append(make([]interface{}, 0), "foo*", "SELF", "flow (string)", "ASSIGN_STYLE", "PIPE"),
+	},
+}
+
+var tokeniser = newExpressionTokeniser()
+var postFixer = newExpressionPostFixer()
+
+func TestPathParsing(t *testing.T) {
+	for _, tt := range pathTests {
+		tokens, err := tokeniser.Tokenise(tt.path)
+		if err != nil {
+			t.Error(tt.path, err)
+		}
+		var tokenValues []interface{}
+		for _, token := range tokens {
+			tokenValues = append(tokenValues, token.toString(false))
+		}
+		test.AssertResultComplexWithContext(t, tt.expectedTokens, tokenValues, fmt.Sprintf("tokenise: %v", tt.path))
+
+		results, errorP := postFixer.ConvertToPostfix(tokens)
+
+		var readableResults []interface{}
+		for _, token := range results {
+			readableResults = append(readableResults, token.toString())
+		}
+
+		if errorP != nil {
+			t.Error(tt.path, err)
+		}
+
+		test.AssertResultComplexWithContext(t, tt.expectedPostFix, readableResults, fmt.Sprintf("postfix: %v", tt.path))
+
+	}
+}

pkg/yqlib/expression_tokeniser.go

@@ -0,0 +1,474 @@
+package yqlib
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	lex "github.com/timtadh/lexmachine"
+	"github.com/timtadh/lexmachine/machines"
+)
+
+func skip(*lex.Scanner, *machines.Match) (interface{}, error) {
+	return nil, nil
+}
+
+type tokenType uint32
+
+const (
+	operationToken = 1 << iota
+	openBracket
+	closeBracket
+	openCollect
+	closeCollect
+	openCollectObject
+	closeCollectObject
+	traverseArrayCollect
+)
+
+type token struct {
+	TokenType            tokenType
+	Operation            *Operation
+	AssignOperation      *Operation      // e.g. tag (GetTag) op becomes AssignTag if '=' follows it
+	CheckForPostTraverse bool            // e.g. [1]cat should really be [1].cat
+	Match                *machines.Match // match that created this token
+
+}
+
+func (t *token) toString(detail bool) string {
+	if t.TokenType == operationToken {
+		if detail {
+			return fmt.Sprintf("%v (%v)", t.Operation.toString(), t.Operation.OperationType.Precedence)
+		}
+		return t.Operation.toString()
+	} else if t.TokenType == openBracket {
+		return "("
+	} else if t.TokenType == closeBracket {
+		return ")"
+	} else if t.TokenType == openCollect {
+		return "["
+	} else if t.TokenType == closeCollect {
+		return "]"
+	} else if t.TokenType == openCollectObject {
+		return "{"
+	} else if t.TokenType == closeCollectObject {
+		return "}"
+	} else if t.TokenType == traverseArrayCollect {
+		return ".["
+
+	} else {
+		return "NFI"
+	}
+}
+
+func pathToken(wrapped bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		value := string(m.Bytes)
+		prefs := traversePreferences{}
+
+		if value[len(value)-1:] == "?" {
+			prefs.OptionalTraverse = true
+			value = value[:len(value)-1]
+		}
+
+		value = value[1:]
+		if wrapped {
+			value = unwrap(value)
+		}
+		log.Debug("PathToken %v", value)
+		op := &Operation{OperationType: traversePathOpType, Value: value, StringValue: value, Preferences: prefs}
+		return &token{TokenType: operationToken, Operation: op, CheckForPostTraverse: true}, nil
+	}
+}
+
+func opToken(op *operationType) lex.Action {
+	return opTokenWithPrefs(op, nil, nil)
+}
+
+func opAssignableToken(opType *operationType, assignOpType *operationType) lex.Action {
+	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: assignOpType, Value: assignOpType.Type, StringValue: value, UpdateAssign: updateAssign}
+		return &token{TokenType: operationToken, Operation: op}, nil
+	}
+}
+
+func multiplyWithPrefs() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		prefs := multiplyPreferences{}
+		options := string(m.Bytes)
+		if strings.Contains(options, "+") {
+			prefs.AppendArrays = true
+		}
+		if strings.Contains(options, "?") {
+			prefs.TraversePrefs = traversePreferences{DontAutoCreate: true}
+		}
+		if strings.Contains(options, "d") {
+			prefs.DeepMergeArrays = true
+		}
+		op := &Operation{OperationType: multiplyOpType, Value: multiplyOpType.Type, StringValue: options, Preferences: prefs}
+		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))
+		value := string(m.Bytes)
+		op := &Operation{OperationType: op, Value: op.Type, StringValue: value, Preferences: preferences}
+		var assign *Operation
+		if assignOpType != nil {
+			assign = &Operation{OperationType: assignOpType, Value: assignOpType.Type, StringValue: value, Preferences: preferences}
+		}
+		return &token{TokenType: operationToken, Operation: op, AssignOperation: assign}, nil
+	}
+}
+
+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: assignCommentOpType,
+			Value:         assignCommentOpType.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, Match: m}, nil
+	}
+}
+
+func unwrap(value string) string {
+	return value[1 : len(value)-1]
+}
+
+func numberValue() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		var numberString = string(m.Bytes)
+		var number, errParsingInt = strconv.ParseInt(numberString, 10, 64) // nolint
+		if errParsingInt != nil {
+			return nil, errParsingInt
+		}
+
+		return &token{TokenType: operationToken, Operation: createValueOperation(number, numberString)}, nil
+	}
+}
+
+func floatValue() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		var numberString = string(m.Bytes)
+		var number, errParsingInt = strconv.ParseFloat(numberString, 64) // nolint
+		if errParsingInt != nil {
+			return nil, errParsingInt
+		}
+		return &token{TokenType: operationToken, Operation: createValueOperation(number, numberString)}, nil
+	}
+}
+
+func booleanValue(val bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		return &token{TokenType: operationToken, Operation: createValueOperation(val, string(m.Bytes))}, nil
+	}
+}
+
+func stringValue(wrapped bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		value := string(m.Bytes)
+		if wrapped {
+			value = unwrap(value)
+		}
+		value = strings.ReplaceAll(value, "\\\"", "\"")
+		return &token{TokenType: operationToken, Operation: createValueOperation(value, value)}, nil
+	}
+}
+
+func getVariableOpToken() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		value := string(m.Bytes)
+
+		value = value[1:]
+
+		getVarOperation := createValueOperation(value, value)
+		getVarOperation.OperationType = getVariableOpType
+
+		return &token{TokenType: operationToken, Operation: getVarOperation, CheckForPostTraverse: true}, nil
+	}
+}
+
+func envOp(strenv bool) lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		value := string(m.Bytes)
+		preferences := envOpPreferences{}
+
+		if strenv {
+			// strenv( )
+			value = value[7 : len(value)-1]
+			preferences.StringValue = true
+		} else {
+			//env( )
+			value = value[4 : len(value)-1]
+		}
+
+		envOperation := createValueOperation(value, value)
+		envOperation.OperationType = envOpType
+		envOperation.Preferences = preferences
+
+		return &token{TokenType: operationToken, Operation: envOperation}, nil
+	}
+}
+
+func nullValue() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		return &token{TokenType: operationToken, Operation: createValueOperation(nil, string(m.Bytes))}, nil
+	}
+}
+
+func selfToken() lex.Action {
+	return func(s *lex.Scanner, m *machines.Match) (interface{}, error) {
+		op := &Operation{OperationType: selfReferenceOpType}
+		return &token{TokenType: operationToken, Operation: op}, nil
+	}
+}
+
+func initLexer() (*lex.Lexer, error) {
+	lexer := lex.NewLexer()
+	lexer.Add([]byte(`\(`), literalToken(openBracket, false))
+	lexer.Add([]byte(`\)`), literalToken(closeBracket, true))
+
+	lexer.Add([]byte(`\.\[`), literalToken(traverseArrayCollect, false))
+	lexer.Add([]byte(`\.\.`), opTokenWithPrefs(recursiveDescentOpType, nil, recursiveDescentPreferences{RecurseArray: true,
+		TraversePreferences: traversePreferences{DontFollowAlias: true, IncludeMapKeys: false}}))
+
+	lexer.Add([]byte(`\.\.\.`), opTokenWithPrefs(recursiveDescentOpType, nil, recursiveDescentPreferences{RecurseArray: true,
+		TraversePreferences: traversePreferences{DontFollowAlias: true, IncludeMapKeys: true}}))
+
+	lexer.Add([]byte(`,`), opToken(unionOpType))
+	lexer.Add([]byte(`:\s*`), opToken(createMapOpType))
+	lexer.Add([]byte(`length`), opToken(lengthOpType))
+	lexer.Add([]byte(`sortKeys`), opToken(sortKeysOpType))
+	lexer.Add([]byte(`select`), opToken(selectOpType))
+	lexer.Add([]byte(`has`), opToken(hasOpType))
+	lexer.Add([]byte(`unique`), opToken(uniqueOpType))
+	lexer.Add([]byte(`unique_by`), opToken(uniqueByOpType))
+	lexer.Add([]byte(`explode`), opToken(explodeOpType))
+	lexer.Add([]byte(`or`), opToken(orOpType))
+	lexer.Add([]byte(`and`), opToken(andOpType))
+	lexer.Add([]byte(`not`), opToken(notOpType))
+	lexer.Add([]byte(`ireduce`), opToken(reduceOpType))
+	lexer.Add([]byte(`;`), opToken(blockOpType))
+	lexer.Add([]byte(`\/\/`), opToken(alternativeOpType))
+
+	lexer.Add([]byte(`documentIndex`), opToken(getDocumentIndexOpType))
+	lexer.Add([]byte(`di`), opToken(getDocumentIndexOpType))
+	lexer.Add([]byte(`splitDoc`), opToken(splitDocumentOpType))
+
+	lexer.Add([]byte(`join`), opToken(joinStringOpType))
+	lexer.Add([]byte(`sub`), opToken(subStringOpType))
+
+	lexer.Add([]byte(`any`), opToken(anyOpType))
+	lexer.Add([]byte(`any_c`), opToken(anyConditionOpType))
+	lexer.Add([]byte(`all`), opToken(allOpType))
+	lexer.Add([]byte(`all_c`), opToken(allConditionOpType))
+
+	lexer.Add([]byte(`split`), opToken(splitStringOpType))
+	lexer.Add([]byte(`keys`), opToken(keysOpType))
+
+	lexer.Add([]byte(`style`), opAssignableToken(getStyleOpType, assignStyleOpType))
+
+	lexer.Add([]byte(`tag`), opAssignableToken(getTagOpType, assignTagOpType))
+	lexer.Add([]byte(`anchor`), opAssignableToken(getAnchorOpType, assignAnchorOpType))
+	lexer.Add([]byte(`alias`), opAssignableToken(getAliasOptype, assignAliasOpType))
+	lexer.Add([]byte(`filename`), opToken(getFilenameOpType))
+	lexer.Add([]byte(`fileIndex`), opToken(getFileIndexOpType))
+	lexer.Add([]byte(`fi`), opToken(getFileIndexOpType))
+	lexer.Add([]byte(`path`), opToken(getPathOpType))
+	lexer.Add([]byte(`to_entries`), opToken(toEntriesOpType))
+	lexer.Add([]byte(`from_entries`), opToken(fromEntriesOpType))
+	lexer.Add([]byte(`with_entries`), opToken(withEntriesOpType))
+
+	lexer.Add([]byte(`lineComment`), opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{LineComment: true}))
+
+	lexer.Add([]byte(`headComment`), opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{HeadComment: true}))
+
+	lexer.Add([]byte(`footComment`), opTokenWithPrefs(getCommentOpType, assignCommentOpType, commentOpPreferences{FootComment: true}))
+
+	lexer.Add([]byte(`comments\s*=`), assignAllCommentsOp(false))
+	lexer.Add([]byte(`comments\s*\|=`), assignAllCommentsOp(true))
+
+	lexer.Add([]byte(`collect`), opToken(collectOpType))
+
+	lexer.Add([]byte(`\s*==\s*`), opToken(equalsOpType))
+	lexer.Add([]byte(`\s*!=\s*`), opToken(notEqualsOpType))
+	lexer.Add([]byte(`\s*=\s*`), assignOpToken(false))
+
+	lexer.Add([]byte(`del`), opToken(deleteChildOpType))
+
+	lexer.Add([]byte(`\s*\|=\s*`), assignOpToken(true))
+
+	lexer.Add([]byte("( |\t|\n|\r)+"), skip)
+
+	lexer.Add([]byte(`\."[^ "]+"\??`), pathToken(true))
+	lexer.Add([]byte(`\.[^ \}\{\:\[\],\|\.\[\(\)=]+\??`), pathToken(false))
+	lexer.Add([]byte(`\.`), selfToken())
+
+	lexer.Add([]byte(`\|`), opToken(pipeOpType))
+
+	lexer.Add([]byte(`-?\d+(\.\d+)`), floatValue())
+	lexer.Add([]byte(`-?[1-9](\.\d+)?[Ee][-+]?\d+`), floatValue())
+	lexer.Add([]byte(`-?\d+`), numberValue())
+
+	lexer.Add([]byte(`[Tt][Rr][Uu][Ee]`), booleanValue(true))
+	lexer.Add([]byte(`[Ff][Aa][Ll][Ss][Ee]`), booleanValue(false))
+
+	lexer.Add([]byte(`[Nn][Uu][Ll][Ll]`), nullValue())
+	lexer.Add([]byte(`~`), nullValue())
+
+	lexer.Add([]byte(`"([^"\\]*(\\.[^"\\]*)*)"`), stringValue(true))
+	lexer.Add([]byte(`strenv\([^\)]+\)`), envOp(true))
+	lexer.Add([]byte(`env\([^\)]+\)`), envOp(false))
+
+	lexer.Add([]byte(`\[`), literalToken(openCollect, false))
+	lexer.Add([]byte(`\]\??`), literalToken(closeCollect, true))
+	lexer.Add([]byte(`\{`), literalToken(openCollectObject, false))
+	lexer.Add([]byte(`\}`), literalToken(closeCollectObject, true))
+	lexer.Add([]byte(`\*[\+|\?d]*`), multiplyWithPrefs())
+	lexer.Add([]byte(`\+`), opToken(addOpType))
+	lexer.Add([]byte(`\+=`), opToken(addAssignOpType))
+	lexer.Add([]byte(`\-`), opToken(subtractOpType))
+	lexer.Add([]byte(`\-=`), opToken(subtractAssignOpType))
+	lexer.Add([]byte(`\$[a-zA-Z_-0-9]+`), getVariableOpToken())
+	lexer.Add([]byte(`as`), opToken(assignVariableOpType))
+
+	err := lexer.CompileNFA()
+	if err != nil {
+		return nil, err
+	}
+	return lexer, nil
+}
+
+type expressionTokeniser interface {
+	Tokenise(expression string) ([]*token, error)
+}
+
+type expressionTokeniserImpl struct {
+	lexer *lex.Lexer
+}
+
+func newExpressionTokeniser() expressionTokeniser {
+	var lexer, err = initLexer()
+	if err != nil {
+		panic(err)
+	}
+	return &expressionTokeniserImpl{lexer}
+}
+
+func (p *expressionTokeniserImpl) Tokenise(expression string) ([]*token, error) {
+	scanner, err := p.lexer.Scanner([]byte(expression))
+
+	if err != nil {
+		return nil, fmt.Errorf("Parsing expression: %v", err)
+	}
+	var tokens []*token
+	for tok, err, eof := scanner.Next(); !eof; tok, err, eof = scanner.Next() {
+
+		if tok != nil {
+			currentToken := tok.(*token)
+			log.Debugf("Tokenising %v", currentToken.toString(true))
+			tokens = append(tokens, currentToken)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("Parsing expression: %v", err)
+		}
+	}
+	var postProcessedTokens = make([]*token, 0)
+
+	skipNextToken := false
+
+	for index := range tokens {
+		if skipNextToken {
+			skipNextToken = false
+		} else {
+			postProcessedTokens, skipNextToken = p.handleToken(tokens, index, postProcessedTokens)
+		}
+	}
+
+	return postProcessedTokens, nil
+}
+
+func (p *expressionTokeniserImpl) handleToken(tokens []*token, index int, postProcessedTokens []*token) (tokensAccum []*token, skipNextToken bool) {
+	skipNextToken = false
+	currentToken := tokens[index]
+
+	log.Debug("processing %v", currentToken.toString(true))
+
+	if currentToken.TokenType == traverseArrayCollect {
+		//need to put a traverse array then a collect currentToken
+		// do this by adding traverse then converting currentToken to collect
+
+		if index == 0 || tokens[index-1].TokenType != operationToken ||
+			tokens[index-1].Operation.OperationType != traversePathOpType {
+			log.Debug("  adding self")
+			op := &Operation{OperationType: selfReferenceOpType, StringValue: "SELF"}
+			postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+		}
+		log.Debug("  adding traverse array")
+		op := &Operation{OperationType: traverseArrayOpType, StringValue: "TRAVERSE_ARRAY"}
+		postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+
+		currentToken = &token{TokenType: openCollect}
+
+	}
+
+	if index != len(tokens)-1 && currentToken.AssignOperation != nil &&
+		tokens[index+1].TokenType == operationToken &&
+		tokens[index+1].Operation.OperationType == assignOpType {
+		log.Debug("  its an update assign")
+		currentToken.Operation = currentToken.AssignOperation
+		currentToken.Operation.UpdateAssign = tokens[index+1].Operation.UpdateAssign
+		skipNextToken = true
+	}
+
+	log.Debug("  adding token to the fixed list")
+	postProcessedTokens = append(postProcessedTokens, currentToken)
+
+	if index != len(tokens)-1 &&
+		((currentToken.TokenType == openCollect && tokens[index+1].TokenType == closeCollect) ||
+			(currentToken.TokenType == openCollectObject && tokens[index+1].TokenType == closeCollectObject)) {
+		log.Debug("  adding empty")
+		op := &Operation{OperationType: emptyOpType, StringValue: "EMPTY"}
+		postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+	}
+
+	if index != len(tokens)-1 && currentToken.CheckForPostTraverse &&
+		tokens[index+1].TokenType == operationToken &&
+		tokens[index+1].Operation.OperationType == traversePathOpType {
+		log.Debug("  adding pipe because the next thing is traverse")
+		op := &Operation{OperationType: shortPipeOpType, Value: "PIPE"}
+		postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+	}
+	if index != len(tokens)-1 && currentToken.CheckForPostTraverse &&
+		tokens[index+1].TokenType == openCollect {
+
+		// if tokens[index].TokenType == closeCollect {
+		// 	log.Debug("  adding pipe because next is opencollect")
+		// 	op := &Operation{OperationType: shortPipeOpType, Value: "PIPE"}
+		// 	postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+		// }
+		log.Debug("  adding traverArray because next is opencollect")
+		op := &Operation{OperationType: traverseArrayOpType}
+		postProcessedTokens = append(postProcessedTokens, &token{TokenType: operationToken, Operation: op})
+	}
+	return postProcessedTokens, skipNextToken
+}

pkg/yqlib/file_utils.go

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

pkg/yqlib/lib.go

@@ -1,3 +1,5 @@
+// Use the top level Evaluator or StreamEvaluator to evaluate expressions and return matches.
+//
 package yqlib
 
 import (
@@ -9,79 +11,110 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
-type OperationType struct {
+var log = logging.MustGetLogger("yq-lib")
+
+type operationType struct {
 	Type       string
 	NumArgs    uint // number of arguments to the op
 	Precedence uint
-	Handler    OperatorHandler
+	Handler    operatorHandler
 }
 
-// operators TODO:
-// - write in place
-// - mergeAppend (merges and appends arrays)
-// - mergeEmpty (sets only if the document is empty, do I do that now?)
-// - compare ??
-// - validate ??
-// - exists
+var orOpType = &operationType{Type: "OR", NumArgs: 2, Precedence: 20, Handler: orOperator}
+var andOpType = &operationType{Type: "AND", NumArgs: 2, Precedence: 20, Handler: andOperator}
+var reduceOpType = &operationType{Type: "REDUCE", NumArgs: 2, Precedence: 35, Handler: reduceOperator}
 
-var Or = &OperationType{Type: "OR", NumArgs: 2, Precedence: 20, Handler: OrOperator}
-var And = &OperationType{Type: "AND", NumArgs: 2, Precedence: 20, Handler: AndOperator}
+var blockOpType = &operationType{Type: "BLOCK", Precedence: 10, NumArgs: 2, Handler: emptyOperator}
 
-var Union = &OperationType{Type: "UNION", NumArgs: 2, Precedence: 10, Handler: UnionOperator}
+var unionOpType = &operationType{Type: "UNION", NumArgs: 2, Precedence: 10, Handler: unionOperator}
 
-var Assign = &OperationType{Type: "ASSIGN", NumArgs: 2, Precedence: 40, Handler: AssignUpdateOperator}
+var pipeOpType = &operationType{Type: "PIPE", NumArgs: 2, Precedence: 30, Handler: pipeOperator}
 
-var AssignAttributes = &OperationType{Type: "ASSIGN_ATTRIBUTES", NumArgs: 2, Precedence: 40, Handler: AssignAttributesOperator}
-var AssignStyle = &OperationType{Type: "ASSIGN_STYLE", NumArgs: 2, Precedence: 40, Handler: AssignStyleOperator}
-var AssignTag = &OperationType{Type: "ASSIGN_TAG", NumArgs: 2, Precedence: 40, Handler: AssignTagOperator}
-var AssignComment = &OperationType{Type: "ASSIGN_COMMENT", NumArgs: 2, Precedence: 40, Handler: AssignCommentsOperator}
+var assignOpType = &operationType{Type: "ASSIGN", NumArgs: 2, Precedence: 40, Handler: assignUpdateOperator}
+var addAssignOpType = &operationType{Type: "ADD_ASSIGN", NumArgs: 2, Precedence: 40, Handler: addAssignOperator}
+var subtractAssignOpType = &operationType{Type: "SUBTRACT_ASSIGN", NumArgs: 2, Precedence: 40, Handler: subtractAssignOperator}
 
-var Multiply = &OperationType{Type: "MULTIPLY", NumArgs: 2, Precedence: 45, Handler: MultiplyOperator}
-var Add = &OperationType{Type: "ADD", NumArgs: 2, Precedence: 45, Handler: AddOperator}
+var assignAttributesOpType = &operationType{Type: "ASSIGN_ATTRIBUTES", NumArgs: 2, Precedence: 40, Handler: assignAttributesOperator}
+var assignStyleOpType = &operationType{Type: "ASSIGN_STYLE", NumArgs: 2, Precedence: 40, Handler: assignStyleOperator}
+var assignVariableOpType = &operationType{Type: "ASSIGN_VARIABLE", NumArgs: 2, Precedence: 40, Handler: assignVariableOperator}
+var assignTagOpType = &operationType{Type: "ASSIGN_TAG", NumArgs: 2, Precedence: 40, Handler: assignTagOperator}
+var assignCommentOpType = &operationType{Type: "ASSIGN_COMMENT", NumArgs: 2, Precedence: 40, Handler: assignCommentsOperator}
+var assignAnchorOpType = &operationType{Type: "ASSIGN_ANCHOR", NumArgs: 2, Precedence: 40, Handler: assignAnchorOperator}
+var assignAliasOpType = &operationType{Type: "ASSIGN_ALIAS", NumArgs: 2, Precedence: 40, Handler: assignAliasOperator}
 
-var Equals = &OperationType{Type: "EQUALS", NumArgs: 2, Precedence: 40, Handler: EqualsOperator}
-var CreateMap = &OperationType{Type: "CREATE_MAP", NumArgs: 2, Precedence: 40, Handler: CreateMapOperator}
-var Pipe = &OperationType{Type: "PIPE", NumArgs: 2, Precedence: 45, Handler: PipeOperator}
+var multiplyOpType = &operationType{Type: "MULTIPLY", NumArgs: 2, Precedence: 42, Handler: multiplyOperator}
+var addOpType = &operationType{Type: "ADD", NumArgs: 2, Precedence: 42, Handler: addOperator}
+var subtractOpType = &operationType{Type: "SUBTRACT", NumArgs: 2, Precedence: 42, Handler: subtractOperator}
+var alternativeOpType = &operationType{Type: "ALTERNATIVE", NumArgs: 2, Precedence: 42, Handler: alternativeOperator}
 
-var Length = &OperationType{Type: "LENGTH", NumArgs: 0, Precedence: 50, Handler: LengthOperator}
-var Collect = &OperationType{Type: "COLLECT", NumArgs: 0, Precedence: 50, Handler: CollectOperator}
-var GetStyle = &OperationType{Type: "GET_STYLE", NumArgs: 0, Precedence: 50, Handler: GetStyleOperator}
-var GetTag = &OperationType{Type: "GET_TAG", NumArgs: 0, Precedence: 50, Handler: GetTagOperator}
-var GetComment = &OperationType{Type: "GET_COMMENT", NumArgs: 0, Precedence: 50, Handler: GetCommentsOperator}
-var GetDocumentIndex = &OperationType{Type: "GET_DOCUMENT_INDEX", NumArgs: 0, Precedence: 50, Handler: GetDocumentIndexOperator}
-var GetFilename = &OperationType{Type: "GET_FILENAME", NumArgs: 0, Precedence: 50, Handler: GetFilenameOperator}
-var GetFileIndex = &OperationType{Type: "GET_FILE_INDEX", NumArgs: 0, Precedence: 50, Handler: GetFileIndexOperator}
-var GetPath = &OperationType{Type: "GET_PATH", NumArgs: 0, Precedence: 50, Handler: GetPathOperator}
+var equalsOpType = &operationType{Type: "EQUALS", NumArgs: 2, Precedence: 40, Handler: equalsOperator}
+var notEqualsOpType = &operationType{Type: "EQUALS", NumArgs: 2, Precedence: 40, Handler: notEqualsOperator}
 
-var Explode = &OperationType{Type: "EXPLODE", NumArgs: 1, Precedence: 50, Handler: ExplodeOperator}
+//createmap needs to be above union, as we use union to build the components of the objects
+var createMapOpType = &operationType{Type: "CREATE_MAP", NumArgs: 2, Precedence: 15, Handler: createMapOperator}
 
-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 shortPipeOpType = &operationType{Type: "SHORT_PIPE", NumArgs: 2, Precedence: 45, Handler: pipeOperator}
 
-var DocumentFilter = &OperationType{Type: "DOCUMENT_FILTER", NumArgs: 0, Precedence: 50, Handler: TraversePathOperator}
-var SelfReference = &OperationType{Type: "SELF", NumArgs: 0, Precedence: 50, Handler: SelfOperator}
-var ValueOp = &OperationType{Type: "VALUE", NumArgs: 0, Precedence: 50, Handler: ValueOperator}
-var Not = &OperationType{Type: "NOT", NumArgs: 0, Precedence: 50, Handler: NotOperator}
-var Empty = &OperationType{Type: "EMPTY", NumArgs: 50, Handler: EmptyOperator}
+var lengthOpType = &operationType{Type: "LENGTH", NumArgs: 0, Precedence: 50, Handler: lengthOperator}
+var collectOpType = &operationType{Type: "COLLECT", NumArgs: 0, Precedence: 50, Handler: collectOperator}
 
-var RecursiveDescent = &OperationType{Type: "RECURSIVE_DESCENT", NumArgs: 0, Precedence: 50, Handler: RecursiveDescentOperator}
+var anyOpType = &operationType{Type: "ANY", NumArgs: 0, Precedence: 50, Handler: anyOperator}
+var allOpType = &operationType{Type: "ALL", NumArgs: 0, Precedence: 50, Handler: allOperator}
+var anyConditionOpType = &operationType{Type: "ANY_CONDITION", NumArgs: 1, Precedence: 50, Handler: anyOperator}
+var allConditionOpType = &operationType{Type: "ALL_CONDITION", NumArgs: 1, Precedence: 50, Handler: allOperator}
 
-var Select = &OperationType{Type: "SELECT", NumArgs: 1, Precedence: 50, Handler: SelectOperator}
-var Has = &OperationType{Type: "HAS", NumArgs: 1, Precedence: 50, Handler: HasOperator}
-var DeleteChild = &OperationType{Type: "DELETE", NumArgs: 1, Precedence: 40, Handler: DeleteChildOperator}
+var toEntriesOpType = &operationType{Type: "TO_ENTRIES", NumArgs: 0, Precedence: 50, Handler: toEntriesOperator}
+var fromEntriesOpType = &operationType{Type: "FROM_ENTRIES", NumArgs: 0, Precedence: 50, Handler: fromEntriesOperator}
+var withEntriesOpType = &operationType{Type: "WITH_ENTRIES", NumArgs: 1, Precedence: 50, Handler: withEntriesOperator}
 
-// var Exists = &OperationType{Type: "Length", NumArgs: 2, Precedence: 35}
-// filters matches if they have the existing path
+var splitDocumentOpType = &operationType{Type: "SPLIT_DOC", NumArgs: 0, Precedence: 50, Handler: splitDocumentOperator}
+var getVariableOpType = &operationType{Type: "GET_VARIABLE", NumArgs: 0, Precedence: 55, Handler: getVariableOperator}
+var getStyleOpType = &operationType{Type: "GET_STYLE", NumArgs: 0, Precedence: 50, Handler: getStyleOperator}
+var getTagOpType = &operationType{Type: "GET_TAG", NumArgs: 0, Precedence: 50, Handler: getTagOperator}
+var getCommentOpType = &operationType{Type: "GET_COMMENT", NumArgs: 0, Precedence: 50, Handler: getCommentsOperator}
+var getAnchorOpType = &operationType{Type: "GET_ANCHOR", NumArgs: 0, Precedence: 50, Handler: getAnchorOperator}
+var getAliasOptype = &operationType{Type: "GET_ALIAS", NumArgs: 0, Precedence: 50, Handler: getAliasOperator}
+var getDocumentIndexOpType = &operationType{Type: "GET_DOCUMENT_INDEX", NumArgs: 0, Precedence: 50, Handler: getDocumentIndexOperator}
+var getFilenameOpType = &operationType{Type: "GET_FILENAME", NumArgs: 0, Precedence: 50, Handler: getFilenameOperator}
+var getFileIndexOpType = &operationType{Type: "GET_FILE_INDEX", NumArgs: 0, Precedence: 50, Handler: getFileIndexOperator}
+var getPathOpType = &operationType{Type: "GET_PATH", NumArgs: 0, Precedence: 50, Handler: getPathOperator}
+
+var explodeOpType = &operationType{Type: "EXPLODE", NumArgs: 1, Precedence: 50, Handler: explodeOperator}
+var sortKeysOpType = &operationType{Type: "SORT_KEYS", NumArgs: 1, Precedence: 50, Handler: sortKeysOperator}
+var joinStringOpType = &operationType{Type: "JOIN", NumArgs: 1, Precedence: 50, Handler: joinStringOperator}
+var subStringOpType = &operationType{Type: "SUBSTR", NumArgs: 1, Precedence: 50, Handler: substituteStringOperator}
+var splitStringOpType = &operationType{Type: "SPLIT", NumArgs: 1, Precedence: 50, Handler: splitStringOperator}
+
+var keysOpType = &operationType{Type: "KEYS", NumArgs: 0, Precedence: 50, Handler: keysOperator}
+
+var collectObjectOpType = &operationType{Type: "COLLECT_OBJECT", NumArgs: 0, Precedence: 50, Handler: collectObjectOperator}
+var traversePathOpType = &operationType{Type: "TRAVERSE_PATH", NumArgs: 0, Precedence: 55, Handler: traversePathOperator}
+var traverseArrayOpType = &operationType{Type: "TRAVERSE_ARRAY", NumArgs: 2, Precedence: 50, Handler: traverseArrayOperator}
+
+var selfReferenceOpType = &operationType{Type: "SELF", NumArgs: 0, Precedence: 55, Handler: selfOperator}
+var valueOpType = &operationType{Type: "VALUE", NumArgs: 0, Precedence: 50, Handler: valueOperator}
+var envOpType = &operationType{Type: "ENV", NumArgs: 0, Precedence: 50, Handler: envOperator}
+var notOpType = &operationType{Type: "NOT", NumArgs: 0, Precedence: 50, Handler: notOperator}
+var emptyOpType = &operationType{Type: "EMPTY", Precedence: 50, Handler: emptyOperator}
+
+var recursiveDescentOpType = &operationType{Type: "RECURSIVE_DESCENT", NumArgs: 0, Precedence: 50, Handler: recursiveDescentOperator}
+
+var selectOpType = &operationType{Type: "SELECT", NumArgs: 1, Precedence: 50, Handler: selectOperator}
+var hasOpType = &operationType{Type: "HAS", NumArgs: 1, Precedence: 50, Handler: hasOperator}
+var uniqueOpType = &operationType{Type: "UNIQUE", NumArgs: 0, Precedence: 50, Handler: unique}
+var uniqueByOpType = &operationType{Type: "UNIQUE_BY", NumArgs: 1, Precedence: 50, Handler: uniqueBy}
+var deleteChildOpType = &operationType{Type: "DELETE", NumArgs: 1, Precedence: 40, Handler: deleteChildOperator}
 
 type Operation struct {
-	OperationType *OperationType
+	OperationType *operationType
 	Value         interface{}
 	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
 }
 
-func CreateValueOperation(value interface{}, stringValue string) *Operation {
+func createValueOperation(value interface{}, stringValue string) *Operation {
 	var node yaml.Node = yaml.Node{Kind: yaml.ScalarNode}
 	node.Value = stringValue
 
@@ -99,7 +132,7 @@ func CreateValueOperation(value interface{}, stringValue string) *Operation {
 	}
 
 	return &Operation{
-		OperationType: ValueOp,
+		OperationType: valueOpType,
 		Value:         value,
 		StringValue:   stringValue,
 		CandidateNode: &CandidateNode{Node: &node},
@@ -108,13 +141,11 @@ func CreateValueOperation(value interface{}, stringValue string) *Operation {
 
 // debugging purposes only
 func (p *Operation) toString() string {
-	if p.OperationType == TraversePath {
+	if p.OperationType == traversePathOpType {
 		return fmt.Sprintf("%v", p.Value)
-	} else if p.OperationType == DocumentFilter {
-		return fmt.Sprintf("d%v", p.Value)
-	} else if p.OperationType == SelfReference {
+	} else if p.OperationType == selfReferenceOpType {
 		return "SELF"
-	} else if p.OperationType == ValueOp {
+	} else if p.OperationType == valueOpType {
 		return fmt.Sprintf("%v (%T)", p.Value, p.Value)
 	} else {
 		return fmt.Sprintf("%v", p.OperationType.Type)