feat: fromyaml and toyaml

README.md

@@ -79,6 +79,7 @@ docker run -i --rm ghcr.io/itchyny/gojq
 - gojq behaves differently than jq in some features, expecting jq to fix its behavior in the future. gojq supports string indexing; `"abcde"[2]` ([jq#1520](https://github.com/jqlang/jq/issues/1520)). gojq fixes handling files with no newline characters at the end ([jq#2374](https://github.com/jqlang/jq/issues/2374)). gojq fixes `@base64d` to allow binary string as the decoded string ([jq#1931](https://github.com/jqlang/jq/issues/1931)). gojq improves time formatting and parsing; deals with `%f` in `strftime` and `strptime` ([jq#1409](https://github.com/jqlang/jq/issues/1409)), parses timezone offsets with `fromdate` and `fromdateiso8601` ([jq#1053](https://github.com/jqlang/jq/issues/1053)), supports timezone name/offset with `%Z`/`%z` in `strptime` ([jq#929](https://github.com/jqlang/jq/issues/929), [jq#2195](https://github.com/jqlang/jq/issues/2195)). gojq supports nanoseconds in date and time functions.
 - gojq does not support some functions intentionally; `get_jq_origin`, `get_prog_origin`, `get_search_list` (unstable, not listed in jq document), `input_line_number`, `$__loc__` (performance issue). gojq does not support some flags; `--ascii-output, -a` (performance issue), `--seq` (not used commonly), `--sort-keys, -S` (sorts by default because `map[string]any` does not keep the order), `--unbuffered` (unbuffered by default). gojq does not parse JSON extensions supported by jq; `NaN`, `Infinity`, and `[000]`. gojq does not support some regular expression metacharacters, backreferences, look-around assertions, and some flags (regular expression engine differences). gojq does not support BOM (`encoding/json` does not support this). gojq disallows using keywords for function names (`def true: .; true` is a confusing query), and module name prefixes in function declarations (using module prefixes like `def m::f: .;` is undocumented).
 - gojq supports reading from YAML input (`--yaml-input`) while jq does not. gojq also supports YAML output (`--yaml-output`).
+- gojq supports `fromyaml` and `toyaml` functions to convert values to/from YAML, whereas jq only supports `fromjson` and `tojson` for JSON.
 
 ### Color configuration
 The gojq command automatically disables coloring output when the output is not a tty.

cli/test.yaml

@@ -3867,6 +3867,41 @@
     "[\"foo\"]"
     "{\"a\":[1,2,3]}"
 
+- name: toyaml function
+  args:
+    - 'toyaml'
+  input: |
+    null
+    false
+    true
+    42
+    "foo"
+    ["apple", "banana", "orange"]
+    {"name": "John", "age": 30}
+  expected: |
+    "null"
+    "false"
+    "true"
+    "42"
+    "foo"
+    "- apple\n- banana\n- orange"
+    "age: 30\nname: John"
+
+- name: toyaml function with nested structure
+  args:
+    - 'toyaml'
+  input: |
+    {"person": {"name": "Alice", "age": 25, "hobbies": ["reading", "coding"]}}
+  expected: |
+    "person:\n    age: 25\n    hobbies:\n        - reading\n        - coding\n    name: Alice"
+
+- name: toyaml function with large number
+  args:
+    - 'toyaml'
+  input: '{"number": 4722366482869645213696}'
+  expected: |
+    "number: 4722366482869645213696"
+
 - name: fromjson function
   args:
     - -c
@@ -3895,6 +3930,52 @@
   error: |
     fromjson cannot be applied to "[0": unexpected EOF
 
+- name: fromyaml function
+  args:
+    - -c
+    - 'fromyaml'
+  input: |
+    "null"
+    "false"
+    "true"
+    "42"
+    "foo"
+    "- apple\n- banana\n- orange"
+    "name: John\nage: 30"
+    "person:\n  name: Alice\n  age: 25\n  hobbies:\n    - reading\n    - coding"
+  expected: |
+    null
+    false
+    true
+    42
+    "foo"
+    ["apple","banana","orange"]
+    {"age":30,"name":"John"}
+    {"person":{"age":25,"hobbies":["reading","coding"],"name":"Alice"}}
+
+- name: fromyaml function with numbers
+  args:
+    - 'fromyaml'
+  input: '"number: 4722366482869645213696"'
+  expected: |
+    {
+      "number": 4722366482869645213696
+    }
+
+- name: fromyaml function error
+  args:
+    - 'fromyaml'
+  input: '"invalid: yaml: ["'
+  error: |
+    fromyaml cannot be applied to "invalid: yaml: [": yaml: line 1: mapping values are not allowed in this context
+
+- name: fromyaml function type error
+  args:
+    - 'fromyaml'
+  input: '123'
+  error: |
+    fromyaml cannot be applied to: number (123)
+
 - name: variable definition
   args:
     - -c

encoder.go

@@ -11,6 +11,8 @@ import (
 	"strconv"
 	"strings"
 	"unicode/utf8"
+
+	"github.com/itchyny/go-yaml"
 )
 
 // Marshal returns the jq-flavored JSON encoding of v.
@@ -34,6 +36,19 @@ func jsonMarshal(v any) string {
 	return sb.String()
 }
 
+func yamlMarshal(v any) (string, error) {
+	b, err := yaml.Marshal(v)
+	if err != nil {
+		return "", err
+	}
+	// Remove trailing newline if present
+	s := string(b)
+	if len(s) > 0 && s[len(s)-1] == '\n' {
+		s = s[:len(s)-1]
+	}
+	return s, nil
+}
+
 func jsonEncodeString(sb *strings.Builder, v string) {
 	(&encoder{w: sb}).encodeString(v)
 }

func.go

@@ -19,6 +19,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
+	"github.com/itchyny/go-yaml"
 	"github.com/itchyny/timefmt-go"
 )
 
@@ -85,6 +86,8 @@ func init() {
 		"ascii_upcase":   argFunc0(funcASCIIUpcase),
 		"tojson":         argFunc0(funcToJSON),
 		"fromjson":       argFunc0(funcFromJSON),
+		"toyaml":         argFunc0(funcToYAML),
+		"fromyaml":       argFunc0(funcFromYAML),
 		"format":         argFunc1(funcFormat),
 		"_tohtml":        argFunc0(funcToHTML),
 		"_touri":         argFunc0(funcToURI),
@@ -871,6 +874,14 @@ func funcToJSON(v any) any {
 	return jsonMarshal(v)
 }
 
+func funcToYAML(v any) any {
+	s, err := yamlMarshal(v)
+	if err != nil {
+		return &func0WrapError{"toyaml", v, err}
+	}
+	return s
+}
+
 func funcFromJSON(v any) any {
 	s, ok := v.(string)
 	if !ok {
@@ -888,6 +899,19 @@ func funcFromJSON(v any) any {
 	return w
 }
 
+func funcFromYAML(v any) any {
+	s, ok := v.(string)
+	if !ok {
+		return &func0TypeError{"fromyaml", v}
+	}
+	var w any
+	dec := yaml.NewDecoder(strings.NewReader(s))
+	if err := dec.Decode(&w); err != nil {
+		return &func0WrapError{"fromyaml", v, err}
+	}
+	return w
+}
+
 func funcFormat(v, x any) any {
 	s, ok := x.(string)
 	if !ok {