gojq

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Published: Oct 10, 2023 License: MIT Imports: 20 Imported by: 0

README

gojq

CI Status Go Report Card MIT License release pkg.go.dev

Pure Go implementation of jq

This is an implementation of jq command written in Go language. You can also embed gojq as a library to your Go products.

Usage

 $ echo '{"foo": 128}' | gojq '.foo'
128
 $ echo '{"a": {"b": 42}}' | gojq '.a.b'
42
 $ echo '{"id": "sample", "10": {"b": 42}}' | gojq '{(.id): .["10"].b}'
{
  "sample": 42
}
 $ echo '[{"id":1},{"id":2},{"id":3}]' | gojq '.[] | .id'
1
2
3
 $ echo '{"a":1,"b":2}' | gojq '.a += 1 | .b *= 2'
{
  "a": 2,
  "b": 4
}
 $ echo '{"a":1} [2] 3' | gojq '. as {$a} ?// [$a] ?// $a | $a'
1
2
3
 $ echo '{"foo": 4722366482869645213696}' | gojq .foo
4722366482869645213696  # keeps the precision of large numbers
 $ gojq -n 'def fact($n): if $n < 1 then 1 else $n * fact($n - 1) end; fact(50)'
30414093201713378043612608166064768844377641568960512000000000000 # arbitrary-precision integer calculation

Nice error messages.

 $ echo '[1,2,3]' | gojq '.foo & .bar'
gojq: invalid query: .foo & .bar
    .foo & .bar
         ^  unexpected token "&"
 $ echo '{"foo": { bar: [] } }' | gojq '.'
gojq: invalid json: <stdin>
    {"foo": { bar: [] } }
              ^  invalid character 'b' looking for beginning of object key string

Installation

Homebrew
brew install gojq
Zero Install
0install add gojq https://apps.0install.net/utils/gojq.xml
Build from source
go install github.com/itchyny/gojq/cmd/gojq@latest
Docker
docker run -i --rm itchyny/gojq
docker run -i --rm ghcr.io/itchyny/gojq

Difference to jq

  • gojq is purely implemented with Go language and is completely portable. jq depends on the C standard library so the availability of math functions depends on the library. jq also depends on the regular expression library and it makes build scripts complex.
  • gojq implements nice error messages for invalid query and JSON input. The error message of jq is sometimes difficult to tell where to fix the query.
  • gojq does not keep the order of object keys. I understand this might cause problems for some scripts but basically, we should not rely on the order of object keys. Due to this limitation, gojq does not have keys_unsorted function and --sort-keys (-S) option. I would implement when ordered map is implemented in the standard library of Go but I'm less motivated.
  • gojq supports arbitrary-precision integer calculation while jq does not; jq loses the precision of large integers when calculation is involved. Note that even with gojq, all mathematical functions, including floor and round, convert integers to floating-point numbers; only addition, subtraction, multiplication, modulo, and division operators (when divisible) keep the integer precision. To calculate floor division of integers without losing the precision, use def idivide($n): (. - . % $n) / $n;. To round down floating-point numbers to integers, use def ifloor: floor | tostring | tonumber;, but note that this function does not work with large floating-point numbers and also loses the precision of large integers.
  • gojq fixes various bugs of jq. gojq correctly deletes elements of arrays by |= empty (jq#2051). gojq fixes try/catch handling (jq#1859, jq#1885, jq#2140). gojq fixes nth/2 to output nothing when the count is equal to or larger than the stream size (jq#1867). gojq consistently counts by characters (not by bytes) in index, rindex, and indices functions; "12345" | .[index("3"):] results in "345" (jq#1430, jq#1624). gojq handles overlapping occurrence differently in rindex and indices; "ababa" | [rindex("aba"), indices("aba")] results in [2,[0,2]] (jq#2433). gojq supports string indexing; "abcde"[2] (jq#1520). gojq accepts indexing query .e0 (jq#1526, jq#1651), and allows gsub to handle patterns including "^" (jq#2148). gojq improves variable lexer to allow using keywords for variable names, especially in binding patterns, also disallows spaces after $ (jq#526). gojq fixes handling files with no newline characters at the end (jq#2374).
  • gojq truncates down floating-point numbers on indexing ([0] | .[0.5] results in 0 not null), and slicing ([0,1,2] | .[0.5:1.5] results in [0] not [0,1]). gojq parses unary operators with higher precedence than variable binding ([-1 as $x | 1,$x] results in [1,-1] not [-1,-1]). gojq implements @uri to escape all the reserved characters defined in RFC 3986, Sec. 2.2 (jq#1506), and fixes @base64d to allow binary string as the decoded string (jq#1931). gojq improves time formatting and parsing; deals with %f in strftime and strptime (jq#1409), parses timezone offsets with fromdate and fromdateiso8601 (jq#1053), supports timezone name/offset with %Z/%z in strptime (jq#929, jq#2195), and looks up correct timezone during daylight saving time on formatting with %Z (jq#1912). 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), recurse_down (deprecated in jq). 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 normalizes floating-point numbers to fit to double-precision floating-point numbers. gojq does not support or behaves differently with some regular expression metacharacters and 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 a few filters missing in jq; scan/2 (jq#2207), and @urid format string (jq#2261).
Color configuration

The gojq command automatically disables coloring output when the output is not a tty. To force coloring output, specify --color-output (-C) option. When NO_COLOR environment variable is present or --monochrome-output (-M) option is specified, gojq disables coloring output.

Use GOJQ_COLORS environment variable to configure individual colors. The variable is a colon-separated list of ANSI escape sequences of null, false, true, numbers, strings, object keys, arrays, and objects. The default configuration is 90:33:33:36:32:34;1.

Usage as a library

You can use the gojq parser and interpreter from your Go products.

package main

import (
	"fmt"
	"log"

	"github.com/itchyny/gojq"
)

func main() {
	query, err := gojq.Parse(".foo | ..")
	if err != nil {
		log.Fatalln(err)
	}
	input := map[string]any{"foo": []any{1, 2, 3}}
	iter := query.Run(input) // or query.RunWithContext
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}
}
  • Firstly, use gojq.Parse(string) (*Query, error) to get the query from a string.
  • Secondly, get the result iterator
    • using query.Run or query.RunWithContext
    • or alternatively, compile the query using gojq.Compile and then code.Run or code.RunWithContext. You can reuse the *Code against multiple inputs to avoid compilation of the same query.
    • In either case, you cannot use custom type values as the query input. The type should be []any for an array and map[string]any for a map (just like decoded to an any using the encoding/json package). You can't use []int or map[string]string, for example. If you want to query your custom struct, marshal to JSON, unmarshal to any and use it as the query input.
  • Thirdly, iterate through the results using iter.Next() (any, bool). The iterator can emit an error so make sure to handle it. The method returns true with results, and false when the iterator terminates.
    • The return type is not (any, error) because iterators can emit multiple errors and you can continue after an error. It is difficult for the iterator to tell the termination in this situation.
    • Note that the result iterator may emit infinite number of values; repeat(0) and range(infinite). It may stuck with no output value; def f: f; f. Use RunWithContext when you want to limit the execution time.

gojq.Compile allows to configure the following compiler options.

  • gojq.WithModuleLoader allows to load modules. By default, the module feature is disabled. If you want to load modules from the file system, use gojq.NewModuleLoader.
  • gojq.WithEnvironLoader allows to configure the environment variables referenced by env and $ENV. By default, OS environment variables are not accessible due to security reasons. You can use gojq.WithEnvironLoader(os.Environ) if you want.
  • gojq.WithVariables allows to configure the variables which can be used in the query. Pass the values of the variables to code.Run in the same order.
  • gojq.WithFunction allows to add a custom internal function. An internal function can return a single value (which can be an error) each invocation. To add a jq function (which may include a comma operator to emit multiple values, empty function, accept a filter for its argument, or call another built-in function), use LoadInitModules of the module loader.
  • gojq.WithIterFunction allows to add a custom iterator function. An iterator function returns an iterator to emit multiple values. You cannot define both iterator and non-iterator functions of the same name (with possibly different arities). You can use gojq.NewIter to convert values or an error to a gojq.Iter.
  • gojq.WithInputIter allows to use input and inputs functions. By default, these functions are disabled.

Bug Tracker

Report bug at Issues・itchyny/gojq - GitHub.

Author

itchyny (https://github.com/itchyny)

License

This software is released under the MIT License, see LICENSE.

Documentation

Overview

Package gojq provides the parser and the interpreter of gojq. Please refer to Usage as a library for introduction.

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

func Compare

func Compare(l, r any) int

Compare l and r, and returns jq-flavored comparison value. The result will be 0 if l == r, -1 if l < r, and +1 if l > r. This comparison is used by built-in operators and functions.

func Marshal

func Marshal(v any) ([]byte, error)

Marshal returns the jq-flavored JSON encoding of v.

This method accepts only limited types (nil, bool, int, float64, *big.Int, json.Number, string, []any, and map[string]any) because these are the possible types a gojq iterator can emit. This method marshals NaN to null, truncates infinities to (+|-) math.MaxFloat64, uses \b and \f in strings, and does not escape '<', '>', '&', '\u2028', and '\u2029'. These behaviors are based on the marshaler of jq command, and different from json.Marshal in the Go standard library. Note that the result is not safe to embed in HTML.

func Preview

func Preview(v any) string

Preview returns the preview string of v. The preview string is basically the same as the jq-flavored JSON encoding returned by Marshal, but is truncated by 30 bytes, and more efficient than truncating the result of Marshal.

This method is used by error messages of built-in operators and functions, and accepts only limited types (nil, bool, int, float64, *big.Int, json.Number, string, []any, and map[string]any). Note that the maximum width and trailing strings on truncation may be changed in the future.

func TypeOf

func TypeOf(v any) string

TypeOf returns the jq-flavored type name of v.

This method is used by built-in type/0 function, and accepts only limited types (nil, bool, int, float64, *big.Int, json.Number, string, []any, and map[string]any).

Types

type Array

type Array struct {
	Query *Query
}

Array ...

func (*Array) String

func (e *Array) String() string

type Bind

type Bind struct {
	Patterns []*Pattern
	Body     *Query
}

Bind ...

func (*Bind) String

func (e *Bind) String() string

type Code

type Code struct {
	// contains filtered or unexported fields
}

Code is a compiled jq query.

func Compile

func Compile(q *Query, options ...CompilerOption) (*Code, error)

Compile compiles a query.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse(".[] | .foo")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(query)
	if err != nil {
		log.Fatalln(err)
	}
	iter := code.Run([]any{
		nil,
		"string",
		42,
		[]any{"foo"},
		map[string]any{"foo": 42},
	})
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			fmt.Println(err)
			continue
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

<nil>
expected an object but got: string ("string")
expected an object but got: number (42)
expected an object but got: array (["foo"])
42

func (*Code) Run

func (c *Code) Run(v any, values ...any) Iter

Run runs the code with the variable values (which should be in the same order as the given variables using WithVariables) and returns a result iterator.

It is safe to call this method in goroutines, to reuse a compiled *Code.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse(".foo")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(query)
	if err != nil {
		log.Fatalln(err)
	}
	input := map[string]any{"foo": 42}
	iter := code.Run(input)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

42

func (*Code) RunWithContext

func (c *Code) RunWithContext(ctx context.Context, v any, values ...any) Iter

RunWithContext runs the code with context.

Example
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse("def f: f; f, f")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(query)
	if err != nil {
		log.Fatalln(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()
	iter := code.RunWithContext(ctx, nil)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			fmt.Println(err)
			continue
		}
		_ = v
	}

}
Output:

context deadline exceeded

type CompilerOption

type CompilerOption func(*compiler)

CompilerOption is a compiler option.

func WithEnvironLoader

func WithEnvironLoader(environLoader func() []string) CompilerOption

WithEnvironLoader is a compiler option for environment variables loader. The OS environment variables are not accessible by default due to security reasons. You can specify os.Environ as argument if you allow to access.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse("env | keys[]")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithEnvironLoader(func() []string {
			return []string{"foo=42", "bar=128"}
		}),
	)
	if err != nil {
		log.Fatalln(err)
	}
	iter := code.Run(nil)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

"bar"
"foo"

func WithFunction

func WithFunction(name string, minarity, maxarity int, f func(context.Context, any, []any) any) CompilerOption

WithFunction is a compiler option for adding a custom internal function. Specify the minimum and maximum count of the function arguments. These values should satisfy 0 <= minarity <= maxarity <= 30, otherwise panics. On handling numbers, take account to int, float64, *big.Int, and json.Number. These are the number types you are allowed to return, so do not return int64. Refer to ValueError to return a value error just like built-in error function. If you want to emit multiple values, call the empty function, accept a filter for its argument, or call another built-in function, then use LoadInitModules of the module loader.

Example
package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"math/big"
	"strconv"

	"github.com/Sosivio/gojq"
)

func toFloat(x any) (float64, bool) {
	switch x := x.(type) {
	case int:
		return float64(x), true
	case float64:
		return x, true
	case *big.Int:
		f, err := strconv.ParseFloat(x.String(), 64)
		return f, err == nil
	case json.Number:
		f, err := x.Float64()
		return f, err == nil
	default:
		return 0.0, false
	}
}

func main() {
	query, err := gojq.Parse(".[] | f | f(3)")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithFunction("f", 0, 1, func(_ context.Context, x any, xs []any) any {
			if x, ok := toFloat(x); ok {
				if len(xs) == 1 {
					if y, ok := toFloat(xs[0]); ok {
						x *= y
					} else {
						return fmt.Errorf("f cannot be applied to: %v, %v", x, xs)
					}
				} else {
					x += 2
				}
				return x
			}
			return fmt.Errorf("f cannot be applied to: %v, %v", x, xs)
		}),
	)
	if err != nil {
		log.Fatalln(err)
	}
	input := []any{0, 1, 2.5, json.Number("10000000000000000000000000000000000000000")}
	iter := code.Run(input)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

6
9
13.5
3e+40

func WithInputIter

func WithInputIter(inputIter Iter) CompilerOption

WithInputIter is a compiler option for input iterator used by input(s)/0. Note that input and inputs functions are not allowed by default. We have to distinguish the query input and the values for input(s) functions. For example, consider using inputs with --null-input. If you want to allow input(s) functions, create an Iter and use WithInputIter option.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse("reduce inputs as $x (0; . + $x)")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithInputIter(gojq.NewIter(1, 2, 3, 4, 5)),
	)
	if err != nil {
		log.Fatalln(err)
	}
	iter := code.Run(nil)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

15

func WithIterFunction

func WithIterFunction(name string, minarity, maxarity int, f func(context.Context, any, []any) Iter) CompilerOption

WithIterFunction is a compiler option for adding a custom iterator function. This is like the WithFunction option, but you can add a function which returns an Iter to emit multiple values. You cannot define both iterator and non-iterator functions of the same name (with possibly different arities). See also NewIter, which can be used to convert values or an error to an Iter.

Example
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

// Implementation of range/2 using WithIterFunction option.
type rangeIter struct {
	value, max int
}

func (iter *rangeIter) Next() (any, bool) {
	if iter.value >= iter.max {
		return nil, false
	}
	v := iter.value
	iter.value++
	return v, true
}

func main() {
	query, err := gojq.Parse("f(3; 7)")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithIterFunction("f", 2, 2, func(_ context.Context, _ any, xs []any) gojq.Iter {
			if x, ok := xs[0].(int); ok {
				if y, ok := xs[1].(int); ok {
					return &rangeIter{x, y}
				}
			}
			return gojq.NewIter(fmt.Errorf("f cannot be applied to: %v", xs))
		}),
	)
	if err != nil {
		log.Fatalln(err)
	}
	iter := code.Run(nil)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

3
4
5
6

func WithModuleLoader

func WithModuleLoader(moduleLoader ModuleLoader) CompilerOption

WithModuleLoader is a compiler option for module loader. If you want to load modules from the filesystem, use NewModuleLoader.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

type moduleLoader struct{}

func (*moduleLoader) LoadModule(name string) (*gojq.Query, error) {
	switch name {
	case "module1":
		return gojq.Parse(`
			module { name: "module1", test: 42 };
			import "module2" as foo;
			def g: foo::f;
		`)
	case "module2":
		return gojq.Parse(`
			def f: .foo;
		`)
	case "module3":
		return gojq.Parse("")
	}
	return nil, fmt.Errorf("module not found: %q", name)
}

func main() {
	query, err := gojq.Parse(`
		import "module1" as m;
		m::g
	`)
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithModuleLoader(&moduleLoader{}),
	)
	if err != nil {
		log.Fatalln(err)
	}
	input := map[string]any{"foo": 42}
	iter := code.Run(input)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

42

func WithVariables

func WithVariables(variables []string) CompilerOption

WithVariables is a compiler option for variable names. The variables can be used in the query. You have to give the values to *Code.Run in the same order.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse("$x * 100 + $y, $z")
	if err != nil {
		log.Fatalln(err)
	}
	code, err := gojq.Compile(
		query,
		gojq.WithVariables([]string{
			"$x", "$y", "$z",
		}),
	)
	if err != nil {
		log.Fatalln(err)
	}
	iter := code.Run(nil, 12, 42, 128)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

1242
128

type ConstArray

type ConstArray struct {
	Elems []*ConstTerm
}

ConstArray ...

func (*ConstArray) String

func (e *ConstArray) String() string

type ConstObject

type ConstObject struct {
	KeyVals []*ConstObjectKeyVal
}

ConstObject ...

func (*ConstObject) String

func (e *ConstObject) String() string

func (*ConstObject) ToValue

func (e *ConstObject) ToValue() map[string]any

ToValue converts the object to map[string]any.

type ConstObjectKeyVal

type ConstObjectKeyVal struct {
	Key       string
	KeyString string
	Val       *ConstTerm
}

ConstObjectKeyVal ...

func (*ConstObjectKeyVal) String

func (e *ConstObjectKeyVal) String() string

type ConstTerm

type ConstTerm struct {
	Object *ConstObject
	Array  *ConstArray
	Number string
	Str    string
	Null   bool
	True   bool
	False  bool
}

ConstTerm ...

func (*ConstTerm) String

func (e *ConstTerm) String() string

type Foreach

type Foreach struct {
	Term    *Term
	Pattern *Pattern
	Start   *Query
	Update  *Query
	Extract *Query
}

Foreach ...

func (*Foreach) String

func (e *Foreach) String() string

type Func

type Func struct {
	Name string
	Args []*Query
}

Func ...

func (*Func) String

func (e *Func) String() string

type FuncDef

type FuncDef struct {
	Name string
	Args []string
	Body *Query
}

FuncDef ...

func (*FuncDef) Minify

func (e *FuncDef) Minify()

Minify ...

func (*FuncDef) String

func (e *FuncDef) String() string

type If

type If struct {
	Cond *Query
	Then *Query
	Elif []*IfElif
	Else *Query
}

If ...

func (*If) String

func (e *If) String() string

type IfElif

type IfElif struct {
	Cond *Query
	Then *Query
}

IfElif ...

func (*IfElif) String

func (e *IfElif) String() string

type Import

type Import struct {
	ImportPath  string
	ImportAlias string
	IncludePath string
	Meta        *ConstObject
}

Import ...

func (*Import) String

func (e *Import) String() string

type Index

type Index struct {
	Name    string
	Str     *String
	Start   *Query
	End     *Query
	IsSlice bool
}

Index ...

func (*Index) String

func (e *Index) String() string

type Iter

type Iter interface {
	Next() (any, bool)
}

Iter is an interface for an iterator.

func NewIter

func NewIter(values ...any) Iter

NewIter creates a new Iter from values.

type Label

type Label struct {
	Ident string
	Body  *Query
}

Label ...

func (*Label) String

func (e *Label) String() string

type ModuleLoader

type ModuleLoader any

ModuleLoader is the interface for loading modules.

Implement following optional methods. Use NewModuleLoader to load local modules.

LoadModule(string) (*Query, error)
LoadModuleWithMeta(string, map[string]any) (*Query, error)
LoadInitModules() ([]*Query, error)
LoadJSON(string) (any, error)
LoadJSONWithMeta(string, map[string]any) (any, error)

func NewModuleLoader

func NewModuleLoader(paths []string) ModuleLoader

NewModuleLoader creates a new ModuleLoader reading local modules in the paths.

type Object

type Object struct {
	KeyVals []*ObjectKeyVal
}

Object ...

func (*Object) String

func (e *Object) String() string

type ObjectKeyVal

type ObjectKeyVal struct {
	Key       string
	KeyString *String
	KeyQuery  *Query
	Val       *ObjectVal
}

ObjectKeyVal ...

func (*ObjectKeyVal) String

func (e *ObjectKeyVal) String() string

type ObjectVal

type ObjectVal struct {
	Queries []*Query
}

ObjectVal ...

func (*ObjectVal) String

func (e *ObjectVal) String() string

type Operator

type Operator int

Operator ...

const (
	OpPipe Operator = iota + 1
	OpComma
	OpAdd
	OpSub
	OpMul
	OpDiv
	OpMod
	OpEq
	OpNe
	OpGt
	OpLt
	OpGe
	OpLe
	OpAnd
	OpOr
	OpAlt
	OpAssign
	OpModify
	OpUpdateAdd
	OpUpdateSub
	OpUpdateMul
	OpUpdateDiv
	OpUpdateMod
	OpUpdateAlt
)

Operators ...

func (Operator) GoString

func (op Operator) GoString() (str string)

GoString implements fmt.GoStringer.

func (Operator) String

func (op Operator) String() string

String implements fmt.Stringer.

type Pattern

type Pattern struct {
	Name   string
	Array  []*Pattern
	Object []*PatternObject
}

Pattern ...

func (*Pattern) String

func (e *Pattern) String() string

type PatternObject

type PatternObject struct {
	Key       string
	KeyString *String
	KeyQuery  *Query
	Val       *Pattern
}

PatternObject ...

func (*PatternObject) String

func (e *PatternObject) String() string

type Query

type Query struct {
	Meta     *ConstObject
	Imports  []*Import
	FuncDefs []*FuncDef
	Term     *Term
	Left     *Query
	Op       Operator
	Right    *Query
	Func     string
}

Query represents the abstract syntax tree of a jq query.

func Parse

func Parse(src string) (*Query, error)

func (*Query) Run

func (e *Query) Run(v any) Iter

Run the query.

It is safe to call this method in goroutines, to reuse a parsed *Query.

Example
package main

import (
	"fmt"
	"log"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse(".foo | ..")
	if err != nil {
		log.Fatalln(err)
	}
	input := map[string]any{"foo": []any{1, 2, 3}}
	iter := query.Run(input)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			log.Fatalln(err)
		}
		fmt.Printf("%#v\n", v)
	}

}
Output:

[]interface {}{1, 2, 3}
1
2
3

func (*Query) RunWithContext

func (e *Query) RunWithContext(ctx context.Context, v any) Iter

RunWithContext runs the query with context.

Example
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/Sosivio/gojq"
)

func main() {
	query, err := gojq.Parse("def f: f; f, f")
	if err != nil {
		log.Fatalln(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()
	iter := query.RunWithContext(ctx, nil)
	for {
		v, ok := iter.Next()
		if !ok {
			break
		}
		if err, ok := v.(error); ok {
			fmt.Println(err)
			continue
		}
		_ = v
	}

}
Output:

context deadline exceeded

func (*Query) String

func (e *Query) String() string

type Reduce

type Reduce struct {
	Term    *Term
	Pattern *Pattern
	Start   *Query
	Update  *Query
}

Reduce ...

func (*Reduce) String

func (e *Reduce) String() string

type String

type String struct {
	Str     string
	Queries []*Query
}

String ...

func (*String) String

func (e *String) String() string

type Suffix

type Suffix struct {
	Index    *Index
	Iter     bool
	Optional bool
	Bind     *Bind
}

Suffix ...

func (*Suffix) String

func (e *Suffix) String() string

type Term

type Term struct {
	Type       TermType
	Index      *Index
	Func       *Func
	Object     *Object
	Array      *Array
	Number     string
	Unary      *Unary
	Format     string
	Str        *String
	If         *If
	Try        *Try
	Reduce     *Reduce
	Foreach    *Foreach
	Label      *Label
	Break      string
	Query      *Query
	SuffixList []*Suffix
}

Term ...

func (*Term) String

func (e *Term) String() string

type TermType

type TermType int

TermType represents the type of Term.

const (
	TermTypeIdentity TermType = iota + 1
	TermTypeRecurse
	TermTypeNull
	TermTypeTrue
	TermTypeFalse
	TermTypeIndex
	TermTypeFunc
	TermTypeObject
	TermTypeArray
	TermTypeNumber
	TermTypeUnary
	TermTypeFormat
	TermTypeString
	TermTypeIf
	TermTypeTry
	TermTypeReduce
	TermTypeForeach
	TermTypeLabel
	TermTypeBreak
	TermTypeQuery
)

TermType list.

func (TermType) GoString

func (termType TermType) GoString() (str string)

GoString implements fmt.GoStringer.

type Try

type Try struct {
	Body  *Query
	Catch *Query
}

Try ...

func (*Try) String

func (e *Try) String() string

type Unary

type Unary struct {
	Op   Operator
	Term *Term
}

Unary ...

func (*Unary) String

func (e *Unary) String() string

type ValueError

type ValueError interface {
	error
	Value() any
}

ValueError is an interface for errors with a value for internal function. Return an error implementing this interface when you want to catch error values (not error messages) by try-catch, just like built-in error function. Refer to WithFunction to add a custom internal function.

Directories

Path Synopsis
Package cli implements the gojq command.
Package cli implements the gojq command.
cmd
gojq
gojq - Go implementation of jq
gojq - Go implementation of jq

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