grepr

README

Missing feature of the standard library: printing arbitrary inputs as Go code, with proper spacing and support for multi-line output with indentation. The name "repr" stands for "representation" and alludes to the Python function with the same name.

API doc: https://pkg.go.dev/github.com/mitranim/gg/grepr

Example:

package mock

import (
  "fmt"

  "github.com/mitranim/gg"
  "github.com/mitranim/gg/grepr"
)

type Outer struct {
  OuterId   int
  OuterName string
  Embed
  Inner *Inner
}

type Embed struct {
  EmbedId   int
  EmbedName string
}

type Inner struct {
  InnerId   *int
  InnerName *string
}

func main() {
  fmt.Println(grepr.String(Outer{
    OuterName: `outer`,
    Embed:     Embed{EmbedId: 20},
    Inner:     &Inner{
      InnerId:   gg.Ptr(30),
      InnerName: gg.Ptr(`inner`),
    },
  }))

  /**
  mock.Outer{
    OuterName: `outer`,
    Embed: mock.Embed{EmbedId: 20},
    Inner: &mock.Inner{
      InnerId: gg.Ptr(30),
      InnerName: gg.Ptr(`inner`),
    },
  }
  */
}

Documentation

Overview

Missing feature of the standard library: printing arbitrary inputs as Go code, with proper spacing and support for multi-line output with indentation. The name "repr" stands for "representation" and alludes to the Python function with the same name.

Index

• Variables
• func CanBackquote[A gg.Text](src A) bool
• func Println(src any)
• func Prn(desc string, src any)
• func String(src any) string
• func StringIndent(src any, lvl int) string
• type Conf
  • func (self Conf) AnyString(src any) string
  • func (self Conf) Fmt() Fmt
  • func (self Conf) IsMulti() bool
  • func (self Conf) IsSingle() bool
  • func (self Conf) Println(src any)
  • func (self Conf) Prn(desc string, src any)
  • func (self Conf) SkipZeroFields() bool
  • func (self Conf) ValueString(src r.Value) string
• type Fmt
  • func (self *Fmt) Any(src any)
  • func (self *Fmt) Value(src r.Value)

Examples

• String

Variables

var ConfDefault = Conf{Indent: gg.Indent}

Default config used by top-level formatting functions in this package.

var ConfFull = Conf{Indent: gg.Indent, ZeroFields: true}

Config that allows formatting of struct zero fields.

Functions

func CanBackquote

func CanBackquote[A gg.Text](src A) bool

Corrected version of `strconv.CanBackquote` that allows newlines.

func Println

func Println(src any)

Shortcut for printing the input as Go code, using the default config.

func Prn

func Prn(desc string, src any)

Shortcut for printing the input as Go code, prefixed with the given description, using the default config. Handy for debug-printing.

func String

func String(src any) string

Similar to `fmt.Sprintf("%#v")` or `gg.GoString`, but more advanced. Formats the input as Go code, using the config `ConfDefault`.

Example

package main

import (
	"fmt"

	"github.com/mitranim/gg"
	"github.com/mitranim/gg/grepr"
)

type Outer struct {
	OuterId   int
	OuterName string
	Embed
	Inner *Inner
}

type Embed struct {
	EmbedId   int
	EmbedName string
}

type Inner struct {
	InnerId   *int
	InnerName *string
}

var testInner = Inner{
	InnerId:   gg.Ptr(30),
	InnerName: gg.Ptr(`inner`),
}

var testEmbed = Embed{EmbedId: 20}

var testOuter = Outer{
	OuterName: `outer`,
	Embed:     testEmbed,
	Inner:     &testInner,
}

func main() {
	fmt.Println(grepr.String(testOuter))
}

Output:

grepr_test.Outer{
    OuterName: `outer`,
    Embed: grepr_test.Embed{EmbedId: 20},
    Inner: &grepr_test.Inner{
        InnerId: gg.Ptr(30),
        InnerName: gg.Ptr(`inner`),
    },
}

func StringIndent

func StringIndent(src any, lvl int) string

Formats the input as Go code, using the default config with the given indentation level.

Types

type Conf

type Conf struct {
	Indent     string
	ZeroFields bool
}

Formatting config.

• `.Indent` controls indentation. If empty, output is single line.
• `.ZeroFields`, if set, forces printing of zero fields in structs. By default zero fields are skipped.

var ConfZero Conf

Empty config for single-line formatting. Note that multi-line strings may still lead to multi-line output. This may change in the future.

func (Conf) AnyString

func (self Conf) AnyString(src any) string

Shortcut for using this config to format the input as Go code.

func (Conf) Fmt

func (self Conf) Fmt() Fmt

Shortcut for creating a pretty-formatter with this config.

func (Conf) IsMulti

func (self Conf) IsMulti() bool

Short for "is multi line". Inverse of `.IsSingle`.

func (Conf) IsSingle

func (self Conf) IsSingle() bool

Short for "is single line". If `.Indent` is empty, this is true, and output is single-line. Otherwise output is multi-line.

func (Conf) Println

func (self Conf) Println(src any)

Shortcut for printing the input as Go code, using this config

func (Conf) Prn

func (self Conf) Prn(desc string, src any)

Shortcut for printing the input as Go code, using this config, prefixed with the given description. Handy for debug-printing.

func (Conf) SkipZeroFields

func (self Conf) SkipZeroFields() bool

Inverse of `.ZeroFields`.

func (Conf) ValueString

func (self Conf) ValueString(src r.Value) string

Shortcut for using this config to format the input as Go code.

type Fmt

type Fmt struct {
	Conf
	gg.Buf
	Lvl       int
	ElideType bool
	Visited   gg.Set[u.Pointer]
}

Short for "formatter".

func (*Fmt) Any

func (self *Fmt) Any(src any)

Formats the input into the inner buffer, using the inner config.

func (*Fmt) Value

func (self *Fmt) Value(src r.Value)

Formats the input into the inner buffer, using the inner config.