replace

README

Streaming text replacement

This package provides a x/text/transform.Transformer implementation that replaces text

Example

package main

import (
	"io"
	"os"
	"regexp"

	"github.com/icholy/replace"
	"golang.org/x/text/transform"
)

func main() {
	f, _ := os.Open("file")
	defer f.Close()

	r := transform.NewReader(f, transform.Chain(
		// simple replace
		replace.String("foo", "bar"),
		replace.Bytes([]byte("thing"), []byte("test")),

		// remove all words that start with baz
		replace.Regexp(regexp.MustCompile(`baz\w*`), nil),

		// increment all numbers
		replace.RegexpStringFunc(regexp.MustCompile(`\d+`), func(match string) string {
			x, _ := strconv.Atoi(match)
			return strconv.Itoa(x+1)
		}),
	))

	_, _ = io.Copy(os.Stdout, r)
}

Notes Regexp* functions

• The replace functions should not save or modify any []byte parameters they recieve.
• For better performance, reduce the MaxSourceBuffer size to the largest possible match (Default 64kb).
• If a match is longer than MaxSourceBuffer it may be skipped.

Documentation

Index

• type RegexpTransformer
  • func Regexp(re *regexp.Regexp, new []byte) *RegexpTransformer
  • func RegexpFunc(re *regexp.Regexp, replace func([]byte) []byte) *RegexpTransformer
  • func RegexpIndexFunc(re *regexp.Regexp, replace func(src []byte, index []int) []byte) *RegexpTransformer
  • func RegexpString(re *regexp.Regexp, new string) *RegexpTransformer
  • func RegexpStringFunc(re *regexp.Regexp, replace func(string) string) *RegexpTransformer
  • func RegexpStringSubmatchFunc(re *regexp.Regexp, replace func([]string) string) *RegexpTransformer
  • func RegexpSubmatchFunc(re *regexp.Regexp, replace func([][]byte) []byte) *RegexpTransformer
  • func (t *RegexpTransformer) Reset()
  • func (t *RegexpTransformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)
• type Transformer
  • func Bytes(old, new []byte) Transformer
  • func String(old, new string) Transformer
  • func (t Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)

Types

type RegexpTransformer

type RegexpTransformer struct {
	// MaxSourceBuffer is the maximum size of the window used to search for the
	// regex match. (Default is 64kb).
	MaxSourceBuffer int
	// contains filtered or unexported fields
}

RegexpTransformer replaces regexp matches in a stream See: http://golang.org/x/text/transform

func Regexp

func Regexp(re *regexp.Regexp, new []byte) *RegexpTransformer

Regexp returns a transformer that replaces all matches of re with new

func RegexpFunc

func RegexpFunc(re *regexp.Regexp, replace func([]byte) []byte) *RegexpTransformer

RegexpFunc returns a transformer that replaces all matches of re with the result of calling replace with the match. The []byte parameter passed to replace should not be modified and is not guaranteed to be valid after the function returns.

func RegexpIndexFunc

func RegexpIndexFunc(re *regexp.Regexp, replace func(src []byte, index []int) []byte) *RegexpTransformer

RegexpIndexFunc returns a transformer that replaces all matches of re with the return value of replace. The replace function recieves the underlying src buffer and indexes into that buffer. The []byte parameter passed to replace should not be modified and is not guaranteed to be valid after the function returns.

func RegexpString

func RegexpString(re *regexp.Regexp, new string) *RegexpTransformer

RegexpString returns a transformer that replaces all matches of re with new

func RegexpStringFunc

func RegexpStringFunc(re *regexp.Regexp, replace func(string) string) *RegexpTransformer

RegexpStringFunc returns a transformer that replaces all matches of re with the result of calling replace with the match.

func RegexpStringSubmatchFunc

func RegexpStringSubmatchFunc(re *regexp.Regexp, replace func([]string) string) *RegexpTransformer

RegexpStringSubmatchFunc returns a transformer that replaces all matches of re with the result of calling replace with the submatch.

func RegexpSubmatchFunc

func RegexpSubmatchFunc(re *regexp.Regexp, replace func([][]byte) []byte) *RegexpTransformer

RegexpSubmatchFunc returns a transformer that replaces all matches of re with the result of calling replace with the submatch. The [][]byte parameter passed to replace should not be modified and is not guaranteed to be valid after the function returns.

func (*RegexpTransformer) Reset

func (t *RegexpTransformer) Reset()

Reset resets the state and allows a Transformer to be reused.

func (*RegexpTransformer) Transform

func (t *RegexpTransformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)

Transform implements golang.org/x/text/transform#Transformer

type Transformer

type Transformer struct {
	transform.NopResetter
	// contains filtered or unexported fields
}

Transformer replaces text in a stream See: http://golang.org/x/text/transform

func Bytes

func Bytes(old, new []byte) Transformer

Bytes returns a transformer that replaces all instances of old with new. Unlike bytes.Replace, empty old values don't match anything.

func String

func String(old, new string) Transformer

String returns a transformer that replaces all instances of old with new. Unlike strings.Replace, empty old values don't match anything.

func (Transformer) Transform

func (t Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)

Transform implements golang.org/x/text/transform#Transformer