textreplace

Documentation

Index

• func CopyWithFrames(src io.Reader, dst io.Writer, buf []byte, overlapSize int, ...) (written int64, err error)
• func InPlaceReplace(s, old, new []byte, n int) (err error)
• func InPlaceReplaceAll(s, old, new []byte) (err error)
• func ReplaceBytes(src io.Reader, dst io.Writer, old []byte, new []byte) (written int64, err error)
• func ReplaceStringsPrefix(source io.Reader, output io.Writer, values []string, old string, new string) (replacements int, matches map[string]struct{}, err error)
• type ErrNotSameLength
  • func (e ErrNotSameLength) Error() string

Examples

• CopyWithFrames
• ReplaceStringsPrefix

Functions

func CopyWithFrames

func CopyWithFrames(src io.Reader, dst io.Writer, buf []byte, overlapSize int, transform func(b []byte) error) (
	written int64, err error)

CopyWithFrames copies data between two sources. As data is copied it is loaded into a byte buffer that overlaps with the previous buffer. This ensures that bytes of a certain width will not be split over the boundary of a frame.

Example

// We'd like to replace "dolor" with "fishy" in this text
lorem := []byte("Lorem ipsum dolor sit amet")

// With a buffer size of 15 we would split the input into
// []byte("Lorem ipsum dol") and []byte("or sit amet")
// and miss the opportunity to replace "dolor"
bufferSize := 15
expectedAnswer := bytes.ReplaceAll(lorem, []byte("dolor"), []byte("fishy"))
source := bytes.NewBuffer(lorem)

out := bytes.Buffer{}

// if we set an overlap size of 5 we'll ensure we see all length 5 segments of text
_, _ = CopyWithFrames(source, &out, make([]byte, bufferSize), 5, func(b []byte) error {
	fmt.Println(string(b))
	copy(b, bytes.ReplaceAll(b, []byte("dolor"), []byte("fishy")))
	return nil
})
fmt.Println(bytes.Equal(out.Bytes(), expectedAnswer))

Output:

Lorem ipsu
 ipsum dolor si
hy sit amety si
true

func InPlaceReplace

func InPlaceReplace(s, old, new []byte, n int) (err error)

func InPlaceReplaceAll

func InPlaceReplaceAll(s, old, new []byte) (err error)

func ReplaceBytes

func ReplaceBytes(src io.Reader, dst io.Writer, old []byte, new []byte) (written int64, err error)

func ReplaceStringsPrefix

func ReplaceStringsPrefix(source io.Reader, output io.Writer, values []string, old string, new string) (
	replacements int, matches map[string]struct{}, err error)

ReplaceStringsPrefix replaces the prefix of matching strings in a byte stream. All values to be replaced must have the same prefix and that prefix must be the same length as the new value.

Example

var output bytes.Buffer
_, _, _ = ReplaceStringsPrefix(
	bytes.NewBuffer([]byte(
		"something/nix/store/zziylsdvcqgwwwhbspf1agbz0vldxjr3-perl5.30.2-JSON-4.02something"),
	),
	&output,
	[]string{"/nix/store/zziylsdvcqgwwwhbspf1agbz0vldxjr3-perl5.30.2-JSON-4.02"},
	"/nix/store/",
	"/tmp/wings/",
)

fmt.Println(output.String())

Output:

something/tmp/wings/zziylsdvcqgwwwhbspf1agbz0vldxjr3-perl5.30.2-JSON-4.02something

Types

type ErrNotSameLength

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

func (ErrNotSameLength) Error

func (e ErrNotSameLength) Error() string