runes - ActiveState ActiveGo 1.8
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Package runes

import "golang.org/x/text/runes"
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Overview ▾

Package runes provide transforms for UTF-8 encoded text.

type Set

A Set is a collection of runes. 

type Set interface {
    // Contains returns true if r is contained in the set.
    Contains(r rune) bool
}

func In 

func In(rt *unicode.RangeTable) Set

In creates a Set with a Contains method that returns true for all runes in the given RangeTable.

▾ Example

Code:

// Convert Latin characters to their canonical form, while keeping other
// width distinctions.
t := runes.If(runes.In(unicode.Latin), width.Fold, nil)
s, _, _ := transform.String(t, "ｱﾙｱﾉﾘｳ tech / アルアノリウ ｔｅｃｈ")
fmt.Println(s)

Output:

ｱﾙｱﾉﾘｳ tech / アルアノリウ tech

func NotIn 

func NotIn(rt *unicode.RangeTable) Set

In creates a Set with a Contains method that returns true for all runes not in the given RangeTable.

func Predicate 

func Predicate(f func(rune) bool) Set

Predicate creates a Set with a Contains method that returns f(r).

type Transformer

Transformer implements the transform.Transformer interface. 

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

func If 

func If(s Set, tIn, tNotIn transform.Transformer) Transformer

If returns a transformer that applies tIn to consecutive runes for which s.Contains(r) and tNotIn to consecutive runes for which !s.Contains(r). Reset is called on tIn and tNotIn at the start of each run. A Nop transformer will substitute a nil value passed to tIn or tNotIn. Invalid UTF-8 is translated to RuneError to determine which transformer to apply, but is passed as is to the respective transformer.

▾ Example

Code:

// Widen everything but ASCII.
isASCII := func(r rune) bool { return r <= unicode.MaxASCII }
t := runes.If(runes.Predicate(isASCII), nil, width.Widen)
s, _, _ := transform.String(t, "ｱﾙｱﾉﾘｳ tech / 中國 / 5₩")
fmt.Println(s)

Output:

アルアノリウ tech / 中國 / 5￦

func Map 

func Map(mapping func(rune) rune) Transformer

Map returns a Transformer that maps the runes in the input using the given mapping. Illegal bytes in the input are converted to utf8.RuneError before being passed to the mapping func.

▾ Example

Code:

replaceHyphens := runes.Map(func(r rune) rune {
    if unicode.Is(unicode.Hyphen, r) {
        return '|'
    }
    return r
})
s, _, _ := transform.String(replaceHyphens, "a-b‐c⸗d﹣e")
fmt.Println(s)

Output:

a|b|c|d|e

func Remove 

func Remove(s Set) Transformer

Remove returns a Transformer that removes runes r for which s.Contains(r). Illegal input bytes are replaced by RuneError before being passed to f.

▾ Example

Code:

t := transform.Chain(norm.NFD, runes.Remove(runes.In(unicode.Mn)), norm.NFC)
s, _, _ := transform.String(t, "résumé")
fmt.Println(s)

Output:

resume

func ReplaceIllFormed 

func ReplaceIllFormed() Transformer

ReplaceIllFormed returns a transformer that replaces all input bytes that are not part of a well-formed UTF-8 code sequence with utf8.RuneError.

func (Transformer) Bytes 

func (t Transformer) Bytes(b []byte) []byte

Bytes returns a new byte slice with the result of converting b using t. It calls Reset on t. It returns nil if any error was found. This can only happen if an error-producing Transformer is passed to If.

func (Transformer) Reset 

func (t Transformer) Reset()

func (Transformer) Span 

func (t Transformer) Span(b []byte, atEOF bool) (n int, err error)

func (Transformer) String 

func (t Transformer) String(s string) string

String returns a string with the result of converting s using t. It calls Reset on t. It returns the empty string if any error was found. This can only happen if an error-producing Transformer is passed to If.

func (Transformer) Transform 

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