Example:
PACKAGE
package utf8
import "unicode/utf8"
Package utf8 implements functions and constants to support text
encoded in UTF-8. This package calls a Unicode character a rune for
brevity.
CONSTANTS
const (
RuneError = unicode.ReplacementChar // the "error" Rune or "replacement character".
RuneSelf = 0x80 // characters below Runeself are represented as themselves in a single byte.
UTFMax = 4 // maximum number of bytes of a UTF-8 encoded Unicode character.
)
Numbers fundamental to the encoding.
FUNCTIONS
func DecodeLastRune(p []byte) (r rune, size int)
DecodeLastRune unpacks the last UTF-8 encoding in p and returns the
rune and its width in bytes.
func DecodeLastRuneInString(s string) (r rune, size int)
DecodeLastRuneInString is like DecodeLastRune but its input is a
string.
func DecodeRune(p []byte) (r rune, size int)
DecodeRune unpacks the first UTF-8 encoding in p and returns the rune
and its width in bytes.
func DecodeRuneInString(s string) (r rune, size int)
DecodeRuneInString is like DecodeRune but its input is a string.
func EncodeRune(p []byte, r rune) int
EncodeRune writes into p (which must be large enough) the UTF-8
encoding of the rune. It returns the number of bytes written.
func FullRune(p []byte) bool
FullRune reports whether the bytes in p begin with a full UTF-8
encoding of a rune. An invalid encoding is considered a full Rune
since it will convert as a width-1 error rune.
func FullRuneInString(s string) bool
FullRuneInString is like FullRune but its input is a string.
func RuneCount(p []byte) int
RuneCount returns the number of runes in p. Erroneous and short
encodings are treated as single runes of width 1 byte.
func RuneCountInString(s string) (n int)
RuneCountInString is like RuneCount but its input is a string.
func RuneLen(r rune) int
RuneLen returns the number of bytes required to encode the rune.
func RuneStart(b byte) bool
RuneStart reports whether the byte could be the first byte of an
encoded rune. Second and subsequent bytes always have the top two
bits set to 10.
func Valid(p []byte) bool
Valid reports whether p consists entirely of valid UTF-8-encoded
runes.
func ValidString(s string) bool
ValidString reports whether s consists entirely of valid UTF-8-encoded
runes.
TYPES
type String struct {
// contains filtered or unexported fields
}
String wraps a regular string with a small structure that provides
more efficient indexing by code point index, as opposed to byte index.
Scanning incrementally forwards or backwards is O(1) per index
operation (although not as fast a range clause going forwards).
Random access is O(N) in the length of the string, but the overhead is
less than always scanning from the beginning. If the string is ASCII,
random access is O(1). Unlike the built-in string type, String has
internal mutable state and is not thread-safe.
func NewString(contents string) *String
NewString returns a new UTF-8 string with the provided contents.
func (s *String) At(i int) rune
At returns the rune with index i in the String. The sequence of runes
is the same as iterating over the contents with a "for range" clause.
func (s *String) Init(contents string) *String
Init initializes an existing String to hold the provided contents.
It returns a pointer to the initialized String.
func (s *String) IsASCII() bool
IsASCII returns a boolean indicating whether the String contains only
ASCII bytes.
func (s *String) RuneCount() int
RuneCount returns the number of runes (Unicode code points) in the
String.
func (s *String) Slice(i, j int) string
Slice returns the string sliced at rune positions [i:j].
func (s *String) String() string
String returns the contents of the String. This method also means the
String is directly printable by fmt.Print.
Fixes#2479.
R=golang-dev, dsymonds, mattn.jp, r, gri, r
CC=golang-dev
https://golang.org/cl/5472051
don't crash when printing error messages about symbols in a garbled state.
render OCOMPLIT in export mode.
R=rsc
CC=golang-dev
https://golang.org/cl/5466045
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.
The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.
For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.
R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
Also, clarify when interface comparison panics and
that comparison to nil is a special syntax rather than
a general comparison rule.
R=r, gri, r, iant, cw, bradfitz
CC=golang-dev
https://golang.org/cl/5440117
I had to move readFile into sys_$GOOS.go
since syscall.Open takes only two arguments
on Plan 9.
R=lucio.dere, rsc, alex.brainman
CC=golang-dev
https://golang.org/cl/5447061
Made te and td arrays into variables te0-3 and td0-3,
which improves performance from 7000ns/op to 5800.
R=rsc, rogpeppe, agl
CC=golang-dev
https://golang.org/cl/5449077
src/clean.bash:
Add clean-ups for previously overlooked directories.
doc/codelab/wiki/Makefile:
Dropped "index.html" from CLEANFILES so it will not be
deleted on cleaning.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5476050
