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path: root/src/pkg/utf8/utf8.go
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Diffstat (limited to 'src/pkg/utf8/utf8.go')
-rw-r--r--src/pkg/utf8/utf8.go150
1 files changed, 75 insertions, 75 deletions
diff --git a/src/pkg/utf8/utf8.go b/src/pkg/utf8/utf8.go
index ad78f599c..8e373e32d 100644
--- a/src/pkg/utf8/utf8.go
+++ b/src/pkg/utf8/utf8.go
@@ -6,40 +6,40 @@
// This package calls a Unicode character a rune for brevity.
package utf8
-import "unicode" // only needed for a couple of constants
+import "unicode" // only needed for a couple of constants
// Numbers fundamental to the encoding.
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.
+ 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.
)
const (
- _T1 = 0x00; // 0000 0000
- _Tx = 0x80; // 1000 0000
- _T2 = 0xC0; // 1100 0000
- _T3 = 0xE0; // 1110 0000
- _T4 = 0xF0; // 1111 0000
- _T5 = 0xF8; // 1111 1000
-
- _Maskx = 0x3F; // 0011 1111
- _Mask2 = 0x1F; // 0001 1111
- _Mask3 = 0x0F; // 0000 1111
- _Mask4 = 0x07; // 0000 0111
-
- _Rune1Max = 1<<7 - 1;
- _Rune2Max = 1<<11 - 1;
- _Rune3Max = 1<<16 - 1;
- _Rune4Max = 1<<21 - 1;
+ _T1 = 0x00 // 0000 0000
+ _Tx = 0x80 // 1000 0000
+ _T2 = 0xC0 // 1100 0000
+ _T3 = 0xE0 // 1110 0000
+ _T4 = 0xF0 // 1111 0000
+ _T5 = 0xF8 // 1111 1000
+
+ _Maskx = 0x3F // 0011 1111
+ _Mask2 = 0x1F // 0001 1111
+ _Mask3 = 0x0F // 0000 1111
+ _Mask4 = 0x07 // 0000 0111
+
+ _Rune1Max = 1<<7 - 1
+ _Rune2Max = 1<<11 - 1
+ _Rune3Max = 1<<16 - 1
+ _Rune4Max = 1<<21 - 1
)
func decodeRuneInternal(p []byte) (rune, size int, short bool) {
- n := len(p);
+ n := len(p)
if n < 1 {
return RuneError, 0, true
}
- c0 := p[0];
+ c0 := p[0]
// 1-byte, 7-bit sequence?
if c0 < _Tx {
@@ -55,66 +55,66 @@ func decodeRuneInternal(p []byte) (rune, size int, short bool) {
if n < 2 {
return RuneError, 1, true
}
- c1 := p[1];
+ c1 := p[1]
if c1 < _Tx || _T2 <= c1 {
return RuneError, 1, false
}
// 2-byte, 11-bit sequence?
if c0 < _T3 {
- rune = int(c0&_Mask2)<<6 | int(c1&_Maskx);
+ rune = int(c0&_Mask2)<<6 | int(c1&_Maskx)
if rune <= _Rune1Max {
return RuneError, 1, false
}
- return rune, 2, false;
+ return rune, 2, false
}
// need second continuation byte
if n < 3 {
return RuneError, 1, true
}
- c2 := p[2];
+ c2 := p[2]
if c2 < _Tx || _T2 <= c2 {
return RuneError, 1, false
}
// 3-byte, 16-bit sequence?
if c0 < _T4 {
- rune = int(c0&_Mask3)<<12 | int(c1&_Maskx)<<6 | int(c2&_Maskx);
+ rune = int(c0&_Mask3)<<12 | int(c1&_Maskx)<<6 | int(c2&_Maskx)
if rune <= _Rune2Max {
return RuneError, 1, false
}
- return rune, 3, false;
+ return rune, 3, false
}
// need third continuation byte
if n < 4 {
return RuneError, 1, true
}
- c3 := p[3];
+ c3 := p[3]
if c3 < _Tx || _T2 <= c3 {
return RuneError, 1, false
}
// 4-byte, 21-bit sequence?
if c0 < _T5 {
- rune = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx);
+ rune = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx)
if rune <= _Rune3Max {
return RuneError, 1, false
}
- return rune, 4, false;
+ return rune, 4, false
}
// error
- return RuneError, 1, false;
+ return RuneError, 1, false
}
func decodeRuneInStringInternal(s string) (rune, size int, short bool) {
- n := len(s);
+ n := len(s)
if n < 1 {
return RuneError, 0, true
}
- c0 := s[0];
+ c0 := s[0]
// 1-byte, 7-bit sequence?
if c0 < _Tx {
@@ -130,83 +130,83 @@ func decodeRuneInStringInternal(s string) (rune, size int, short bool) {
if n < 2 {
return RuneError, 1, true
}
- c1 := s[1];
+ c1 := s[1]
if c1 < _Tx || _T2 <= c1 {
return RuneError, 1, false
}
// 2-byte, 11-bit sequence?
if c0 < _T3 {
- rune = int(c0&_Mask2)<<6 | int(c1&_Maskx);
+ rune = int(c0&_Mask2)<<6 | int(c1&_Maskx)
if rune <= _Rune1Max {
return RuneError, 1, false
}
- return rune, 2, false;
+ return rune, 2, false
}
// need second continuation byte
if n < 3 {
return RuneError, 1, true
}
- c2 := s[2];
+ c2 := s[2]
if c2 < _Tx || _T2 <= c2 {
return RuneError, 1, false
}
// 3-byte, 16-bit sequence?
if c0 < _T4 {
- rune = int(c0&_Mask3)<<12 | int(c1&_Maskx)<<6 | int(c2&_Maskx);
+ rune = int(c0&_Mask3)<<12 | int(c1&_Maskx)<<6 | int(c2&_Maskx)
if rune <= _Rune2Max {
return RuneError, 1, false
}
- return rune, 3, false;
+ return rune, 3, false
}
// need third continuation byte
if n < 4 {
return RuneError, 1, true
}
- c3 := s[3];
+ c3 := s[3]
if c3 < _Tx || _T2 <= c3 {
return RuneError, 1, false
}
// 4-byte, 21-bit sequence?
if c0 < _T5 {
- rune = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx);
+ rune = int(c0&_Mask4)<<18 | int(c1&_Maskx)<<12 | int(c2&_Maskx)<<6 | int(c3&_Maskx)
if rune <= _Rune3Max {
return RuneError, 1, false
}
- return rune, 4, false;
+ return rune, 4, false
}
// error
- return RuneError, 1, false;
+ return RuneError, 1, false
}
// 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 FullRune(p []byte) bool {
- _, _, short := decodeRuneInternal(p);
- return !short;
+ _, _, short := decodeRuneInternal(p)
+ return !short
}
// FullRuneInString is like FullRune but its input is a string.
func FullRuneInString(s string) bool {
- _, _, short := decodeRuneInStringInternal(s);
- return !short;
+ _, _, short := decodeRuneInStringInternal(s)
+ return !short
}
// DecodeRune unpacks the first UTF-8 encoding in p and returns the rune and its width in bytes.
func DecodeRune(p []byte) (rune, size int) {
- rune, size, _ = decodeRuneInternal(p);
- return;
+ rune, size, _ = decodeRuneInternal(p)
+ return
}
// DecodeRuneInString is like DecodeRune but its input is a string.
func DecodeRuneInString(s string) (rune, size int) {
- rune, size, _ = decodeRuneInStringInternal(s);
- return;
+ rune, size, _ = decodeRuneInStringInternal(s)
+ return
}
// RuneLen returns the number of bytes required to encode the rune.
@@ -221,24 +221,24 @@ func RuneLen(rune int) int {
case rune <= _Rune4Max:
return 4
}
- return -1;
+ return -1
}
// EncodeRune writes into p (which must be large enough) the UTF-8 encoding of the rune.
// It returns the number of bytes written.
func EncodeRune(rune int, p []byte) int {
// Negative values are erroneous. Making it unsigned addresses the problem.
- r := uint(rune);
+ r := uint(rune)
if r <= _Rune1Max {
- p[0] = byte(r);
- return 1;
+ p[0] = byte(r)
+ return 1
}
if r <= _Rune2Max {
- p[0] = _T2 | byte(r>>6);
- p[1] = _Tx | byte(r)&_Maskx;
- return 2;
+ p[0] = _T2 | byte(r>>6)
+ p[1] = _Tx | byte(r)&_Maskx
+ return 2
}
if r > unicode.MaxRune {
@@ -246,33 +246,33 @@ func EncodeRune(rune int, p []byte) int {
}
if r <= _Rune3Max {
- p[0] = _T3 | byte(r>>12);
- p[1] = _Tx | byte(r>>6)&_Maskx;
- p[2] = _Tx | byte(r)&_Maskx;
- return 3;
+ p[0] = _T3 | byte(r>>12)
+ p[1] = _Tx | byte(r>>6)&_Maskx
+ p[2] = _Tx | byte(r)&_Maskx
+ return 3
}
- p[0] = _T4 | byte(r>>18);
- p[1] = _Tx | byte(r>>12)&_Maskx;
- p[2] = _Tx | byte(r>>6)&_Maskx;
- p[3] = _Tx | byte(r)&_Maskx;
- return 4;
+ p[0] = _T4 | byte(r>>18)
+ p[1] = _Tx | byte(r>>12)&_Maskx
+ p[2] = _Tx | byte(r>>6)&_Maskx
+ p[3] = _Tx | byte(r)&_Maskx
+ return 4
}
// RuneCount returns the number of runes in p. Erroneous and short
// encodings are treated as single runes of width 1 byte.
func RuneCount(p []byte) int {
- i := 0;
- var n int;
+ i := 0
+ var n int
for n = 0; i < len(p); n++ {
if p[i] < RuneSelf {
i++
} else {
- _, size := DecodeRune(p[i:]);
- i += size;
+ _, size := DecodeRune(p[i:])
+ i += size
}
}
- return n;
+ return n
}
// RuneCountInString is like RuneCount but its input is a string.
@@ -280,10 +280,10 @@ func RuneCountInString(s string) (n int) {
for _ = range s {
n++
}
- return;
+ return
}
// 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 RuneStart(b byte) bool { return b&0xC0 != 0x80 }
+func RuneStart(b byte) bool { return b&0xC0 != 0x80 }
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-25 17:40:34 +0000