unicode, utf8, utf16: use rune
Everything changes.
R=r
CC=golang-dev
https://golang.org/cl/5310045
diff --git a/src/pkg/utf8/utf8.go b/src/pkg/utf8/utf8.go
index 3cd919d..a5f9983 100644
--- a/src/pkg/utf8/utf8.go
+++ b/src/pkg/utf8/utf8.go
@@ -34,7 +34,7 @@
rune4Max = 1<<21 - 1
)
-func decodeRuneInternal(p []byte) (rune, size int, short bool) {
+func decodeRuneInternal(p []byte) (r rune, size int, short bool) {
n := len(p)
if n < 1 {
return RuneError, 0, true
@@ -43,7 +43,7 @@
// 1-byte, 7-bit sequence?
if c0 < tx {
- return int(c0), 1, false
+ return rune(c0), 1, false
}
// unexpected continuation byte?
@@ -62,11 +62,11 @@
// 2-byte, 11-bit sequence?
if c0 < t3 {
- rune = int(c0&mask2)<<6 | int(c1&maskx)
- if rune <= rune1Max {
+ r = rune(c0&mask2)<<6 | rune(c1&maskx)
+ if r <= rune1Max {
return RuneError, 1, false
}
- return rune, 2, false
+ return r, 2, false
}
// need second continuation byte
@@ -80,11 +80,11 @@
// 3-byte, 16-bit sequence?
if c0 < t4 {
- rune = int(c0&mask3)<<12 | int(c1&maskx)<<6 | int(c2&maskx)
- if rune <= rune2Max {
+ r = rune(c0&mask3)<<12 | rune(c1&maskx)<<6 | rune(c2&maskx)
+ if r <= rune2Max {
return RuneError, 1, false
}
- return rune, 3, false
+ return r, 3, false
}
// need third continuation byte
@@ -98,18 +98,18 @@
// 4-byte, 21-bit sequence?
if c0 < t5 {
- rune = int(c0&mask4)<<18 | int(c1&maskx)<<12 | int(c2&maskx)<<6 | int(c3&maskx)
- if rune <= rune3Max {
+ r = rune(c0&mask4)<<18 | rune(c1&maskx)<<12 | rune(c2&maskx)<<6 | rune(c3&maskx)
+ if r <= rune3Max {
return RuneError, 1, false
}
- return rune, 4, false
+ return r, 4, false
}
// error
return RuneError, 1, false
}
-func decodeRuneInStringInternal(s string) (rune, size int, short bool) {
+func decodeRuneInStringInternal(s string) (r rune, size int, short bool) {
n := len(s)
if n < 1 {
return RuneError, 0, true
@@ -118,7 +118,7 @@
// 1-byte, 7-bit sequence?
if c0 < tx {
- return int(c0), 1, false
+ return rune(c0), 1, false
}
// unexpected continuation byte?
@@ -137,11 +137,11 @@
// 2-byte, 11-bit sequence?
if c0 < t3 {
- rune = int(c0&mask2)<<6 | int(c1&maskx)
- if rune <= rune1Max {
+ r = rune(c0&mask2)<<6 | rune(c1&maskx)
+ if r <= rune1Max {
return RuneError, 1, false
}
- return rune, 2, false
+ return r, 2, false
}
// need second continuation byte
@@ -155,11 +155,11 @@
// 3-byte, 16-bit sequence?
if c0 < t4 {
- rune = int(c0&mask3)<<12 | int(c1&maskx)<<6 | int(c2&maskx)
- if rune <= rune2Max {
+ r = rune(c0&mask3)<<12 | rune(c1&maskx)<<6 | rune(c2&maskx)
+ if r <= rune2Max {
return RuneError, 1, false
}
- return rune, 3, false
+ return r, 3, false
}
// need third continuation byte
@@ -173,11 +173,11 @@
// 4-byte, 21-bit sequence?
if c0 < t5 {
- rune = int(c0&mask4)<<18 | int(c1&maskx)<<12 | int(c2&maskx)<<6 | int(c3&maskx)
- if rune <= rune3Max {
+ r = rune(c0&mask4)<<18 | rune(c1&maskx)<<12 | rune(c2&maskx)<<6 | rune(c3&maskx)
+ if r <= rune3Max {
return RuneError, 1, false
}
- return rune, 4, false
+ return r, 4, false
}
// error
@@ -198,28 +198,28 @@
}
// 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)
+func DecodeRune(p []byte) (r rune, size int) {
+ r, 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)
+func DecodeRuneInString(s string) (r rune, size int) {
+ r, size, _ = decodeRuneInStringInternal(s)
return
}
// DecodeLastRune unpacks the last UTF-8 encoding in p
// and returns the rune and its width in bytes.
-func DecodeLastRune(p []byte) (rune, size int) {
+func DecodeLastRune(p []byte) (r rune, size int) {
end := len(p)
if end == 0 {
return RuneError, 0
}
start := end - 1
- rune = int(p[start])
- if rune < RuneSelf {
- return rune, 1
+ r = rune(p[start])
+ if r < RuneSelf {
+ return r, 1
}
// guard against O(n^2) behavior when traversing
// backwards through strings with long sequences of
@@ -236,23 +236,23 @@
if start < 0 {
start = 0
}
- rune, size = DecodeRune(p[start:end])
+ r, size = DecodeRune(p[start:end])
if start+size != end {
return RuneError, 1
}
- return rune, size
+ return r, size
}
// DecodeLastRuneInString is like DecodeLastRune but its input is a string.
-func DecodeLastRuneInString(s string) (rune, size int) {
+func DecodeLastRuneInString(s string) (r rune, size int) {
end := len(s)
if end == 0 {
return RuneError, 0
}
start := end - 1
- rune = int(s[start])
- if rune < RuneSelf {
- return rune, 1
+ r = rune(s[start])
+ if r < RuneSelf {
+ return r, 1
}
// guard against O(n^2) behavior when traversing
// backwards through strings with long sequences of
@@ -269,23 +269,23 @@
if start < 0 {
start = 0
}
- rune, size = DecodeRuneInString(s[start:end])
+ r, size = DecodeRuneInString(s[start:end])
if start+size != end {
return RuneError, 1
}
- return rune, size
+ return r, size
}
// RuneLen returns the number of bytes required to encode the rune.
-func RuneLen(rune int) int {
+func RuneLen(r rune) int {
switch {
- case rune <= rune1Max:
+ case r <= rune1Max:
return 1
- case rune <= rune2Max:
+ case r <= rune2Max:
return 2
- case rune <= rune3Max:
+ case r <= rune3Max:
return 3
- case rune <= rune4Max:
+ case r <= rune4Max:
return 4
}
return -1
@@ -293,26 +293,24 @@
// 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(p []byte, rune int) int {
+func EncodeRune(p []byte, r rune) int {
// Negative values are erroneous. Making it unsigned addresses the problem.
- r := uint(rune)
-
- if r <= rune1Max {
+ if uint32(r) <= rune1Max {
p[0] = byte(r)
return 1
}
- if r <= rune2Max {
+ if uint32(r) <= rune2Max {
p[0] = t2 | byte(r>>6)
p[1] = tx | byte(r)&maskx
return 2
}
- if r > unicode.MaxRune {
+ if uint32(r) > unicode.MaxRune {
r = RuneError
}
- if r <= rune3Max {
+ if uint32(r) <= rune3Max {
p[0] = t3 | byte(r>>12)
p[1] = tx | byte(r>>6)&maskx
p[2] = tx | byte(r)&maskx
