Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

bytes, strings: allow -1 in Map to mean "drop this character".

Browse source 
xml: drop invalid characters in attribute names
    when constructing struct field names.

R=rsc
CC=r
https://golang.org/cl/157104
This commit is contained in:
Kei Son 2009-12-11 10:37:48 -08:00 • committed by Russ Cox
parent 67aa1399d6
commit 128974adfd
6 changed files with 91 additions and 26 deletions
Download patch file Download diff file Expand all files Collapse all files

29
src/pkg/strings/strings.go
View file

@ -178,7 +178,8 @@ func HasSuffix(s, suffix string) bool {
}
// Map returns a copy of the string s with all its characters modified
// according to the mapping function.
// according to the mapping function. If mapping returns a negative value, the character is
// dropped from the string with no replacement.
func Map(mapping func(rune int) int, s string) string {
// In the worst case, the string can grow when mapped, making
// things unpleasant. But it's so rare we barge in assuming it's
@ -188,20 +189,22 @@ func Map(mapping func(rune int) int, s string) string {
b := make([]byte, maxbytes);
for _, c := range s {
rune := mapping(c);
wid := 1;
if rune >= utf8.RuneSelf {
wid = utf8.RuneLen(rune)
}
if nbytes+wid > maxbytes {
// Grow the buffer.
maxbytes = maxbytes*2 + utf8.UTFMax;
nb := make([]byte, maxbytes);
for i, c := range b[0:nbytes] {
nb[i] = c
if rune >= 0 {
wid := 1;
if rune >= utf8.RuneSelf {
wid = utf8.RuneLen(rune)
}
b = nb;
if nbytes+wid > maxbytes {
// Grow the buffer.
maxbytes = maxbytes*2 + utf8.UTFMax;
nb := make([]byte, maxbytes);
for i, c := range b[0:nbytes] {
nb[i] = c
}
b = nb;
}
nbytes += utf8.EncodeRune(rune, b[nbytes:maxbytes]);
}
nbytes += utf8.EncodeRune(rune, b[nbytes:maxbytes]);
}
return string(b[0:nbytes]);
}