diff options
Diffstat (limited to 'src/strings/strings.go')
| -rw-r--r-- | src/strings/strings.go | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/src/strings/strings.go b/src/strings/strings.go index 64022533ea..349989278d 100644 --- a/src/strings/strings.go +++ b/src/strings/strings.go @@ -145,12 +145,24 @@ func LastIndex(s, sep string) int { // IndexRune returns the index of the first instance of the Unicode code point // r, or -1 if rune is not present in s. +// If r is utf8.RuneError, it returns the first instance of any +// invalid UTF-8 byte sequence. func IndexRune(s string, r rune) int { - if r < utf8.RuneSelf { + switch { + case 0 <= r && r < utf8.RuneSelf: return IndexByte(s, byte(r)) + case r == utf8.RuneError: + for i, r := range s { + if r == utf8.RuneError { + return i + } + } + return -1 + case !utf8.ValidRune(r): + return -1 + default: + return Index(s, string(r)) } - - return Index(s, string(r)) } // IndexAny returns the index of the first instance of any Unicode code point |