Retro68/gcc/libgo/go/bytes/bytes_generic.go
2017-10-07 02:16:47 +02:00

42 lines
760 B
Go

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// -build !amd64,!s390x
package bytes
// TODO: implements short string optimization on non amd64 platforms
// and get rid of bytes_amd64.go
// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
func Index(s, sep []byte) int {
n := len(sep)
if n == 0 {
return 0
}
if n > len(s) {
return -1
}
c := sep[0]
if n == 1 {
return IndexByte(s, c)
}
i := 0
t := s[:len(s)-n+1]
for i < len(t) {
if t[i] != c {
o := IndexByte(t[i:], c)
if o < 0 {
break
}
i += o
}
if Equal(s[i:i+n], sep) {
return i
}
i++
}
return -1
}