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// Copyright 2009 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.
 
// Package bytes implements functions for the manipulation of byte slices.
// It is analogous to the facilities of the strings package.
package bytes
 
import (
        "unicode"
        "unicode/utf8"
)
 
// Compare returns an integer comparing the two byte arrays lexicographically.
// The result will be 0 if a==b, -1 if a < b, and +1 if a > b
func Compare(a, b []byte) int {
        m := len(a)
        if m > len(b) {
                m = len(b)
        }
        for i, ac := range a[0:m] {
                bc := b[i]
                switch {
                case ac > bc:
                        return 1
                case ac < bc:
                        return -1
                }
        }
        switch {
        case len(a) < len(b):
                return -1
        case len(a) > len(b):
                return 1
        }
        return 0
}
 
// Equal returns a boolean reporting whether a == b.
func Equal(a, b []byte) bool
 
func equalPortable(a, b []byte) bool {
        if len(a) != len(b) {
                return false
        }
        for i, c := range a {
                if c != b[i] {
                        return false
                }
        }
        return true
}
 
// explode splits s into an array of UTF-8 sequences, one per Unicode character (still arrays of bytes),
// up to a maximum of n byte arrays. Invalid UTF-8 sequences are chopped into individual bytes.
func explode(s []byte, n int) [][]byte {
        if n <= 0 {
                n = len(s)
        }
        a := make([][]byte, n)
        var size int
        na := 0
        for len(s) > 0 {
                if na+1 >= n {
                        a[na] = s
                        na++
                        break
                }
                _, size = utf8.DecodeRune(s)
                a[na] = s[0:size]
                s = s[size:]
                na++
        }
        return a[0:na]
}
 
// Count counts the number of non-overlapping instances of sep in s.
func Count(s, sep []byte) int {
        n := len(sep)
        if n == 0 {
                return utf8.RuneCount(s) + 1
        }
        if n > len(s) {
                return 0
        }
        count := 0
        c := sep[0]
        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 n == 1 || Equal(s[i:i+n], sep) {
                        count++
                        i += n
                        continue
                }
                i++
        }
        return count
}
 
// Contains returns whether subslice is within b.
func Contains(b, subslice []byte) bool {
        return Index(b, subslice) != -1
}
 
// 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
}
 
func indexBytePortable(s []byte, c byte) int {
        for i, b := range s {
                if b == c {
                        return i
                }
        }
        return -1
}
 
// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
func LastIndex(s, sep []byte) int {
        n := len(sep)
        if n == 0 {
                return len(s)
        }
        c := sep[0]
        for i := len(s) - n; i >= 0; i-- {
                if s[i] == c && (n == 1 || Equal(s[i:i+n], sep)) {
                        return i
                }
        }
        return -1
}
 
// IndexRune interprets s as a sequence of UTF-8-encoded Unicode code points.
// It returns the byte index of the first occurrence in s of the given rune.
// It returns -1 if rune is not present in s.
func IndexRune(s []byte, r rune) int {
        for i := 0; i < len(s); {
                r1, size := utf8.DecodeRune(s[i:])
                if r == r1 {
                        return i
                }
                i += size
        }
        return -1
}
 
// IndexAny interprets s as a sequence of UTF-8-encoded Unicode code points.
// It returns the byte index of the first occurrence in s of any of the Unicode
// code points in chars.  It returns -1 if chars is empty or if there is no code
// point in common.
func IndexAny(s []byte, chars string) int {
        if len(chars) > 0 {
                var r rune
                var width int
                for i := 0; i < len(s); i += width {
                        r = rune(s[i])
                        if r < utf8.RuneSelf {
                                width = 1
                        } else {
                                r, width = utf8.DecodeRune(s[i:])
                        }
                        for _, ch := range chars {
                                if r == ch {
                                        return i
                                }
                        }
                }
        }
        return -1
}
 
// LastIndexAny interprets s as a sequence of UTF-8-encoded Unicode code
// points.  It returns the byte index of the last occurrence in s of any of
// the Unicode code points in chars.  It returns -1 if chars is empty or if
// there is no code point in common.
func LastIndexAny(s []byte, chars string) int {
        if len(chars) > 0 {
                for i := len(s); i > 0; {
                        r, size := utf8.DecodeLastRune(s[0:i])
                        i -= size
                        for _, ch := range chars {
                                if r == ch {
                                        return i
                                }
                        }
                }
        }
        return -1
}
 
// Generic split: splits after each instance of sep,
// including sepSave bytes of sep in the subarrays.
func genSplit(s, sep []byte, sepSave, n int) [][]byte {
        if n == 0 {
                return nil
        }
        if len(sep) == 0 {
                return explode(s, n)
        }
        if n < 0 {
                n = Count(s, sep) + 1
        }
        c := sep[0]
        start := 0
        a := make([][]byte, n)
        na := 0
        for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ {
                if s[i] == c && (len(sep) == 1 || Equal(s[i:i+len(sep)], sep)) {
                        a[na] = s[start : i+sepSave]
                        na++
                        start = i + len(sep)
                        i += len(sep) - 1
                }
        }
        a[na] = s[start:]
        return a[0 : na+1]
}
 
// SplitN slices s into subslices separated by sep and returns a slice of
// the subslices between those separators.
// If sep is empty, SplitN splits after each UTF-8 sequence.
// The count determines the number of subslices to return:
//   n > 0: at most n subslices; the last subslice will be the unsplit remainder.
//   n == 0: the result is nil (zero subslices)
//   n < 0: all subslices
func SplitN(s, sep []byte, n int) [][]byte { return genSplit(s, sep, 0, n) }
 
// SplitAfterN slices s into subslices after each instance of sep and
// returns a slice of those subslices.
// If sep is empty, SplitAfterN splits after each UTF-8 sequence.
// The count determines the number of subslices to return:
//   n > 0: at most n subslices; the last subslice will be the unsplit remainder.
//   n == 0: the result is nil (zero subslices)
//   n < 0: all subslices
func SplitAfterN(s, sep []byte, n int) [][]byte {
        return genSplit(s, sep, len(sep), n)
}
 
// Split slices s into all subslices separated by sep and returns a slice of
// the subslices between those separators.
// If sep is empty, Split splits after each UTF-8 sequence.
// It is equivalent to SplitN with a count of -1.
func Split(s, sep []byte) [][]byte { return genSplit(s, sep, 0, -1) }
 
// SplitAfter slices s into all subslices after each instance of sep and
// returns a slice of those subslices.
// If sep is empty, SplitAfter splits after each UTF-8 sequence.
// It is equivalent to SplitAfterN with a count of -1.
func SplitAfter(s, sep []byte) [][]byte {
        return genSplit(s, sep, len(sep), -1)
}
 
// Fields splits the array s around each instance of one or more consecutive white space
// characters, returning a slice of subarrays of s or an empty list if s contains only white space.
func Fields(s []byte) [][]byte {
        return FieldsFunc(s, unicode.IsSpace)
}
 
// FieldsFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
// It splits the array s at each run of code points c satisfying f(c) and
// returns a slice of subarrays of s.  If no code points in s satisfy f(c), an
// empty slice is returned.
func FieldsFunc(s []byte, f func(rune) bool) [][]byte {
        n := 0
        inField := false
        for i := 0; i < len(s); {
                r, size := utf8.DecodeRune(s[i:])
                wasInField := inField
                inField = !f(r)
                if inField && !wasInField {
                        n++
                }
                i += size
        }
 
        a := make([][]byte, n)
        na := 0
        fieldStart := -1
        for i := 0; i <= len(s) && na < n; {
                r, size := utf8.DecodeRune(s[i:])
                if fieldStart < 0 && size > 0 && !f(r) {
                        fieldStart = i
                        i += size
                        continue
                }
                if fieldStart >= 0 && (size == 0 || f(r)) {
                        a[na] = s[fieldStart:i]
                        na++
                        fieldStart = -1
                }
                if size == 0 {
                        break
                }
                i += size
        }
        return a[0:na]
}
 
// Join concatenates the elements of a to create a single byte array.   The separator
// sep is placed between elements in the resulting array.
func Join(a [][]byte, sep []byte) []byte {
        if len(a) == 0 {
                return []byte{}
        }
        if len(a) == 1 {
                return a[0]
        }
        n := len(sep) * (len(a) - 1)
        for i := 0; i < len(a); i++ {
                n += len(a[i])
        }
 
        b := make([]byte, n)
        bp := copy(b, a[0])
        for _, s := range a[1:] {
                bp += copy(b[bp:], sep)
                bp += copy(b[bp:], s)
        }
        return b
}
 
// HasPrefix tests whether the byte array s begins with prefix.
func HasPrefix(s, prefix []byte) bool {
        return len(s) >= len(prefix) && Equal(s[0:len(prefix)], prefix)
}
 
// HasSuffix tests whether the byte array s ends with suffix.
func HasSuffix(s, suffix []byte) bool {
        return len(s) >= len(suffix) && Equal(s[len(s)-len(suffix):], suffix)
}
 
// Map returns a copy of the byte array s with all its characters modified
// according to the mapping function. If mapping returns a negative value, the character is
// dropped from the string with no replacement.  The characters in s and the
// output are interpreted as UTF-8-encoded Unicode code points.
func Map(mapping func(r rune) rune, s []byte) []byte {
        // In the worst case, the array can grow when mapped, making
        // things unpleasant.  But it's so rare we barge in assuming it's
        // fine.  It could also shrink but that falls out naturally.
        maxbytes := len(s) // length of b
        nbytes := 0        // number of bytes encoded in b
        b := make([]byte, maxbytes)
        for i := 0; i < len(s); {
                wid := 1
                r := rune(s[i])
                if r >= utf8.RuneSelf {
                        r, wid = utf8.DecodeRune(s[i:])
                }
                r = mapping(r)
                if r >= 0 {
                        if nbytes+utf8.RuneLen(r) > maxbytes {
                                // Grow the buffer.
                                maxbytes = maxbytes*2 + utf8.UTFMax
                                nb := make([]byte, maxbytes)
                                copy(nb, b[0:nbytes])
                                b = nb
                        }
                        nbytes += utf8.EncodeRune(b[nbytes:maxbytes], r)
                }
                i += wid
        }
        return b[0:nbytes]
}
 
// Repeat returns a new byte slice consisting of count copies of b.
func Repeat(b []byte, count int) []byte {
        nb := make([]byte, len(b)*count)
        bp := 0
        for i := 0; i < count; i++ {
                for j := 0; j < len(b); j++ {
                        nb[bp] = b[j]
                        bp++
                }
        }
        return nb
}
 
// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their upper case.
func ToUpper(s []byte) []byte { return Map(unicode.ToUpper, s) }
 
// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their lower case.
func ToLower(s []byte) []byte { return Map(unicode.ToLower, s) }
 
// ToTitle returns a copy of the byte array s with all Unicode letters mapped to their title case.
func ToTitle(s []byte) []byte { return Map(unicode.ToTitle, s) }
 
// ToUpperSpecial returns a copy of the byte array s with all Unicode letters mapped to their
// upper case, giving priority to the special casing rules.
func ToUpperSpecial(_case unicode.SpecialCase, s []byte) []byte {
        return Map(func(r rune) rune { return _case.ToUpper(r) }, s)
}
 
// ToLowerSpecial returns a copy of the byte array s with all Unicode letters mapped to their
// lower case, giving priority to the special casing rules.
func ToLowerSpecial(_case unicode.SpecialCase, s []byte) []byte {
        return Map(func(r rune) rune { return _case.ToLower(r) }, s)
}
 
// ToTitleSpecial returns a copy of the byte array s with all Unicode letters mapped to their
// title case, giving priority to the special casing rules.
func ToTitleSpecial(_case unicode.SpecialCase, s []byte) []byte {
        return Map(func(r rune) rune { return _case.ToTitle(r) }, s)
}
 
// isSeparator reports whether the rune could mark a word boundary.
// TODO: update when package unicode captures more of the properties.
func isSeparator(r rune) bool {
        // ASCII alphanumerics and underscore are not separators
        if r <= 0x7F {
                switch {
                case '0' <= r && r <= '9':
                        return false
                case 'a' <= r && r <= 'z':
                        return false
                case 'A' <= r && r <= 'Z':
                        return false
                case r == '_':
                        return false
                }
                return true
        }
        // Letters and digits are not separators
        if unicode.IsLetter(r) || unicode.IsDigit(r) {
                return false
        }
        // Otherwise, all we can do for now is treat spaces as separators.
        return unicode.IsSpace(r)
}
 
// BUG(r): The rule Title uses for word boundaries does not handle Unicode punctuation properly.
 
// Title returns a copy of s with all Unicode letters that begin words
// mapped to their title case.
func Title(s []byte) []byte {
        // Use a closure here to remember state.
        // Hackish but effective. Depends on Map scanning in order and calling
        // the closure once per rune.
        prev := ' '
        return Map(
                func(r rune) rune {
                        if isSeparator(prev) {
                                prev = r
                                return unicode.ToTitle(r)
                        }
                        prev = r
                        return r
                },
                s)
}
 
// TrimLeftFunc returns a subslice of s by slicing off all leading UTF-8-encoded
// Unicode code points c that satisfy f(c).
func TrimLeftFunc(s []byte, f func(r rune) bool) []byte {
        i := indexFunc(s, f, false)
        if i == -1 {
                return nil
        }
        return s[i:]
}
 
// TrimRightFunc returns a subslice of s by slicing off all trailing UTF-8
// encoded Unicode code points c that satisfy f(c).
func TrimRightFunc(s []byte, f func(r rune) bool) []byte {
        i := lastIndexFunc(s, f, false)
        if i >= 0 && s[i] >= utf8.RuneSelf {
                _, wid := utf8.DecodeRune(s[i:])
                i += wid
        } else {
                i++
        }
        return s[0:i]
}
 
// TrimFunc returns a subslice of s by slicing off all leading and trailing
// UTF-8-encoded Unicode code points c that satisfy f(c).
func TrimFunc(s []byte, f func(r rune) bool) []byte {
        return TrimRightFunc(TrimLeftFunc(s, f), f)
}
 
// IndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
// It returns the byte index in s of the first Unicode
// code point satisfying f(c), or -1 if none do.
func IndexFunc(s []byte, f func(r rune) bool) int {
        return indexFunc(s, f, true)
}
 
// LastIndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
// It returns the byte index in s of the last Unicode
// code point satisfying f(c), or -1 if none do.
func LastIndexFunc(s []byte, f func(r rune) bool) int {
        return lastIndexFunc(s, f, true)
}
 
// indexFunc is the same as IndexFunc except that if
// truth==false, the sense of the predicate function is
// inverted.
func indexFunc(s []byte, f func(r rune) bool, truth bool) int {
        start := 0
        for start < len(s) {
                wid := 1
                r := rune(s[start])
                if r >= utf8.RuneSelf {
                        r, wid = utf8.DecodeRune(s[start:])
                }
                if f(r) == truth {
                        return start
                }
                start += wid
        }
        return -1
}
 
// lastIndexFunc is the same as LastIndexFunc except that if
// truth==false, the sense of the predicate function is
// inverted.
func lastIndexFunc(s []byte, f func(r rune) bool, truth bool) int {
        for i := len(s); i > 0; {
                r, size := utf8.DecodeLastRune(s[0:i])
                i -= size
                if f(r) == truth {
                        return i
                }
        }
        return -1
}
 
func makeCutsetFunc(cutset string) func(r rune) bool {
        return func(r rune) bool {
                for _, c := range cutset {
                        if c == r {
                                return true
                        }
                }
                return false
        }
}
 
// Trim returns a subslice of s by slicing off all leading and
// trailing UTF-8-encoded Unicode code points contained in cutset.
func Trim(s []byte, cutset string) []byte {
        return TrimFunc(s, makeCutsetFunc(cutset))
}
 
// TrimLeft returns a subslice of s by slicing off all leading
// UTF-8-encoded Unicode code points contained in cutset.
func TrimLeft(s []byte, cutset string) []byte {
        return TrimLeftFunc(s, makeCutsetFunc(cutset))
}
 
// TrimRight returns a subslice of s by slicing off all trailing
// UTF-8-encoded Unicode code points that are contained in cutset.
func TrimRight(s []byte, cutset string) []byte {
        return TrimRightFunc(s, makeCutsetFunc(cutset))
}
 
// TrimSpace returns a subslice of s by slicing off all leading and
// trailing white space, as defined by Unicode.
func TrimSpace(s []byte) []byte {
        return TrimFunc(s, unicode.IsSpace)
}
 
// Runes returns a slice of runes (Unicode code points) equivalent to s.
func Runes(s []byte) []rune {
        t := make([]rune, utf8.RuneCount(s))
        i := 0
        for len(s) > 0 {
                r, l := utf8.DecodeRune(s)
                t[i] = r
                i++
                s = s[l:]
        }
        return t
}
 
// Replace returns a copy of the slice s with the first n
// non-overlapping instances of old replaced by new.
// If n < 0, there is no limit on the number of replacements.
func Replace(s, old, new []byte, n int) []byte {
        m := 0
        if n != 0 {
                // Compute number of replacements.
                m = Count(s, old)
        }
        if m == 0 {
                // Nothing to do. Just copy.
                t := make([]byte, len(s))
                copy(t, s)
                return t
        }
        if n < 0 || m < n {
                n = m
        }
 
        // Apply replacements to buffer.
        t := make([]byte, len(s)+n*(len(new)-len(old)))
        w := 0
        start := 0
        for i := 0; i < n; i++ {
                j := start
                if len(old) == 0 {
                        if i > 0 {
                                _, wid := utf8.DecodeRune(s[start:])
                                j += wid
                        }
                } else {
                        j += Index(s[start:], old)
                }
                w += copy(t[w:], s[start:j])
                w += copy(t[w:], new)
                start = j + len(old)
        }
        w += copy(t[w:], s[start:])
        return t[0:w]
}
 
// EqualFold reports whether s and t, interpreted as UTF-8 strings,
// are equal under Unicode case-folding.
func EqualFold(s, t []byte) bool {
        for len(s) != 0 && len(t) != 0 {
                // Extract first rune from each.
                var sr, tr rune
                if s[0] < utf8.RuneSelf {
                        sr, s = rune(s[0]), s[1:]
                } else {
                        r, size := utf8.DecodeRune(s)
                        sr, s = r, s[size:]
                }
                if t[0] < utf8.RuneSelf {
                        tr, t = rune(t[0]), t[1:]
                } else {
                        r, size := utf8.DecodeRune(t)
                        tr, t = r, t[size:]
                }
 
                // If they match, keep going; if not, return false.
 
                // Easy case.
                if tr == sr {
                        continue
                }
 
                // Make sr < tr to simplify what follows.
                if tr < sr {
                        tr, sr = sr, tr
                }
                // Fast check for ASCII.
                if tr < utf8.RuneSelf && 'A' <= sr && sr <= 'Z' {
                        // ASCII, and sr is upper case.  tr must be lower case.
                        if tr == sr+'a'-'A' {
                                continue
                        }
                        return false
                }
 
                // General case.  SimpleFold(x) returns the next equivalent rune > x
                // or wraps around to smaller values.
                r := unicode.SimpleFold(sr)
                for r != sr && r < tr {
                        r = unicode.SimpleFold(r)
                }
                if r == tr {
                        continue
                }
                return false
        }
 
        // One string is empty.  Are both?
        return len(s) == len(t)
}

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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgo/] [go/] [bytes/] [bytes.go] - Blame information for rev 774

Line No.	Rev	Author	Line
1	747	jeremybenn	`// Copyright 2009 The Go Authors. All rights reserved.`
2			`// Use of this source code is governed by a BSD-style`
3			`// license that can be found in the LICENSE file.`
4
5			`// Package bytes implements functions for the manipulation of byte slices.`
6			`// It is analogous to the facilities of the strings package.`
7			`package bytes`
8
9			`import (`
10			`"unicode"`
11			`"unicode/utf8"`
12			`)`
13
14			`// Compare returns an integer comparing the two byte arrays lexicographically.`
15			`// The result will be 0 if a==b, -1 if a < b, and +1 if a > b`
16			`func Compare(a, b []byte) int {`
17			`m := len(a)`
18			`if m > len(b) {`
19			`m = len(b)`
20			`}`
21			`for i, ac := range a[0:m] {`
22			`bc := b[i]`
23			`switch {`
24			`case ac > bc:`
25			`return 1`
26			`case ac < bc:`
27			`return -1`
28			`}`
29			`}`
30			`switch {`
31			`case len(a) < len(b):`
32			`return -1`
33			`case len(a) > len(b):`
34			`return 1`
35			`}`
36			`return 0`
37			`}`
38
39			`// Equal returns a boolean reporting whether a == b.`
40			`func Equal(a, b []byte) bool`
41
42			`func equalPortable(a, b []byte) bool {`
43			`if len(a) != len(b) {`
44			`return false`
45			`}`
46			`for i, c := range a {`
47			`if c != b[i] {`
48			`return false`
49			`}`
50			`}`
51			`return true`
52			`}`
53
54			`// explode splits s into an array of UTF-8 sequences, one per Unicode character (still arrays of bytes),`
55			`// up to a maximum of n byte arrays. Invalid UTF-8 sequences are chopped into individual bytes.`
56			`func explode(s []byte, n int) [][]byte {`
57			`if n <= 0 {`
58			`n = len(s)`
59			`}`
60			`a := make([][]byte, n)`
61			`var size int`
62			`na := 0`
63			`for len(s) > 0 {`
64			`if na+1 >= n {`
65			`a[na] = s`
66			`na++`
67			`break`
68			`}`
69			`_, size = utf8.DecodeRune(s)`
70			`a[na] = s[0:size]`
71			`s = s[size:]`
72			`na++`
73			`}`
74			`return a[0:na]`
75			`}`
76
77			`// Count counts the number of non-overlapping instances of sep in s.`
78			`func Count(s, sep []byte) int {`
79			`n := len(sep)`
80			`if n == 0 {`
81			`return utf8.RuneCount(s) + 1`
82			`}`
83			`if n > len(s) {`
84			`return 0`
85			`}`
86			`count := 0`
87			`c := sep[0]`
88			`i := 0`
89			`t := s[:len(s)-n+1]`
90			`for i < len(t) {`
91			`if t[i] != c {`
92			`o := IndexByte(t[i:], c)`
93			`if o < 0 {`
94			`break`
95			`}`
96			`i += o`
97			`}`
98			`if n == 1 \|\| Equal(s[i:i+n], sep) {`
99			`count++`
100			`i += n`
101			`continue`
102			`}`
103			`i++`
104			`}`
105			`return count`
106			`}`
107
108			`// Contains returns whether subslice is within b.`
109			`func Contains(b, subslice []byte) bool {`
110			`return Index(b, subslice) != -1`
111			`}`
112
113			`// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.`
114			`func Index(s, sep []byte) int {`
115			`n := len(sep)`
116			`if n == 0 {`
117			`return 0`
118			`}`
119			`if n > len(s) {`
120			`return -1`
121			`}`
122			`c := sep[0]`
123			`if n == 1 {`
124			`return IndexByte(s, c)`
125			`}`
126			`i := 0`
127			`t := s[:len(s)-n+1]`
128			`for i < len(t) {`
129			`if t[i] != c {`
130			`o := IndexByte(t[i:], c)`
131			`if o < 0 {`
132			`break`
133			`}`
134			`i += o`
135			`}`
136			`if Equal(s[i:i+n], sep) {`
137			`return i`
138			`}`
139			`i++`
140			`}`
141			`return -1`
142			`}`
143
144			`func indexBytePortable(s []byte, c byte) int {`
145			`for i, b := range s {`
146			`if b == c {`
147			`return i`
148			`}`
149			`}`
150			`return -1`
151			`}`
152
153			`// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.`
154			`func LastIndex(s, sep []byte) int {`
155			`n := len(sep)`
156			`if n == 0 {`
157			`return len(s)`
158			`}`
159			`c := sep[0]`
160			`for i := len(s) - n; i >= 0; i-- {`
161			`if s[i] == c && (n == 1 \|\| Equal(s[i:i+n], sep)) {`
162			`return i`
163			`}`
164			`}`
165			`return -1`
166			`}`
167
168			`// IndexRune interprets s as a sequence of UTF-8-encoded Unicode code points.`
169			`// It returns the byte index of the first occurrence in s of the given rune.`
170			`// It returns -1 if rune is not present in s.`
171			`func IndexRune(s []byte, r rune) int {`
172			`for i := 0; i < len(s); {`
173			`r1, size := utf8.DecodeRune(s[i:])`
174			`if r == r1 {`
175			`return i`
176			`}`
177			`i += size`
178			`}`
179			`return -1`
180			`}`
181
182			`// IndexAny interprets s as a sequence of UTF-8-encoded Unicode code points.`
183			`// It returns the byte index of the first occurrence in s of any of the Unicode`
184			`// code points in chars. It returns -1 if chars is empty or if there is no code`
185			`// point in common.`
186			`func IndexAny(s []byte, chars string) int {`
187			`if len(chars) > 0 {`
188			`var r rune`
189			`var width int`
190			`for i := 0; i < len(s); i += width {`
191			`r = rune(s[i])`
192			`if r < utf8.RuneSelf {`
193			`width = 1`
194			`} else {`
195			`r, width = utf8.DecodeRune(s[i:])`
196			`}`
197			`for _, ch := range chars {`
198			`if r == ch {`
199			`return i`
200			`}`
201			`}`
202			`}`
203			`}`
204			`return -1`
205			`}`
206
207			`// LastIndexAny interprets s as a sequence of UTF-8-encoded Unicode code`
208			`// points. It returns the byte index of the last occurrence in s of any of`
209			`// the Unicode code points in chars. It returns -1 if chars is empty or if`
210			`// there is no code point in common.`
211			`func LastIndexAny(s []byte, chars string) int {`
212			`if len(chars) > 0 {`
213			`for i := len(s); i > 0; {`
214			`r, size := utf8.DecodeLastRune(s[0:i])`
215			`i -= size`
216			`for _, ch := range chars {`
217			`if r == ch {`
218			`return i`
219			`}`
220			`}`
221			`}`
222			`}`
223			`return -1`
224			`}`
225
226			`// Generic split: splits after each instance of sep,`
227			`// including sepSave bytes of sep in the subarrays.`
228			`func genSplit(s, sep []byte, sepSave, n int) [][]byte {`
229			`if n == 0 {`
230			`return nil`
231			`}`
232			`if len(sep) == 0 {`
233			`return explode(s, n)`
234			`}`
235			`if n < 0 {`
236			`n = Count(s, sep) + 1`
237			`}`
238			`c := sep[0]`
239			`start := 0`
240			`a := make([][]byte, n)`
241			`na := 0`
242			`for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ {`
243			`if s[i] == c && (len(sep) == 1 \|\| Equal(s[i:i+len(sep)], sep)) {`
244			`a[na] = s[start : i+sepSave]`
245			`na++`
246			`start = i + len(sep)`
247			`i += len(sep) - 1`
248			`}`
249			`}`
250			`a[na] = s[start:]`
251			`return a[0 : na+1]`
252			`}`
253
254			`// SplitN slices s into subslices separated by sep and returns a slice of`
255			`// the subslices between those separators.`
256			`// If sep is empty, SplitN splits after each UTF-8 sequence.`
257			`// The count determines the number of subslices to return:`
258			`// n > 0: at most n subslices; the last subslice will be the unsplit remainder.`
259			`// n == 0: the result is nil (zero subslices)`
260			`// n < 0: all subslices`
261			`func SplitN(s, sep []byte, n int) [][]byte { return genSplit(s, sep, 0, n) }`
262
263			`// SplitAfterN slices s into subslices after each instance of sep and`
264			`// returns a slice of those subslices.`
265			`// If sep is empty, SplitAfterN splits after each UTF-8 sequence.`
266			`// The count determines the number of subslices to return:`
267			`// n > 0: at most n subslices; the last subslice will be the unsplit remainder.`
268			`// n == 0: the result is nil (zero subslices)`
269			`// n < 0: all subslices`
270			`func SplitAfterN(s, sep []byte, n int) [][]byte {`
271			`return genSplit(s, sep, len(sep), n)`
272			`}`
273
274			`// Split slices s into all subslices separated by sep and returns a slice of`
275			`// the subslices between those separators.`
276			`// If sep is empty, Split splits after each UTF-8 sequence.`
277			`// It is equivalent to SplitN with a count of -1.`
278			`func Split(s, sep []byte) [][]byte { return genSplit(s, sep, 0, -1) }`
279
280			`// SplitAfter slices s into all subslices after each instance of sep and`
281			`// returns a slice of those subslices.`
282			`// If sep is empty, SplitAfter splits after each UTF-8 sequence.`
283			`// It is equivalent to SplitAfterN with a count of -1.`
284			`func SplitAfter(s, sep []byte) [][]byte {`
285			`return genSplit(s, sep, len(sep), -1)`
286			`}`
287
288			`// Fields splits the array s around each instance of one or more consecutive white space`
289			`// characters, returning a slice of subarrays of s or an empty list if s contains only white space.`
290			`func Fields(s []byte) [][]byte {`
291			`return FieldsFunc(s, unicode.IsSpace)`
292			`}`
293
294			`// FieldsFunc interprets s as a sequence of UTF-8-encoded Unicode code points.`
295			`// It splits the array s at each run of code points c satisfying f(c) and`
296			`// returns a slice of subarrays of s. If no code points in s satisfy f(c), an`
297			`// empty slice is returned.`
298			`func FieldsFunc(s []byte, f func(rune) bool) [][]byte {`
299			`n := 0`
300			`inField := false`
301			`for i := 0; i < len(s); {`
302			`r, size := utf8.DecodeRune(s[i:])`
303			`wasInField := inField`
304			`inField = !f(r)`
305			`if inField && !wasInField {`
306			`n++`
307			`}`
308			`i += size`
309			`}`
310
311			`a := make([][]byte, n)`
312			`na := 0`
313			`fieldStart := -1`
314			`for i := 0; i <= len(s) && na < n; {`
315			`r, size := utf8.DecodeRune(s[i:])`
316			`if fieldStart < 0 && size > 0 && !f(r) {`
317			`fieldStart = i`
318			`i += size`
319			`continue`
320			`}`
321			`if fieldStart >= 0 && (size == 0 \|\| f(r)) {`
322			`a[na] = s[fieldStart:i]`
323			`na++`
324			`fieldStart = -1`
325			`}`
326			`if size == 0 {`
327			`break`
328			`}`
329			`i += size`
330			`}`
331			`return a[0:na]`
332			`}`
333
334			`// Join concatenates the elements of a to create a single byte array. The separator`
335			`// sep is placed between elements in the resulting array.`
336			`func Join(a [][]byte, sep []byte) []byte {`
337			`if len(a) == 0 {`
338			`return []byte{}`
339			`}`
340			`if len(a) == 1 {`
341			`return a[0]`
342			`}`
343			`n := len(sep) * (len(a) - 1)`
344			`for i := 0; i < len(a); i++ {`
345			`n += len(a[i])`
346			`}`
347
348			`b := make([]byte, n)`
349			`bp := copy(b, a[0])`
350			`for _, s := range a[1:] {`
351			`bp += copy(b[bp:], sep)`
352			`bp += copy(b[bp:], s)`
353			`}`
354			`return b`
355			`}`
356
357			`// HasPrefix tests whether the byte array s begins with prefix.`
358			`func HasPrefix(s, prefix []byte) bool {`
359			`return len(s) >= len(prefix) && Equal(s[0:len(prefix)], prefix)`
360			`}`
361
362			`// HasSuffix tests whether the byte array s ends with suffix.`
363			`func HasSuffix(s, suffix []byte) bool {`
364			`return len(s) >= len(suffix) && Equal(s[len(s)-len(suffix):], suffix)`
365			`}`
366
367			`// Map returns a copy of the byte array s with all its characters modified`
368			`// according to the mapping function. If mapping returns a negative value, the character is`
369			`// dropped from the string with no replacement. The characters in s and the`
370			`// output are interpreted as UTF-8-encoded Unicode code points.`
371			`func Map(mapping func(r rune) rune, s []byte) []byte {`
372			`// In the worst case, the array can grow when mapped, making`
373			`// things unpleasant. But it's so rare we barge in assuming it's`
374			`// fine. It could also shrink but that falls out naturally.`
375			`maxbytes := len(s) // length of b`
376			`nbytes := 0 // number of bytes encoded in b`
377			`b := make([]byte, maxbytes)`
378			`for i := 0; i < len(s); {`
379			`wid := 1`
380			`r := rune(s[i])`
381			`if r >= utf8.RuneSelf {`
382			`r, wid = utf8.DecodeRune(s[i:])`
383			`}`
384			`r = mapping(r)`
385			`if r >= 0 {`
386			`if nbytes+utf8.RuneLen(r) > maxbytes {`
387			`// Grow the buffer.`
388			`maxbytes = maxbytes*2 + utf8.UTFMax`
389			`nb := make([]byte, maxbytes)`
390			`copy(nb, b[0:nbytes])`
391			`b = nb`
392			`}`
393			`nbytes += utf8.EncodeRune(b[nbytes:maxbytes], r)`
394			`}`
395			`i += wid`
396			`}`
397			`return b[0:nbytes]`
398			`}`
399
400			`// Repeat returns a new byte slice consisting of count copies of b.`
401			`func Repeat(b []byte, count int) []byte {`
402			`nb := make([]byte, len(b)*count)`
403			`bp := 0`
404			`for i := 0; i < count; i++ {`
405			`for j := 0; j < len(b); j++ {`
406			`nb[bp] = b[j]`
407			`bp++`
408			`}`
409			`}`
410			`return nb`
411			`}`
412
413			`// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their upper case.`
414			`func ToUpper(s []byte) []byte { return Map(unicode.ToUpper, s) }`
415
416			`// ToUpper returns a copy of the byte array s with all Unicode letters mapped to their lower case.`
417			`func ToLower(s []byte) []byte { return Map(unicode.ToLower, s) }`
418
419			`// ToTitle returns a copy of the byte array s with all Unicode letters mapped to their title case.`
420			`func ToTitle(s []byte) []byte { return Map(unicode.ToTitle, s) }`
421
422			`// ToUpperSpecial returns a copy of the byte array s with all Unicode letters mapped to their`
423			`// upper case, giving priority to the special casing rules.`
424			`func ToUpperSpecial(_case unicode.SpecialCase, s []byte) []byte {`
425			`return Map(func(r rune) rune { return _case.ToUpper(r) }, s)`
426			`}`
427
428			`// ToLowerSpecial returns a copy of the byte array s with all Unicode letters mapped to their`
429			`// lower case, giving priority to the special casing rules.`
430			`func ToLowerSpecial(_case unicode.SpecialCase, s []byte) []byte {`
431			`return Map(func(r rune) rune { return _case.ToLower(r) }, s)`
432			`}`
433
434			`// ToTitleSpecial returns a copy of the byte array s with all Unicode letters mapped to their`
435			`// title case, giving priority to the special casing rules.`
436			`func ToTitleSpecial(_case unicode.SpecialCase, s []byte) []byte {`
437			`return Map(func(r rune) rune { return _case.ToTitle(r) }, s)`
438			`}`
439
440			`// isSeparator reports whether the rune could mark a word boundary.`
441			`// TODO: update when package unicode captures more of the properties.`
442			`func isSeparator(r rune) bool {`
443			`// ASCII alphanumerics and underscore are not separators`
444			`if r <= 0x7F {`
445			`switch {`
446			`case '0' <= r && r <= '9':`
447			`return false`
448			`case 'a' <= r && r <= 'z':`
449			`return false`
450			`case 'A' <= r && r <= 'Z':`
451			`return false`
452			`case r == '_':`
453			`return false`
454			`}`
455			`return true`
456			`}`
457			`// Letters and digits are not separators`
458			`if unicode.IsLetter(r) \|\| unicode.IsDigit(r) {`
459			`return false`
460			`}`
461			`// Otherwise, all we can do for now is treat spaces as separators.`
462			`return unicode.IsSpace(r)`
463			`}`
464
465			`// BUG(r): The rule Title uses for word boundaries does not handle Unicode punctuation properly.`
466
467			`// Title returns a copy of s with all Unicode letters that begin words`
468			`// mapped to their title case.`
469			`func Title(s []byte) []byte {`
470			`// Use a closure here to remember state.`
471			`// Hackish but effective. Depends on Map scanning in order and calling`
472			`// the closure once per rune.`
473			`prev := ' '`
474			`return Map(`
475			`func(r rune) rune {`
476			`if isSeparator(prev) {`
477			`prev = r`
478			`return unicode.ToTitle(r)`
479			`}`
480			`prev = r`
481			`return r`
482			`},`
483			`s)`
484			`}`
485
486			`// TrimLeftFunc returns a subslice of s by slicing off all leading UTF-8-encoded`
487			`// Unicode code points c that satisfy f(c).`
488			`func TrimLeftFunc(s []byte, f func(r rune) bool) []byte {`
489			`i := indexFunc(s, f, false)`
490			`if i == -1 {`
491			`return nil`
492			`}`
493			`return s[i:]`
494			`}`
495
496			`// TrimRightFunc returns a subslice of s by slicing off all trailing UTF-8`
497			`// encoded Unicode code points c that satisfy f(c).`
498			`func TrimRightFunc(s []byte, f func(r rune) bool) []byte {`
499			`i := lastIndexFunc(s, f, false)`
500			`if i >= 0 && s[i] >= utf8.RuneSelf {`
501			`_, wid := utf8.DecodeRune(s[i:])`
502			`i += wid`
503			`} else {`
504			`i++`
505			`}`
506			`return s[0:i]`
507			`}`
508
509			`// TrimFunc returns a subslice of s by slicing off all leading and trailing`
510			`// UTF-8-encoded Unicode code points c that satisfy f(c).`
511			`func TrimFunc(s []byte, f func(r rune) bool) []byte {`
512			`return TrimRightFunc(TrimLeftFunc(s, f), f)`
513			`}`
514
515			`// IndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.`
516			`// It returns the byte index in s of the first Unicode`
517			`// code point satisfying f(c), or -1 if none do.`
518			`func IndexFunc(s []byte, f func(r rune) bool) int {`
519			`return indexFunc(s, f, true)`
520			`}`
521
522			`// LastIndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points.`
523			`// It returns the byte index in s of the last Unicode`
524			`// code point satisfying f(c), or -1 if none do.`
525			`func LastIndexFunc(s []byte, f func(r rune) bool) int {`
526			`return lastIndexFunc(s, f, true)`
527			`}`
528
529			`// indexFunc is the same as IndexFunc except that if`
530			`// truth==false, the sense of the predicate function is`
531			`// inverted.`
532			`func indexFunc(s []byte, f func(r rune) bool, truth bool) int {`
533			`start := 0`
534			`for start < len(s) {`
535			`wid := 1`
536			`r := rune(s[start])`
537			`if r >= utf8.RuneSelf {`
538			`r, wid = utf8.DecodeRune(s[start:])`
539			`}`
540			`if f(r) == truth {`
541			`return start`
542			`}`
543			`start += wid`
544			`}`
545			`return -1`
546			`}`
547
548			`// lastIndexFunc is the same as LastIndexFunc except that if`
549			`// truth==false, the sense of the predicate function is`
550			`// inverted.`
551			`func lastIndexFunc(s []byte, f func(r rune) bool, truth bool) int {`
552			`for i := len(s); i > 0; {`
553			`r, size := utf8.DecodeLastRune(s[0:i])`
554			`i -= size`
555			`if f(r) == truth {`
556			`return i`
557			`}`
558			`}`
559			`return -1`
560			`}`
561
562			`func makeCutsetFunc(cutset string) func(r rune) bool {`
563			`return func(r rune) bool {`
564			`for _, c := range cutset {`
565			`if c == r {`
566			`return true`
567			`}`
568			`}`
569			`return false`
570			`}`
571			`}`
572
573			`// Trim returns a subslice of s by slicing off all leading and`
574			`// trailing UTF-8-encoded Unicode code points contained in cutset.`
575			`func Trim(s []byte, cutset string) []byte {`
576			`return TrimFunc(s, makeCutsetFunc(cutset))`
577			`}`
578
579			`// TrimLeft returns a subslice of s by slicing off all leading`
580			`// UTF-8-encoded Unicode code points contained in cutset.`
581			`func TrimLeft(s []byte, cutset string) []byte {`
582			`return TrimLeftFunc(s, makeCutsetFunc(cutset))`
583			`}`
584
585			`// TrimRight returns a subslice of s by slicing off all trailing`
586			`// UTF-8-encoded Unicode code points that are contained in cutset.`
587			`func TrimRight(s []byte, cutset string) []byte {`
588			`return TrimRightFunc(s, makeCutsetFunc(cutset))`
589			`}`
590
591			`// TrimSpace returns a subslice of s by slicing off all leading and`
592			`// trailing white space, as defined by Unicode.`
593			`func TrimSpace(s []byte) []byte {`
594			`return TrimFunc(s, unicode.IsSpace)`
595			`}`
596
597			`// Runes returns a slice of runes (Unicode code points) equivalent to s.`
598			`func Runes(s []byte) []rune {`
599			`t := make([]rune, utf8.RuneCount(s))`
600			`i := 0`
601			`for len(s) > 0 {`
602			`r, l := utf8.DecodeRune(s)`
603			`t[i] = r`
604			`i++`
605			`s = s[l:]`
606			`}`
607			`return t`
608			`}`
609
610			`// Replace returns a copy of the slice s with the first n`
611			`// non-overlapping instances of old replaced by new.`
612			`// If n < 0, there is no limit on the number of replacements.`
613			`func Replace(s, old, new []byte, n int) []byte {`
614			`m := 0`
615			`if n != 0 {`
616			`// Compute number of replacements.`
617			`m = Count(s, old)`
618			`}`
619			`if m == 0 {`
620			`// Nothing to do. Just copy.`
621			`t := make([]byte, len(s))`
622			`copy(t, s)`
623			`return t`
624			`}`
625			`if n < 0 \|\| m < n {`
626			`n = m`
627			`}`
628
629			`// Apply replacements to buffer.`
630			`t := make([]byte, len(s)+n*(len(new)-len(old)))`
631			`w := 0`
632			`start := 0`
633			`for i := 0; i < n; i++ {`
634			`j := start`
635			`if len(old) == 0 {`
636			`if i > 0 {`
637			`_, wid := utf8.DecodeRune(s[start:])`
638			`j += wid`
639			`}`
640			`} else {`
641			`j += Index(s[start:], old)`
642			`}`
643			`w += copy(t[w:], s[start:j])`
644			`w += copy(t[w:], new)`
645			`start = j + len(old)`
646			`}`
647			`w += copy(t[w:], s[start:])`
648			`return t[0:w]`
649			`}`
650
651			`// EqualFold reports whether s and t, interpreted as UTF-8 strings,`
652			`// are equal under Unicode case-folding.`
653			`func EqualFold(s, t []byte) bool {`
654			`for len(s) != 0 && len(t) != 0 {`
655			`// Extract first rune from each.`
656			`var sr, tr rune`
657			`if s[0] < utf8.RuneSelf {`
658			`sr, s = rune(s[0]), s[1:]`
659			`} else {`
660			`r, size := utf8.DecodeRune(s)`
661			`sr, s = r, s[size:]`
662			`}`
663			`if t[0] < utf8.RuneSelf {`
664			`tr, t = rune(t[0]), t[1:]`
665			`} else {`
666			`r, size := utf8.DecodeRune(t)`
667			`tr, t = r, t[size:]`
668			`}`
669
670			`// If they match, keep going; if not, return false.`
671
672			`// Easy case.`
673			`if tr == sr {`
674			`continue`
675			`}`
676
677			`// Make sr < tr to simplify what follows.`
678			`if tr < sr {`
679			`tr, sr = sr, tr`
680			`}`
681			`// Fast check for ASCII.`
682			`if tr < utf8.RuneSelf && 'A' <= sr && sr <= 'Z' {`
683			`// ASCII, and sr is upper case. tr must be lower case.`
684			`if tr == sr+'a'-'A' {`
685			`continue`
686			`}`
687			`return false`
688			`}`
689
690			`// General case. SimpleFold(x) returns the next equivalent rune > x`
691			`// or wraps around to smaller values.`
692			`r := unicode.SimpleFold(sr)`
693			`for r != sr && r < tr {`
694			`r = unicode.SimpleFold(r)`
695			`}`
696			`if r == tr {`
697			`continue`
698			`}`
699			`return false`
700			`}`
701
702			`// One string is empty. Are both?`
703			`return len(s) == len(t)`
704			`}`