/usr/share/gocode/src/github.com/dlclark/regexp2/replace.go is in golang-github-dlclark-regexp2-dev 1.1.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 | package regexp2
import (
"bytes"
"errors"
"github.com/dlclark/regexp2/syntax"
)
const (
replaceSpecials = 4
replaceLeftPortion = -1
replaceRightPortion = -2
replaceLastGroup = -3
replaceWholeString = -4
)
// MatchEvaluator is a function that takes a match and returns a replacement string to be used
type MatchEvaluator func(Match) string
// Three very similar algorithms appear below: replace (pattern),
// replace (evaluator), and split.
// Replace Replaces all occurrences of the regex in the string with the
// replacement pattern.
//
// Note that the special case of no matches is handled on its own:
// with no matches, the input string is returned unchanged.
// The right-to-left case is split out because StringBuilder
// doesn't handle right-to-left string building directly very well.
func replace(regex *Regexp, data *syntax.ReplacerData, evaluator MatchEvaluator, input string, startAt, count int) (string, error) {
if count < -1 {
return "", errors.New("Count too small")
}
if count == 0 {
return "", nil
}
m, err := regex.FindStringMatchStartingAt(input, startAt)
if err != nil {
return "", err
}
if m == nil {
return input, nil
}
buf := &bytes.Buffer{}
text := m.text
if !regex.RightToLeft() {
prevat := 0
for m != nil {
if m.Index != prevat {
buf.WriteString(string(text[prevat:m.Index]))
}
prevat = m.Index + m.Length
if evaluator == nil {
replacementImpl(data, buf, m)
} else {
buf.WriteString(evaluator(*m))
}
count--
if count == 0 {
break
}
m, err = regex.FindNextMatch(m)
if err != nil {
return "", nil
}
}
if prevat < len(text) {
buf.WriteString(string(text[prevat:]))
}
} else {
prevat := len(text)
var al []string
for m != nil {
if m.Index+m.Length != prevat {
al = append(al, string(text[m.Index+m.Length:prevat]))
}
prevat = m.Index
if evaluator == nil {
replacementImplRTL(data, &al, m)
} else {
al = append(al, evaluator(*m))
}
count--
if count == 0 {
break
}
m, err = regex.FindNextMatch(m)
if err != nil {
return "", nil
}
}
if prevat > 0 {
buf.WriteString(string(text[:prevat]))
}
for i := len(al) - 1; i >= 0; i-- {
buf.WriteString(al[i])
}
}
return buf.String(), nil
}
// Given a Match, emits into the StringBuilder the evaluated
// substitution pattern.
func replacementImpl(data *syntax.ReplacerData, buf *bytes.Buffer, m *Match) {
for _, r := range data.Rules {
if r >= 0 { // string lookup
buf.WriteString(data.Strings[r])
} else if r < -replaceSpecials { // group lookup
m.groupValueAppendToBuf(-replaceSpecials-1-r, buf)
} else {
switch -replaceSpecials - 1 - r { // special insertion patterns
case replaceLeftPortion:
for i := 0; i < m.Index; i++ {
buf.WriteRune(m.text[i])
}
case replaceRightPortion:
for i := m.Index + m.Length; i < len(m.text); i++ {
buf.WriteRune(m.text[i])
}
case replaceLastGroup:
m.groupValueAppendToBuf(m.GroupCount()-1, buf)
case replaceWholeString:
for i := 0; i < len(m.text); i++ {
buf.WriteRune(m.text[i])
}
}
}
}
}
func replacementImplRTL(data *syntax.ReplacerData, al *[]string, m *Match) {
l := *al
buf := &bytes.Buffer{}
for _, r := range data.Rules {
buf.Reset()
if r >= 0 { // string lookup
l = append(l, data.Strings[r])
} else if r < -replaceSpecials { // group lookup
m.groupValueAppendToBuf(-replaceSpecials-1-r, buf)
l = append(l, buf.String())
} else {
switch -replaceSpecials - 1 - r { // special insertion patterns
case replaceLeftPortion:
for i := 0; i < m.Index; i++ {
buf.WriteRune(m.text[i])
}
case replaceRightPortion:
for i := m.Index + m.Length; i < len(m.text); i++ {
buf.WriteRune(m.text[i])
}
case replaceLastGroup:
m.groupValueAppendToBuf(m.GroupCount()-1, buf)
case replaceWholeString:
for i := 0; i < len(m.text); i++ {
buf.WriteRune(m.text[i])
}
}
l = append(l, buf.String())
}
}
*al = l
}
|