diff options
| author | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
|---|---|---|
| committer | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
| commit | c6cc0108ca7738023b45e0eeac0fa2390532dd93 (patch) | |
| tree | 36890e6cd3091bbab8efbe686cc56f467f645bfd /vendor/github.com/dlclark/regexp2/syntax/escape.go | |
| parent | 0130404a1dc663d4aa68d780c9bcb23a4243e68d (diff) | |
| download | jbmafp-master.tar.gz | |
Diffstat (limited to 'vendor/github.com/dlclark/regexp2/syntax/escape.go')
| -rw-r--r-- | vendor/github.com/dlclark/regexp2/syntax/escape.go | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/vendor/github.com/dlclark/regexp2/syntax/escape.go b/vendor/github.com/dlclark/regexp2/syntax/escape.go new file mode 100644 index 0000000..609df10 --- /dev/null +++ b/vendor/github.com/dlclark/regexp2/syntax/escape.go @@ -0,0 +1,94 @@ +package syntax + +import ( + "bytes" + "strconv" + "strings" + "unicode" +) + +func Escape(input string) string { + b := &bytes.Buffer{} + for _, r := range input { + escape(b, r, false) + } + return b.String() +} + +const meta = `\.+*?()|[]{}^$# ` + +func escape(b *bytes.Buffer, r rune, force bool) { + if unicode.IsPrint(r) { + if strings.IndexRune(meta, r) >= 0 || force { + b.WriteRune('\\') + } + b.WriteRune(r) + return + } + + switch r { + case '\a': + b.WriteString(`\a`) + case '\f': + b.WriteString(`\f`) + case '\n': + b.WriteString(`\n`) + case '\r': + b.WriteString(`\r`) + case '\t': + b.WriteString(`\t`) + case '\v': + b.WriteString(`\v`) + default: + if r < 0x100 { + b.WriteString(`\x`) + s := strconv.FormatInt(int64(r), 16) + if len(s) == 1 { + b.WriteRune('0') + } + b.WriteString(s) + break + } + b.WriteString(`\u`) + b.WriteString(strconv.FormatInt(int64(r), 16)) + } +} + +func Unescape(input string) (string, error) { + idx := strings.IndexRune(input, '\\') + // no slashes means no unescape needed + if idx == -1 { + return input, nil + } + + buf := bytes.NewBufferString(input[:idx]) + // get the runes for the rest of the string -- we're going full parser scan on this + + p := parser{} + p.setPattern(input[idx+1:]) + for { + if p.rightMost() { + return "", p.getErr(ErrIllegalEndEscape) + } + r, err := p.scanCharEscape() + if err != nil { + return "", err + } + buf.WriteRune(r) + // are we done? + if p.rightMost() { + return buf.String(), nil + } + + r = p.moveRightGetChar() + for r != '\\' { + buf.WriteRune(r) + if p.rightMost() { + // we're done, no more slashes + return buf.String(), nil + } + // keep scanning until we get another slash + r = p.moveRightGetChar() + } + } +} |
