90 lines
1.6 KiB
Go
90 lines
1.6 KiB
Go
package zenutil
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// Unescape is internal.
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func Unescape(s string) string {
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// Apply rules described in:
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// https://developer.gnome.org/glib/stable/glib-String-Utility-Functions.html#g-strescape
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const (
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initial = iota
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escape1
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escape2
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escape3
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)
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var oct byte
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var res []byte
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state := initial
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for _, b := range []byte(s) {
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switch state {
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case initial:
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switch b {
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case '\\':
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state = escape1
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default:
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res = append(res, b)
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state = initial
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}
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case escape1:
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switch b {
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case '0', '1', '2', '3', '4', '5', '6', '7':
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oct = b - '0'
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state = escape2
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case 'b':
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res = append(res, '\b')
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state = initial
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case 'f':
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res = append(res, '\f')
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state = initial
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case 'n':
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res = append(res, '\n')
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state = initial
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case 'r':
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res = append(res, '\r')
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state = initial
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case 't':
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res = append(res, '\t')
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state = initial
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case 'v':
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res = append(res, '\v')
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state = initial
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default:
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res = append(res, b)
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state = initial
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}
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case escape2:
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switch b {
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case '0', '1', '2', '3', '4', '5', '6', '7':
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oct = oct<<3 | (b - '0')
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state = escape3
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case '\\':
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res = append(res, oct)
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state = escape1
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default:
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res = append(res, oct, b)
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state = initial
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}
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case escape3:
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switch b {
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case '0', '1', '2', '3', '4', '5', '6', '7':
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oct = oct<<3 | (b - '0')
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res = append(res, oct)
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state = initial
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case '\\':
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res = append(res, oct)
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state = escape1
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default:
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res = append(res, oct, b)
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state = initial
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}
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}
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}
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if state == escape2 || state == escape3 {
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res = append(res, oct)
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}
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return string(res)
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}
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