Function DecodeString

strings.go:189–250

DecodeString accepts a raw string as it might be found in some JavaScript source code, and converts any escape sequences. E.g: foo\x3dbar -> foo=bar // Hex escapes foo\u003Dbar -> foo=bar // Unicode escapes foo\u{003D}bar -> foo=bar // Braced unicode escapes foo\075bar -> foo=bar // Octal escape foo

(in string)

//   foo\075bar -> foo=bar // Octal escape
//   foo\"bar -> foo"bar // Single character escapes
func DecodeString(in string) string {
	in = dequote(in)
	l := newStringLexer(in)

	validHex := "0123456789abcdefABCDEF"

	for !l.done {
		l.AcceptUntil('\\')
		l.Emit(itemString)

		if l.done {
			break
		}

		// Ignore the backslash
		l.Next()
		l.Ignore()

		switch l.Next() {
		case 'b', 'f', 'n', 'r', 't', 'v', '\'', '"', '\\':
			l.Emit(itemSingleEscape)
		case '0':
			// It's a \0 (null)
			if !unicode.IsDigit(l.Peek()) {
				l.Emit(itemSingleEscape)
				continue
			}
			// It's an octal escape
			l.AcceptRun("01234567")
			l.Emit(itemOctalEscape)
		case 'x':
			// ignore the x
			l.Ignore()

			// Exactly 2 hex digits
			if l.AcceptN(validHex, 2) {
				l.Emit(itemHexEscape)
			}
		case 'u':
			// ignore the u
			l.Ignore()

			// e.g. \u{00003d}
			if l.Accept("{") {
				l.Ignore()
				l.AcceptRun(validHex)
				l.Emit(itemCodepointEscape)
				if l.Accept("}") {
					l.Ignore()
				}
			}

			// e.g. \u003d
			if l.AcceptN(validHex, 4) {
				l.Emit(itemUnicodeEscape)
			}

		}