Method readEscapeSequence

src/parser/token-reader.ts:449–494

()

  }

  private readEscapeSequence(): number | number[] | null {
    const byte = this.scanner.peek();

    if (byte === -1) {
      return null;
    }

    this.scanner.advance();

    switch (byte) {
      case 0x6e:
        return LF; // \n -> LF
      case 0x72:
        return CR; // \r -> CR
      case 0x74:
        return TAB; // \t -> TAB
      case 0x62:
        return BS; // \b -> BS
      case 0x66:
        return FF; // \f -> FF
      case CHAR_PARENTHESIS_OPEN:
        return CHAR_PARENTHESIS_OPEN; // \( -> (
      case CHAR_PARENTHESIS_CLOSE:
        return CHAR_PARENTHESIS_CLOSE; // \) -> )
      case CHAR_BACKSLASH:
        return CHAR_BACKSLASH; // \\ -> \
      case CR:
        // Line continuation: \ at end of line
        if (this.scanner.peek() === LF) {
          this.scanner.advance();
        }

        return null;
      case LF:
        // Line continuation
        return null;
      default:
        // Check for octal
        if (byte >= DIGIT_0 && byte <= 0x37) {
          return this.readOctalEscape(byte);
        }

        // Unknown escape - return literal character
        return byte;
    }
  }

  private readOctalEscape(firstDigit: number): number {
    let value = firstDigit - DIGIT_0;