Method readHexString

src/parser/token-reader.ts:530–579

(position: number)

  }

  private readHexString(position: number): StringToken {
    const bytes: number[] = [];
    let pendingNibble: number | null = null;

    while (true) {
      const byte = this.scanner.peek();

      if (byte === -1 || byte === CHAR_ANGLE_BRACKET_CLOSE) {
        // EOF or >
        if (byte === CHAR_ANGLE_BRACKET_CLOSE) {
          this.scanner.advance();
        }

        break;
      }

      this.scanner.advance();

      // Skip whitespace inside hex string
      if (WHITESPACE.has(byte)) {
        continue;
      }

      if (isHexDigit(byte)) {
        const nibble = hexValue(byte);

        if (pendingNibble === null) {
          pendingNibble = nibble;
        } else {
          bytes.push((pendingNibble << 4) | nibble);
          pendingNibble = null;
        }
      }

      // Invalid character - skip with warning (lenient)
      // TODO: Add warning callback
    }

    // Odd number of hex digits - pad with 0
    if (pendingNibble !== null) {
      bytes.push(pendingNibble << 4);
    }

    return {
      type: "string",
      value: new Uint8Array(bytes),
      format: "hex",
      position,
    };
  }

  private readClosingAngle(position: number): DelimiterToken {
    this.scanner.advance(); // Skip first >