Method scanRegex

packages/compiler/src/expression_parser/lexer.ts:692–732

(tokenStart: number)

  }

  private scanRegex(tokenStart: number): Token {
    this.advance();
    const textStart = this.index;
    let inEscape = false;
    let inCharacterClass = false;

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

      if (peek === chars.$EOF) {
        return this.error('Unterminated regular expression', 0);
      }

      if (inEscape) {
        inEscape = false;
      } else if (peek === chars.$BACKSLASH) {
        inEscape = true;
      } else if (peek === chars.$LBRACKET) {
        inCharacterClass = true;
      } else if (peek === chars.$RBRACKET) {
        inCharacterClass = false;
      } else if (peek === chars.$SLASH && !inCharacterClass) {
        break;
      }
      this.advance();
    }

    // Note that we want the text without the slashes,
    // but we still want the slashes to be part of the span.
    const value = this.input.substring(textStart, this.index);
    this.advance();
    const bodyToken = newRegExpBodyToken(tokenStart, this.index, value);
    const flagsToken = this.scanRegexFlags(this.index);

    if (flagsToken !== null) {
      this.tokens.push(bodyToken);
      return flagsToken;
    }

    return bodyToken;
  }

  private scanRegexFlags(start: number): Token | null {
    if (!chars.isAsciiLetter(this.peek)) {