Function parseUnit

src/pkg/utils/regex_to_glob.ts:652–680

()

  // ----- Unit parsing ----- 单元解析
  function parseUnit(): Unit | null {
    const ch: string = next();

    if (ch === "\\") {
      const esc: string = next();
      if (!esc) return null; // Unterminated escape 转义未结束
      if (esc === "b" || esc === "B")
        return { glob: "", baseGlob: "", canRepeat: false, min: 0, isLiteral: false, varLen: false }; // word boundary 词边界
      if ("wdsWDS".includes(esc))
        return { glob: "?", baseGlob: "?", canRepeat: true, min: 1, isLiteral: false, varLen: false }; // class-like escapes 类似 \w \d \s
      const lit: string = escapeGlobLiteral(esc); // includes '*'/'?' → '?' 其他转义（含 '*'/'?'）→ 字面（映射规则里 '*'/'?' → '?'
      return { glob: lit, baseGlob: lit, canRepeat: true, min: 1, isLiteral: true, varLen: false };
    }

    if (ch === ".") return { glob: "?", baseGlob: "?", canRepeat: true, min: 1, isLiteral: false, varLen: false };
    if (ch === "[") return parseCharClass();
    if (ch === "(") return parseGroup();
    if (ch === "^" || ch === "$")
      return { glob: "", baseGlob: "", canRepeat: false, min: 0, isLiteral: false, varLen: false }; // anchors 锚点零宽

    // 頂層遇到孤立的關閉符直接判定為無效語法
    if (ch === ")" || ch === "]") {
      return null;
    }

    // Plain literal character / 普通字面量字符
    const lit: string = escapeGlobLiteral(ch);
    return { glob: lit, baseGlob: lit, canRepeat: true, min: 1, isLiteral: true, varLen: false };
  }

  // ----- Quantifiers ----- 数量词应用
  function applyQuantifier(unit: Unit | null): string | null {