vendors/tempy.js/parse
    function parse(pattern, isSub) {
      assertValidPattern(pattern);
      var options = this.options;
      if (pattern === "**") {
        if (!options.noglobstar)
          return GLOBSTAR;
        else
          pattern = "*";
      }
      if (pattern === "")
        return "";
      var re = "";
      var hasMagic = !!options.nocase;
      var escaping = false;
      var patternListStack = [];
      var negativeLists = [];
      var stateChar;
      var inClass = false;
      var reClassStart = -1;
      var classStart = -1;
      var patternStart = pattern.charAt(0) === "." ? "" : options.dot ? "(?!(?:^|\\/)\\.{1,2}(?:$|\\/))" : "(?!\\.)";
      var self = this;
      function clearStateChar() {
        if (stateChar) {
          switch (stateChar) {
            case "*":
              re += star;
              hasMagic = true;
              break;
            case "?":
              re += qmark;
              hasMagic = true;
              break;
            default:
              re += "\\" + stateChar;
              break;
          }
          self.debug("clearStateChar %j %j", stateChar, re);
          stateChar = false;
        }
      }
      for (var i = 0, len = pattern.length, c; i < len && (c = pattern.charAt(i)); i++) {
        this.debug("%s	%s %s %j", pattern, i, re, c);
        if (escaping && reSpecials[c]) {
          re += "\\" + c;
          escaping = false;
          continue;
        }
        switch (c) {
          case "/": {
            return false;
          }
          case "\\":
            clearStateChar();
            escaping = true;
            continue;
          case "?":
          case "*":
          case "+":
          case "@":
          case "!":
            this.debug("%s	%s %s %j <-- stateChar", pattern, i, re, c);
            if (inClass) {
              this.debug("  in class");
              if (c === "!" && i === classStart + 1)
                c = "^";
              re += c;
              continue;
            }
            self.debug("call clearStateChar %j", stateChar);
            clearStateChar();
            stateChar = c;
            if (options.noext)
              clearStateChar();
            continue;
          case "(":
            if (inClass) {
              re += "(";
              continue;
            }
            if (!stateChar) {
              re += "\\(";
              continue;
            }
            patternListStack.push({
              type: stateChar,
              start: i - 1,
              reStart: re.length,
              open: plTypes[stateChar].open,
              close: plTypes[stateChar].close
            });
            re += stateChar === "!" ? "(?:(?!(?:" : "(?:";
            this.debug("plType %j %j", stateChar, re);
            stateChar = false;
            continue;
          case ")":
            if (inClass || !patternListStack.length) {
              re += "\\)";
              continue;
            }
            clearStateChar();
            hasMagic = true;
            var pl = patternListStack.pop();
            re += pl.close;
            if (pl.type === "!") {
              negativeLists.push(pl);
            }
            pl.reEnd = re.length;
            continue;
          case "|":
            if (inClass || !patternListStack.length || escaping) {
              re += "\\|";
              escaping = false;
              continue;
            }
            clearStateChar();
            re += "|";
            continue;
          case "[":
            clearStateChar();
            if (inClass) {
              re += "\\" + c;
              continue;
            }
            inClass = true;
            classStart = i;
            reClassStart = re.length;
            re += c;
            continue;
          case "]":
            if (i === classStart + 1 || !inClass) {
              re += "\\" + c;
              escaping = false;
              continue;
            }
            var cs = pattern.substring(classStart + 1, i);
            try {
              RegExp("[" + cs + "]");
            } catch (er) {
              var sp = this.parse(cs, SUBPARSE);
              re = re.substr(0, reClassStart) + "\\[" + sp[0] + "\\]";
              hasMagic = hasMagic || sp[1];
              inClass = false;
              continue;
            }
            hasMagic = true;
            inClass = false;
            re += c;
            continue;
          default:
            clearStateChar();
            if (escaping) {
              escaping = false;
            } else if (reSpecials[c] && !(c === "^" && inClass)) {
              re += "\\";
            }
            re += c;
        }
      }
      if (inClass) {
        cs = pattern.substr(classStart + 1);
        sp = this.parse(cs, SUBPARSE);
        re = re.substr(0, reClassStart) + "\\[" + sp[0];
        hasMagic = hasMagic || sp[1];
      }
      for (pl = patternListStack.pop(); pl; pl = patternListStack.pop()) {
        var tail = re.slice(pl.reStart + pl.open.length);
        this.debug("setting tail", re, pl);
        tail = tail.replace(/((?:\\{2}){0,64})(\\?)\|/g, function(_, $1, $2) {
          if (!$2) {
            $2 = "\\";
          }
          return $1 + $1 + $2 + "|";
        });
        this.debug("tail=%j\n   %s", tail, tail, pl, re);
        var t = pl.type === "*" ? star : pl.type === "?" ? qmark : "\\" + pl.type;
        hasMagic = true;
        re = re.slice(0, pl.reStart) + t + "\\(" + tail;
      }
      clearStateChar();
      if (escaping) {
        re += "\\\\";
      }
      var addPatternStart = false;
      switch (re.charAt(0)) {
        case "[":
        case ".":
        case "(":
          addPatternStart = true;
      }
      for (var n = negativeLists.length - 1; n > -1; n--) {
        var nl = negativeLists[n];
        var nlBefore = re.slice(0, nl.reStart);
        var nlFirst = re.slice(nl.reStart, nl.reEnd - 8);
        var nlLast = re.slice(nl.reEnd - 8, nl.reEnd);
        var nlAfter = re.slice(nl.reEnd);
        nlLast += nlAfter;
        var openParensBefore = nlBefore.split("(").length - 1;
        var cleanAfter = nlAfter;
        for (i = 0; i < openParensBefore; i++) {
          cleanAfter = cleanAfter.replace(/\)[+*?]?/, "");
        }
        nlAfter = cleanAfter;
        var dollar = "";
        if (nlAfter === "" && isSub !== SUBPARSE) {
          dollar = "$";
        }
        var newRe = nlBefore + nlFirst + nlAfter + dollar + nlLast;
        re = newRe;
      }
      if (re !== "" && hasMagic) {
        re = "(?=.)" + re;
      }
      if (addPatternStart) {
        re = patternStart + re;
      }
      if (isSub === SUBPARSE) {
        return [re, hasMagic];
      }
      if (!hasMagic) {
        return globUnescape(pattern);
      }
      var flags = options.nocase ? "i" : "";
      try {
        var regExp = new RegExp("^" + re + "$", flags);
      } catch (er) {
        return new RegExp("$.");
      }
      regExp._glob = pattern;
      regExp._src = re;
      return regExp;
    }