Function toRegex

lib/codemirror/addon/mode/simple.js:66–76

(val, caret)

  }

  function toRegex(val, caret) {
    if (!val) return /(?:)/;
    var flags = "";
    if (val instanceof RegExp) {
      if (val.ignoreCase) flags = "i";
      val = val.source;
    } else {
      val = String(val);
    }
    return new RegExp((caret === false ? "" : "^") + "(?:" + val + ")", flags);
  }

  function asToken(val) {
    if (!val) return null;