function quote(s) {
    /*
     * ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a
     * string literal except for the closing quote character, backslash,
     * carriage return, line separator, paragraph separator, and line feed.
     * Any character may appear in the form of an escape sequence.
     *
     * For portability, we also escape escape all control and non-ASCII
     * characters. Note that "\0" and "\v" escape sequences are not used
     * because JSHint does not like the first and IE the second.
     */
     return '"' + s
      .replace(/\\/g, '\\\\')  // backslash
      .replace(/"/g, '\\"')    // closing quote character
      .replace(/\x08/g, '\\b') // backspace
      .replace(/\t/g, '\\t')   // horizontal tab
      .replace(/\n/g, '\\n')   // line feed
      .replace(/\f/g, '\\f')   // form feed
      .replace(/\r/g, '\\r')   // carriage return
      .replace(/[\x00-\x07\x0B\x0E-\x1F\x80-\uFFFF]/g, escape)
      + '"';
  }
Filter parser object.
This is generated from {@code filterparser.pegjs} and pasted into here.

<code>
try {
  var result = wtf.db.FilterParser.parse('expression');
} catch (e) {
  if (e instanceof wtf.db.FilterParser.SyntaxError) {
    // ...
  }
}
</code>

@type {!{
  parse: function(string, (string|undefined)):!Object,
  SyntaxError: Function
}}