Function escape

test/angular/1.4/angular.js:11206–11208

(ch)

        escapedEndRegexp = new RegExp(endSymbol.replace(/./g, escape), 'g');

    function escape(ch) {
      return '\\\\\\' + ch;
    }

    function unescapeText(text) {
      return text.replace(escapedStartRegexp, startSymbol).