code: function choice ( parserSyntax ) {
  				return function () {
  					var i, result;
  
  					for ( i = 0; i < parserSyntax.length; i++ ) {
  						result = parserSyntax[i]();
  
  						if ( result !== null ) {
  							return result;
  						}
  					}
  
  					return null;
  				};
  			}
docs: Try parsers until one works, if none work return null