html-tools.js
function (scanner, matcher) {
  var start = scanner.pos;
  var result = matcher(scanner);
  scanner.pos = start;
  return result;
}
function (scanner, matcher) {
  var start = scanner.pos;
  var result = matcher(scanner);
  scanner.pos = start;
  return result;
}
function ( scanner , matcher ) { var start = scanner . pos ; var result = matcher ( scanner ) ; scanner . pos = start ; return result ; }
Run a provided "matcher" function but reset the current position afterwards. Fatal failure of the matcher is not suppressed.
Run a provided matcher function but reset the current position afterwards . Fatal failure of the matcher is not suppressed .