core/event.js
function _getMatcher (element) {
  if (_matcher) {
    return _matcher;
  }

  if (element.matches) {
    _matcher = element.matches;
    return _matcher;
  }

  if (element.webkitMatchesSelector) {
    _matcher = element.webkitMatchesSelector;
    return _matcher;
  }

  if (element.mozMatchesSelector) {
    _matcher = element.mozMatchesSelector;
    return _matcher;
  }

  if (element.msMatchesSelector) {
    _matcher = element.msMatchesSelector;
    return _matcher;
  }

  if (element.oMatchesSelector) {
    _matcher = element.oMatchesSelector;
    return _matcher;
  }

  // if it doesn't match a native browser method
  // fall back to the delegator function
  _matcher = Delegator.matchesSelector;
  return _matcher;
}
function _getMatcher (element) {
  if (_matcher) {
    return _matcher;
  }

  if (element.matches) {
    _matcher = element.matches;
    return _matcher;
  }

  if (element.webkitMatchesSelector) {
    _matcher = element.webkitMatchesSelector;
    return _matcher;
  }

  if (element.mozMatchesSelector) {
    _matcher = element.mozMatchesSelector;
    return _matcher;
  }

  if (element.msMatchesSelector) {
    _matcher = element.msMatchesSelector;
    return _matcher;
  }

  if (element.oMatchesSelector) {
    _matcher = element.oMatchesSelector;
    return _matcher;
  }

  // if it doesn't match a native browser method
  // fall back to the delegator function
  _matcher = Delegator.matchesSelector;
  return _matcher;
}
function _getMatcher ( element ) { if ( _matcher ) { return _matcher ; } if ( element . matches ) { _matcher = element . matches ; return _matcher ; } if ( element . webkitMatchesSelector ) { _matcher = element . webkitMatchesSelector ; return _matcher ; } if ( element . mozMatchesSelector ) { _matcher = element . mozMatchesSelector ; return _matcher ; } if ( element . msMatchesSelector ) { _matcher = element . msMatchesSelector ; return _matcher ; } if ( element . oMatchesSelector ) { _matcher = element . oMatchesSelector ; return _matcher ; } // if it doesn't match a native browser method // fall back to the delegator function _matcher = Delegator . matchesSelector ; return _matcher ; }
returns function to use for determining if an element
matches a query selector

@returns {Function}
returns function to use for determining if an element matches a query selector