code: function ( arg ) {
  		var result;
  
  		if ( !regex.selector_complex.test( arg ) ) {
  			if ( regex.hash.test( arg ) ) {
  				result = document.getElementById( arg.replace( regex.hash, "" ) ) || undefined;
  			}
  			else if ( regex.klass.test( arg ) ) {
  				result = array.cast( document.getElementsByClassName( arg.replace( regex.klass, "" ) ) );
  			}
  			else if ( regex.word.test( arg ) ) {
  				result = array.cast( document.getElementsByTagName( arg ) );
  			}
  			else {
  				result = array.cast( document.querySelectorAll( arg ) );
  			}
  		}
  		else {
  			result = array.cast( document.querySelectorAll( arg ) );
  		}
  
  		return result;
  	}
docs: Queries DOM with fastest method
  
  @method dom
  @param  {String} arg DOM query
  @return {Mixed}      undefined, Element, or Array of Elements