nl_tokens: http : // jsperf . com / copy - array - inline
pl_tokens: function arrCopy ( arr , offset ) { offset = offset || 0 ; var len = Math . max ( 0 , arr . <mask> - offset ) ; var newArr = new Array ( len ) ; for ( var ii = 0 ; ii < len ; ii ++ ) { newArr [ ii ] = arr [ ii + offset ] ; } return newArr ; }