nl_tokens: / * 根据className获取dom集合
pl_tokens: function getElementsByClassName ( node , classname ) { if ( node . getElementsByClassName ) { // use native implementation if available return node . getElementsByClassName ( classname ) ; } else { return ( function getElementsByClass ( searchClass , <mask> ) { if ( node == null ) node = document ; var classElements = [ ] , els = node . getElementsByTagName ( "*" ) , elsLen = els . length , pattern = new RegExp ( "(^|\\s)" + searchClass + "(\\s|$)" ) , i , j ; for ( i = 0 , j = 0 ; i < elsLen ; i ++ ) { if ( pattern . test ( els [ i ] . className ) ) { classElements [ j ] = els [ i ] ; j ++ ; } } return classElements ; } ) ( classname , node ) ; } }