nl_tokens: In general keep in mind that the stack - based nature of this visitor is reverse - polish - notation form . I . e . in a sequence of calls to walk or invoke they ll actually get visited in LIFO order .
pl_tokens: function TreeWalker ( ast , recv ) { var self = this ; this . ast = ast ; this . recv = recv ; this . stack = [ { traverse : ast , parent : undefined , name : undefined } , { fun : function ( ) { if ( self . hasProp ( self . recv , 'finished' ) && Function === self . recv . finished . constructor ) { return self . recv . finished ( ) ; } } } ] ; this . <mask> = undefined ; }