internal ConstantListItem(Object term, ConstantListItem prev){
   this.prev = prev;
   this.term = term;
 }
 private object PPScanExpr()
 {
     object obj2;
     OpListItem prev = new OpListItem(JSToken.None, OpPrec.precNone, null);
     ConstantListItem item2 = new ConstantListItem(this.PPScanConstant(), null);
     while (true)
     {
         this.GetNextToken();
         if (!IsPPOperator(this.currentToken.token))
         {
             goto Label_00E4;
         }
         OpPrec pPOperatorPrecedence = GetPPOperatorPrecedence(this.currentToken.token);
         while (pPOperatorPrecedence < prev._prec)
         {
             obj2 = this.PPGetValue(prev._operator, item2.prev.term, item2.term);
             prev = prev._prev;
             item2 = item2.prev.prev;
             item2 = new ConstantListItem(obj2, item2);
         }
         prev = new OpListItem(this.currentToken.token, pPOperatorPrecedence, prev);
         item2 = new ConstantListItem(this.PPScanConstant(), item2);
     }
 Label_00AB:
     obj2 = this.PPGetValue(prev._operator, item2.prev.term, item2.term);
     prev = prev._prev;
     item2 = item2.prev.prev;
     item2 = new ConstantListItem(obj2, item2);
 Label_00E4:
     if (prev._operator != JSToken.None)
     {
         goto Label_00AB;
     }
     this.currentPos = this.currentToken.startPos;
     return item2.term;
 }
예제 #3
0
      private Object PPScanExpr(){
        OpListItem opsStack = new OpListItem(JSToken.None, OpPrec.precNone, null); // dummy element
        ConstantListItem termStack = new ConstantListItem(PPScanConstant(), null);
        Object value;
        for (;;){
          GetNextToken();
          if (JSScanner.IsPPOperator(this.currentToken.token)){

            OpPrec prec = JSScanner.GetPPOperatorPrecedence(this.currentToken.token);
            while (prec < opsStack._prec){
              //Console.Out.WriteLine("lower prec or same and left assoc");
              value = PPGetValue(opsStack._operator, termStack.prev.term, termStack.term);

              // pop the operator stack
              opsStack = opsStack._prev;
              // pop the term stack twice
              termStack = termStack.prev.prev;
              // push node onto the stack
              termStack = new ConstantListItem(value, termStack);
            }
            // the current operator has higher precedence that every scanned operators on the stack, or
            // it has the same precedence as the one at the top of the stack and it is right associative
            // push the operator onto the operators stack
            opsStack = new OpListItem(this.currentToken.token, prec, opsStack);
            // push new term
            termStack = new ConstantListItem(PPScanConstant(), termStack);
          }else{
            //Console.Out.WriteLine("unwinding stack");
            // there are still operators to be processed
            while (opsStack._operator != JSToken.None){
              // make the ast operator node
              value = PPGetValue(opsStack._operator, termStack.prev.term, termStack.term);

              // pop the operator stack
              opsStack = opsStack._prev;
              // pop the term stack twice
              termStack = termStack.prev.prev;

              // push node onto the stack
              termStack = new ConstantListItem(value, termStack);
            }

            // reset position into stream
            this.currentPos = this.currentToken.startPos;

            break; // done
          }
        }

        Debug.Assert(termStack.prev == null);
        return termStack.term;
      }
 internal ConstantListItem(object term, ConstantListItem prev)
 {
     this.prev = prev;
     this.term = term;
 }