//very Important function-=-Self Explainatory private void PopConnectPush() { ExpTreeNode Temp = OpStack.Pop(); //Get Top operator and associate the operands //Find here if the Operator is "=" - then dont make the Symbol InVALID--Give some value Temp._right = NodeStack.Pop(); //Get Left and right from NodeStck if (Temp._value.ToString() == "=") { ExpTreeNode TmpLeft = NodeStack.Pop(); //Now this needs to be Symbol with no Sub tree if (TmpLeft._ndType != ExpTreeNode.NodeType.Symbol) { ErrorException Er = new ErrorException("Operator = at the wrong Place Left Operand must be lvalue "); throw Er; } if (TmpLeft._left == null || TmpLeft._right == null) { TmpLeft._value = -1; //SYMBOL TO BE CALCULATED Temp._left = TmpLeft; NodeStack.Push(Temp); // puch the sub tree on the stack return; } else { ErrorException Er = new ErrorException("Operator = at the Wrong Place Left Operand must be lvalue"); throw Er; } } Temp._left = NodeStack.Pop(); NodeStack.Push(Temp); // puch the sub tree on the stack }
public bool SetExpression(string _exp) { //Clear the Previous Exp _exp_parser.Clear(); //now Parse the Exp _exp_tree = _exp_parser.ParseExpression(_exp); return true; }
public bool SetExpression(string _exp) { //Clear the Previous Exp _exp_parser.Clear(); //Now Parse the Exp _exp_tree = _exp_parser.ParseExpression(_exp); return(true); }
private double _evaluate_exp(ExpTreeNode n) { if (n == null) { ErrorException Er = new ErrorException("No Expression Tree to Evaluate "); throw Er; } double x, y; if (n._ndType == ExpTreeNode.NodeType.Operator) { x = _evaluate_exp(n._left); y = _evaluate_exp(n._right); return((_OpInst == null) ? ApplyOp(n._value.ToString(), x, y):_OpInst.ApplyOp(n._value.ToString(), x, y)); } return(System.Convert.ToDouble(n._value)); }
private double _evaluate_exp(ExpTreeNode n) { if(n== null) { ErrorException Er = new ErrorException("No Expression Tree to Evaluate "); throw Er; } double x,y; if (n._ndType == ExpTreeNode.NodeType.Operator) { x = _evaluate_exp(n._left); y = _evaluate_exp(n._right); return (_OpInst == null) ? ApplyOp(n._value.ToString(),x,y):_OpInst.ApplyOp(n._value.ToString(),x,y); } return (System.Convert.ToDouble(n._value)) ; }
//not Implemented public string ReMakeExpression(ExpTreeNode Tree) { //Doing nothing right now return ""; }
public void Push(ExpTreeNode f) { data[top++] = f; }
public TreeStack(int size) { data = new ExpTreeNode[size]; top = 0; }
//Parse Expression funtion main funtion //Creating the Exp tree from the Infix Expression public ExpTreeNode ParseExpression(string exp) { //Check for the Expresiioon validity if(!Isvalid_Exp(exp)) { //Throw an Error Saying Commas are not proper ErrorException Er = new ErrorException("Operators ( or ) are not at the right places"); throw Er; //Is c# need this return after that -- i dont think so but anyway } //Fill ur _exp Variable will need that _exp = exp; NextToken(); do { //The errors that might come would be from stack //If that went wrong -- gone case -- What use rwould do //no USer specific Errors from this funtion switch(current) { case Token.Literal: //CreateLeafNode and push it on the stack ExpTreeNode LNode = new ExpTreeNode(); LNode._value = literal; LNode._ndType = ExpTreeNode.NodeType.Literal; NodeStack.Push(LNode); break; case Token.Operator: //pop the St ExpTreeNode ONode = new ExpTreeNode(); ONode._value = Curr_op; ONode._ndType = ExpTreeNode.NodeType.Operator; if(Curr_op == "(") { OpStack.Push(ONode); break; } if(Curr_op == ")") { while("(" != (string)OpStack.Top._value) { PopConnectPush(); } OpStack.Pop() ; //Throw away {{ break; } if(OpStack.IsEmpty()) { OpStack.Push(ONode); } else if((string)OpStack.Top._value == "(") { OpStack.Push(ONode); } else if(Priority(OpStack.Top._value.ToString()) < Priority(ONode._value.ToString() )) { OpStack.Push(ONode); } else { while(true) { PopConnectPush(); if(OpStack.IsEmpty() == true || (string)OpStack.Top._value == "(" || Priority(OpStack.Top._value.ToString() ) < Priority(ONode._value.ToString() )) break; } OpStack.Push(ONode); } break; case Token.Symbol: { ExpTreeNode SNode = new ExpTreeNode(); SNode._symbol = symbol; SNode._ndType = ExpTreeNode.NodeType.Symbol; NodeStack.Push(SNode); } break; default: break; } }while(NextToken() != Token.Eof); while(OpStack.IsEmpty() == false) { PopConnectPush(); } //Get the Top of the Node Stack thats the root return NodeStack.Top; }
//Not Implemented public string ReMakeExpression(ExpTreeNode Tree) { //Doing nothing right now return(""); }
public void Push(ExpTreeNode f) { data[top++] = f; }
public TreeStack(int size) { data = new ExpTreeNode[size]; top = 0; }
//Parse Expression funtion main funtion //Creating the Exp tree from the Infix Expression public ExpTreeNode ParseExpression(string exp) { //Check for the Expresiioon validity if (!Isvalid_Exp(exp)) { //Throw an Error Saying Commas are not proper ErrorException Er = new ErrorException("Operators ( or ) are not at the right places"); throw Er; //Is c# need this return after that -- i dont think so but anyway } //Fill ur _exp Variable will need that _exp = exp; NextToken(); do { //The errors that might come would be from stack //If that went wrong -- gone case -- What use rwould do //No USer specific Errors from this funtion switch (current) { case Token.Literal: //CreateLeafNode and push it on the stack ExpTreeNode LNode = new ExpTreeNode(); LNode._value = literal; LNode._ndType = ExpTreeNode.NodeType.Literal; NodeStack.Push(LNode); break; case Token.Operator: //pop the St ExpTreeNode ONode = new ExpTreeNode(); ONode._value = Curr_op; ONode._ndType = ExpTreeNode.NodeType.Operator; if (Curr_op == "(") { OpStack.Push(ONode); break; } if (Curr_op == ")") { while ("(" != (string)OpStack.Top._value) { PopConnectPush(); } OpStack.Pop(); //Throw away {{ break; } if (OpStack.IsEmpty()) { OpStack.Push(ONode); } else if ((string)OpStack.Top._value == "(") { OpStack.Push(ONode); } else if (Priority(OpStack.Top._value.ToString()) < Priority(ONode._value.ToString())) { OpStack.Push(ONode); } else { while (true) { PopConnectPush(); if (OpStack.IsEmpty() == true || (string)OpStack.Top._value == "(" || Priority(OpStack.Top._value.ToString()) < Priority(ONode._value.ToString())) { break; } } OpStack.Push(ONode); } break; case Token.Symbol: { ExpTreeNode SNode = new ExpTreeNode(); SNode._symbol = symbol; SNode._ndType = ExpTreeNode.NodeType.Symbol; NodeStack.Push(SNode); } break; default: break; } }while(NextToken() != Token.Eof); while (OpStack.IsEmpty() == false) { PopConnectPush(); } //Get the Top of the Node Stack thats the root return(NodeStack.Top); }