Function.h

#ifndef FUNCTION_H
#define FUNCTION_H
#include "Record.h"
#include "ParseTree.h"

#define MAX_DEPTH 100


enum ArithOp {PushInt, PushDouble, ToDouble, ToDouble2Down,
	IntUnaryMinus, IntMinus, IntPlus, IntDivide, IntMultiply,
	DblUnaryMinus, DblMinus, DblPlus, DblDivide, DblMultiply};

struct Arithmatic {
	ArithOp myOp;
	int recInput;
	void *litInput;
Arithmatic() : myOp(ToDouble2Down), recInput(-1), litInput(0) {}
};

class Function {

private:

	Arithmatic *opList;
	int numOps;

	int returnsInt;

public:

	Function ();
        ~Function () {
          for (int i = 0; i < numOps; i++)
            {
              if (-1 == opList[i].recInput) // check for literal values and free them.
                {
                  if (PushInt == opList[i].myOp)
                    {
                      delete (int *) opList[i].litInput;
                    }
                  else if (PushDouble == opList[i].myOp)
                    {
                      delete (double *)opList[i].litInput;
                    }
                }
            }
          delete[] opList;
        };
	// this grows the specified function from a parse tree and converts
	// it into an accumulator-based computation over the attributes in
	// a record with the given schema; the record "literal" is produced
	// by the GrowFromParseTree method
	void GrowFromParseTree (struct FuncOperator *parseTree, Schema &mySchema);

	// helper function
	Type RecursivelyBuild (struct FuncOperator *parseTree, Schema &mySchema);

	// prints out the function to the screen
	void Print ();

	// applies the function to the given record and returns the result
	Type Apply (Record &toMe, int &intResult, double &doubleResult) __attribute__ ((hot));
};
#endif