Evaluator.h

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//* -*- mode:C++; tab-width:4; c-basic-offset:4; indent-tabs-mode:nil -*- */
//    Name:       src/base/Evaluator.h
//    Purpose:    Defines an class that can evaluate PNodes
//    Author:     Shane T. Mueller, Ph.D.
//    Copyright:  (c) 2003--2013 Shane T. Mueller <smueller@obereed.net>
//    License:    GPL 2
//
//
//   
//
//     This file is part of the PEBL project.
//
//    PEBL is free software; you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation; either version 2 of the License, or
//    (at your option) any later version.
//
//    PEBL is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with PEBL; if not, write to the Free Software
//    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
#ifndef __EVALUATOR_H__
#define __EVALUATOR_H__
 
 
 
 
#include <stack>
#include <list>
//#include "PNode.h"
#include "Variant.h"
 
#include "FunctionMap.h"
#include "../utility/PEBLPath.h"
#include "VariableMap.h"
#include "../utility/PError.h"
//#include "../devices/PEventLoop.h"
 
 
class PNode;
class OpNode;
class DataNode;
class Variant;
class FunctionMap;
class VariableMap;
class PEventLoop;
 
 
 
class Evaluator
{
public:
 
    Evaluator();
    Evaluator(Variant & stacktop, string scope);
    ~Evaluator();
  
    void CallFunction(const OpNode * node);
 
 
    //If Evaluate returns with true, continue; otherwise, exit.
    bool Evaluate(const PNode * node);
    bool Evaluate(const OpNode * node);
    bool Evaluate(const DataNode * node);
  
    void Push(const Variant & v);
    Variant Pop();
    const Variant & Peek() const;
 
    unsigned long int GetStackDepth(){return mStack.size();};
 
    PEventLoop * GetEventLoop(){return mEventLoop;};
 
    bool IsVariableName(Variant v);
 
    static FunctionMap mFunctionMap;
 
    static VariableMap gGlobalVariableMap;
    
    //Ditto with mEventLoop:
    static PEventLoop * mEventLoop;
 
    static PEBLPath gPath;
 
 
 
    static const  PNode * gEvalNode;
 
 
    static PCallStack gCallStack;
 
 
    
private:
 
    //This list keeps track of the call sequence 
    //of evaluators, so that when an error is found,
    //all the calls can be traced back.  It is a list
    //instead of a stack so that we can examine it easily.
 
 
 
    std::stack<Variant> mStack;
 
    unsigned int mStackMax;
 
    VariableMap mLocalVariableMap; 
    
    std::string mScope;
 
};
 
 
#endif