store.h

能对输入的语句进行分析

#if !defined STORE_H
#define STORE_H
//------------------------------------
//  store.h
//  (c) Bartosz Milewski, 1994
//------------------------------------

#include <cassert>

enum { stNotInit, stInit };

class SymbolTable;

class Store
{
public:
    Store (int size, SymbolTable & symTab);
    ~Store ()
    {
        delete []_cell;
        delete []_status;
    }
    bool IsInit (int id) const
    {
        return (id < _size && _status [id] != stNotInit);
    }
    double Value (int id) const
    {
        assert (IsInit (id));
        return _cell [id];
    }
    void SetValue (int id, double val)
    {
        if (id < _size)
        {
            _cell [id] = val;
            _status [id] = stInit;
        }
    }
private:
    int         _size;
    double *    _cell;
    unsigned char * _status;
};
#endif