containerpresentation.h

用于词法分析的词法分析器

/*
  $Id: ContainerPresentation.h,v 1.2 1997/02/02 01:31:05 matt Exp $
  
  Container presentation class.
  
  (c) Mat 95 Matt Phillips.
  */

#ifndef _CONTPRES_H
#define _CONTPRES_H

#include <iostream.h>

#include "ContainerIter.h"
#include "Data.h"

template <class T>
class ContainerPresentation
{
public:
   
  virtual ~ContainerPresentation () {}
   
  // class name
  virtual const char *name () const {return "ContainerPresentation";}
  // number of items
  virtual int nItems () const = 0;
  // is empty
  int isEmpty () const {return nItems () == 0;}
  // is full (default is never full)
  virtual int isFull () const {return 0;}
  // clear container
  virtual void clear () = 0;
  // iterator
  virtual ContainerIter<T> *makeIter () const = 0;
  // print
  virtual void printTo (ostream &s) const;
};

template <class T>
void ContainerPresentation<T>::printTo (ostream &s) const
{
  ContainerIter<T> *i;
   
  for (i = makeIter (); *i; (*i)++)
    s << i->ref () << endl;
   
  delete i;
}

template <class T>
ostream &operator << (ostream &s,
		      const ContainerPresentation<T> &c)
{
  c.printTo (s);
  return s;
}

#ifdef __BCC__

// the below is necessary for Borland C++ 4.0, something to do with
// its nonstandard (I think) ostream_withassign class
template <class T>
ostream &operator << (ostream_withassign &s,
		      const ContainerPresentation<T> &c)
{
  c.printTo (s);
  return s;
}

#endif

#endif