//----------------------------------------------------------------------
//  SPECIFICATION FILE (cqueue.h)
//  This module exports an ADT for a queue of characters.
//----------------------------------------------------------------------
#ifndef cqueue_h
#define cqueue_h 1
#include "bool.h"

const int QMAX_LENG = 101;

class CharQueue {
    // ABSTRACTLY: a sequence of char values

public:
    Boolean IsEmpty() const;
        // POST: FCTVAL == (sequence is empty)

    Boolean IsFull() const;
        // POST: FCTVAL == true if no more
        // items can be stored, false otherwise

    void Enqueue( char newItem );
        // PRE: the sequence isn't full
        // MODIFIES: self
        // POST: newItem is the last in the
        // the sequence, others unchanged

    char Front() const;
        // PRE: the sequence isn't empty
        // POST: FCTVAL == first item in
        // the sequence

    void Dequeue();
        // PRE: the sequence isn't empty
        // MODIFIES: self
        // POST: the sequence is tail of
        // the sequence in self<entry>

    CharQueue();
       // MODIFIES: self
       // POST: the sequence is empty

#include "cqueue.pri"
};
#endif