//----------------------------------------------------------------------
//  SPECIFICATION FILE (clist.h)
//  This module exports a class for maintaining lists of
//  single characters
//----------------------------------------------------------------------
#ifndef clist_h
#define clist_h 1

#include "bool.h"

const int LMAX_LENG = 100;

class CharList {

    // ABSTRACTLY: a ordered sequence of values
    // and a cursor, which is a position in the list or 1 beyond the tail end

    // CLASSINV: the sequence is empty --> the cursor is beyond the tail end

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 Reset();
        // PRE: the sequence is not empty
        // MODIFIES: self
        // POST: the cursor is at the front

    Boolean EndOfList() const;
        // POST: FCTVAL == (list cursor is beyond end of list)

    void Advance();
        // PRE: the cursor is not beyond end
        // MODIFIES: self
        // POST: cursor points to next item

    char CurrentItem() const;
        // PRE: cursor is not beyond end
        // POST: FCTVAL == item at cursor

    void InsertBefore( char someChar );
        // PRE: another item can be stored
        // MODIFIES: self
        // POST: self has someChar at cursor
        // && someChar precedes the item at cursor<entry> (if it exists)

    void InsertAfter( char someChar );
        // PRE: another item can be stored
        // MODIFIES: self
        // POST: self has someChar at cursor 
        // && someChar follows the item at cursor<entry> (if it exists)

    void Delete();
        // PRE: cursor is not beyond end
        // MODIFIES: self
        // POST: item at cursor<entry> is not in the sequence
        // && cursor at next item (if it exists)

    CharList();
        // MODIFIES: self
        // POST: sequence of values is empty
#include "clist.pri"
};
#endif