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// cursor.hh
#ifndef __CURSOR_HH
#define __CURSOR_HH
#include "link.hh"
template<class T> class List;
///
template<class T>
class Cursor
{
public:
Cursor( const List<T>& list, Link<T>* pointer = 0 );
/** this isn't true, actually, #list# surely isn't const, but I get
tired of the warning messages. */
Cursor( const Cursor<T>& cursor );
T& thing();
/// return current T
T& operator *() { return thing(); }
operator T() { return thing(); }
Cursor<T> operator =( const Cursor<T>& c );
/// make cursor with #no# items back
Cursor<T> operator -( int no) const;
/// make cursor with #no# items further
Cursor<T> operator +( int no) const;
int operator -(Cursor<T> op) const;
Cursor<T> operator -=(int);
Cursor<T> operator +=(int);
/// return current and move one down
Cursor<T> operator ++( int );
/// return current and move one up
Cursor<T> operator --( int );
/// point to link?
bool ok();
/// ++ items left?
bool forward();
/// -- items left?
bool backward();
/// put (copy) after me in List
void add( const T& thing );
/**
analogously to editor. ok() interpreted as at end
of line.
PRE: !ok, POST: added to bottom()
PRE: ok, POST: added after me
cursor points to same object, cursor.next() is newly added
object.
*/
/// put (copy) before me in List
void insert( const T& thing );
/**
analogously to editor. ok() interpreted as at begin of
line.
PRE: !ok, POST: add to top()
PRE: ok, POST: add before me
cursor points to same object, cursor.previous()
is newly inserted object.
*/
///
void backspace();
///
void del();
/// access the list this came from
const List<T>& list() const ;
Link<T>* pointer();
private:
List<T>& list_;
Link<T>* pointer_;
};
/**
add and insert extend the list
items are always stored as copies in List, but:
List<String> : copies of String stored
List<String*> : copies of String* stored!
the operations add and insert actually delegate the work to List class.
*/
/*
comparisons.
*/
#include "compare.hh"
template<class T>
inline int cursor_compare(Cursor<T> a,Cursor<T>b)
{
return b-a;
}
template_instantiate_compare(Cursor<T>, cursor_compare, template<class T>);
#include "pcursor.hh"
#include "list.hh"
#include "cursor.inl"
#endif // CURSOR_HH
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