-- File:	RUIterator.cdl
-- Created:	Wed Feb  6 16:39:20 1991
-- Author:	Arnaud BOUZY
--		<adn@topsn3>
---Copyright:	 Matra Datavision 1991


class RUIterator from Expr

	---Purpose: Iterates on NamedUnknowns in a GeneralRelation. 
    	---Level : Internal

uses GeneralRelation from Expr,
    NamedUnknown from Expr,
    MapOfNamedUnknown from Expr
    
raises NoMoreObject from Standard,
    NoSuchObject from Standard

is

    Create(rel : GeneralRelation)
    ---Purpose: Creates an iterator on every NamedUnknown contained in 
    --          <rel>.
    returns RUIterator;
    
    More(me)
    ---Purpose: Returns False if on other unknown remains.
    returns Boolean
    is static;
    
    Next(me : in out)
    raises NoMoreObject
    is static;
    
    Value(me)
    ---Purpose: Returns current NamedUnknown.
    --          Raises exception if no more unknowns remain.
    returns NamedUnknown
    raises NoSuchObject
    is static;

fields

    myMap : MapOfNamedUnknown;
    myCurrent : Integer;

end RUIterator;