-- File:	RelationIterator.cdl
-- Created:	Mon Jan 14 10:02:45 1991
-- Author:	Arnaud BOUZY
--		<adn@topsn3>
---Copyright:	 Matra Datavision 1991


class RelationIterator from Expr

	---Purpose: Iterates on every basic relation contained in
	--          a GeneralRelation.
        ---Level : Internal

uses GeneralRelation from Expr,
    SingleRelation from Expr,
    Array1OfSingleRelation from Expr

raises NoMoreObject from Standard,
    NoSuchObject from Standard

is

    Create(rel : GeneralRelation)
    returns RelationIterator;
    
    More(me)
    ---Purpose: Returns False if no other relation remains.
    returns Boolean
    is static;
    
    Next(me : in out)
    raises NoMoreObject
    is static;
    
    Value(me)
    ---Purpose: Returns current basic relation.
    --          Exception is raised if no more relation remains.
    returns  SingleRelation
    raises NoSuchObject
    is static;

fields

    myRelation : Array1OfSingleRelation;
    current : Integer;

end RelationIterator;