-- File:	SelectUnion.cdl
-- Created:	Mon Jan 11 12:34:05 1993
-- Author:	Christian CAILLET
--		<cky@sdsun1>
---Copyright:	 Matra Datavision 1993


class SelectUnion  from IFSelect  inherits SelectCombine

    ---Purpose : A SelectUnion cumulates the Entities issued from several other
    --           Selections (union of results : "OR" operator)

uses AsciiString from TCollection, EntityIterator, Graph

is

    Create returns mutable SelectUnion;
    ---Purpose : Creates an empty SelectUnion

    RootResult (me; G : Graph) returns EntityIterator;
    ---Purpose : Returns the list of selected Entities, which is the addition
    --           result from all input selections. Uniqueness is guaranteed.

    Label (me) returns AsciiString from TCollection;
    ---Purpose : Returns a text defining the criterium : "Union (OR)"

end SelectUnion;