-- File:	GenRel.cdl
-- Created:	Tue Aug 18 11:32:35 1992
-- Author:	Arnaud BOUZY
--		<adn@bravox>
---Copyright:	 Matra Datavision 1992

class GenRel from ExprIntrp inherits Generator from ExprIntrp

	---Purpose: Implements an interpreter for equations or system 
	--          of equations made of expressions of package Expr.

uses GeneralRelation from Expr,
    AsciiString from TCollection

raises NoSuchObject

is

    Create
    ---Purpose: Creates an empty generator
    ---Level: Advanced
    returns mutable GenRel is private;

    Create( myclass ) returns GenRel;
    
    Process(me : mutable; str : AsciiString)
    ---Purpose: Processes given string.
    ---Level: Advanced 
    is static;

    IsDone(me)
    ---Purpose: Returns false if any syntax error has occurred during 
    --          process. 
    ---Level: Advanced 
    returns Boolean
    is static;
	    
    Relation(me)
    ---Purpose: Returns relation generated. Raises an exception if 
    --          IsDone answers false.
    ---Level: Advanced 
    returns mutable GeneralRelation
    raises NoSuchObject
    is static;
    
fields

    done : Boolean;
    myRelation : GeneralRelation;
    
end GenRel;