-- File:	GenExp.cdl
-- Created:	Thu Jul 18 18:13:12 1991
-- Author:	Arnaud BOUZY
--		<adn@topsn2>
---Copyright:	 Matra Datavision 1991


class GenExp from ExprIntrp inherits Generator from ExprIntrp

	---Purpose: This class permits, from a string, to create any 
	--          kind of expression of package Expr by using 
	--          built-in functions such as Sin,Cos, etc, and by 
	--          creating variables.

uses GeneralExpression from Expr,
    AsciiString from TCollection

raises NoSuchObject

is

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

    Create( myclass ) returns GenExp;
    
    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;
	    
    Expression(me)
    ---Purpose: Returns expression generated. Raises an exception if 
    --          IsDone answers false.
    ---Level: Advanced 
    returns any GeneralExpression
    raises NoSuchObject
    is static;
    
fields

    done : Boolean;
    myExpression : GeneralExpression;
    
end GenExp;