-- File:	BinaryFunction.cdl
-- Created:	Mon Jan 14 16:20:04 1991
-- Author:	Arnaud BOUZY
--		<adn@topsn3>
---Copyright:	 Matra Datavision 1991

class BinaryFunction from Expr

inherits BinaryExpression from Expr

    ---Purpose: Defines the use of a binary function in an expression 
    --          with given arguments.

uses GeneralFunction from Expr,
    AsciiString from TCollection,
    GeneralExpression from Expr,
    Array1OfNamedUnknown from Expr,
    Array1OfReal from TColStd,
    NamedUnknown from Expr

raises InvalidFunction from Expr, 
    NumericError from Standard,
    NotEvaluable from Expr

is

    Create(func : GeneralFunction; exp1,exp2 : GeneralExpression)
    ---Purpose: Creates <me> as <func> (<exp1>,<exp2>).
    --          Raises exception if <func> is not binary.
    returns mutable BinaryFunction
    raises InvalidFunction;

    Function(me)
    ---Purpose: Returns the function defining <me>.
    returns GeneralFunction;
    
    ShallowSimplified(me) 
    ---Purpose: Returns a GeneralExpression after a simplification 
    --          of the arguments of <me>.
    returns any GeneralExpression
    raises NumericError;

    Copy(me)
    ---Purpose: Returns a copy of <me> having the same unknowns and functions.
    returns mutable like me;
    
    IsIdentical(me; Other : GeneralExpression)
    ---Purpose: Tests if <me> and <Other> define the same expression.
    --          This method does not include any simplification before
    --          testing.
    returns Boolean;

    IsLinear(me)
    returns Boolean;

    Derivative(me; X : NamedUnknown)
    ---Purpose: Returns the derivative on <X> unknown of <me> 
    returns any GeneralExpression;

    Evaluate(me; vars : Array1OfNamedUnknown; vals : Array1OfReal)
    ---Purpose: Returns the value of <me> (as a Real) by 
    --          replacement of <vars> by <vals>.
    --          Raises NotEvaluable if <me> contains NamedUnknown not 
    --          in <vars> or NumericError if result cannot be computed.
    returns Real
    raises NotEvaluable,NumericError;

    String(me)
    ---Purpose: returns a string representing <me> in a readable way.
    returns AsciiString;

fields

    myFunction : GeneralFunction;

end BinaryFunction;