Re: [Mathlib-develop] Path Function & problems with funcion calls

[mark <msp...@ya...>]

On Thursday 20 Feb 2003 7:40 pm, Stefan Mueller wrote:
> > While testing it I notived a problem with function calls
> >
> > entering
> >
> >>path
> >
> > runs the path function and sets the ans variable but doesn't display
> > anything
> >
> > while entering
> >
> >>path()
> >
> > displays the result of the function call.
>
> I'll have a look into it.
>
> Kind regards,
>    Stefan.


This seems to be connected to the function being treated as a variable ra=
ther=20
than a function when the brackets are ommitted.

There is a similar problem if there is a space between the function name =
and=20
the brackets. If you enter
>sin (5)

then you get a null pointer error.

After checking it seems that MathLib treats VariableTokens and FunctionTo=
kens=20
in the same way. It first checks for a variable with that name then for a=
=20
function.

Therefore it might be an idea to combine VariableTokens and FunctionToken=
s=20
into one class (Say ReferenceToken) since this would ensure consistent=20
behaviour regardless of how the function or variable is entered.

One difficulty is the fact that VariableToken descends from OperandToken =
while =20
FunctionToken descends from OperatorToken. RefereenceToken would have to =
be a=20
subclass of OperandToken which would mean that it would have to store any=
=20
parameters being passed to the variable or function.

Though this would have the advantage of making functions more consistent =
with=20
keyword functions such as IF and WHILE.

Best Regards

Mark