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Content-type: text/plain
Robert,
Thanks for your note. But someone please help me understand this.
I proposed to define the function
TYPE
Function* = POINTER TO ABSTRACT RECORD END;
PROCEDURE (f: Function) ValueOf* (x: REAL): REAL, NEW, ABSTRACT;
and use it as
TYPE
MyFunction = POINTER TO RECORD (NumericalProcessor.Function) END;
I am trying to understand why this is so different from procedure
types. The above literally defines a procedure type and allows
you to pass a procedure as a parameter.
(1) Is the problem one of requiring all the math functions in the
library
to be this type if you are going to be able to pass them as parameters?
Would it be a major complication to have to wrap the functions this way?
(2) Is it a convenience problem of having to write
f.ValueOf (min)
instead of
f (min)
I can understand your point if the answer is yes to either of these
questions, although it seems that (1) would be the most problematic.
Are these two points why you say that procedure types are simple
and direct? Or are there some other complications?
Thanks for everybody's feedback.
Cheers,
Stan
>>> Stan:
>>>
>
>>>> With object-orientation, procedure types are redundant and should
>>>> be eliminated, IMHO. You should design your numerical processing ...
>
>>> I do not disagree with your example, but who would ever use this
>>> approach?
>>> Your book on OOP is not among those that define numerical analysis.
>>> "Numerical Recipes" are the foundation. It goes back to Fortran-IV.
>>> If
>>> anyone wants to calculate some integral or a special function, they
>>> will
>>> read Press & Teukolsky, not S.Warford.
>
>>> Along the lines of realism: one of our treasures is the
>
>>> huge collection of
>>> numerical software published and maintained by R.Campbell.
>
>>> Please keep the
>>> compiler compatible with his collection, not the other way around.
>>>
>
>>> Wojtek
>
> By one of those ironies that make life interesting
> Wojtek has chosen a bad example. In my Subsystem Lib
> almost all the numerical stuff is procedural EXCEPT
> the integrators and root finders.
>
> In contrast ALL the mathematical stuff in Subsystem Algebra
> is o-o.
>
> However I firmly believe that procedure type are sometimes the
> simple and direct solution to a problem and should be kept.
> Just ignore people who call them obsolete, they are not.
>
> This reminds me of discussions about the merits of recursion
> verses iteration. Some problems require recursion, most in my
> area of work are simpler with iteration. I would not want
> to work in an environment (FORTRAN IV or Lisp) that mandated one
> or the other.
>
> Robert
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Received on Thu Nov 18 2004 - 17:23:04 UTC