On 10/4/05, Oliver Bandel <oliver@first.in-berlin.de> wrote:
> Hello,
>
> is there a general overvie (paper or book), where
> functional and imperative approaches to solve a problem are
> compared directly?
>
> Most often people say, imperative is faster in most of all
> cases, and only in some cases FP might be faster.
>
> If there is a paper/book about problem solving and performance,
> comparing different approaches I would be happy to have a pointer
> to it.
>
> Also it would be nice to find something about how
> classical imperative style, OO-style and FP-style
> are solving problems, and which patterns can be done
> easier in the one or the other way.
>
> I recently had a discussion about some OO-patterns
> ( so called "GoF"-Book) and tried to solve some of them with
> OCamls module system.
> Adapter and bridge was talked about. Adapter was easy in writing a simple
> wrapper.
> Bridge could be done with a functor. :)
>
> So, if there are direct translations possible, where to find
> comparisons?
>
> Another interesting theme in this respect is: If not only some patterns
> were adapted to Fp, but the whole problem solving approach is different,
> which patterns will be unnevcessary then, because the whole structure of
> the software will be different...?!
>
> Ciao,
>   Oliver

Sigh, your question only begs for trolls to pop out of the corners.

It would probably be best to keep these questions off this list. Far
too often they go off into the deep end of the 'my language is better
than your language' debates. Obviously members of this list are going
to be biased towards functional languages and will probably give you
biased articles to read or biased papers. Not necessarily biased in a
bad way, just more likely to show functional languages in a good
light.

A poor place to start reading on the subject of what language is best
is The Computer Language Shootout [1]. An even worse place to start
reading is this list.

The actual performance for any program will depend largely on your
ability to program well for the language and for the specific compiler
you choose.

I would say it's obvious that some patterns are easier to *write* in a
certain language, but that hardly shows which language is *best* speed
wise. Your example shows one pattern functional languages are well
suited for, however, I'm sure an experienced C programmer could show
you an example of that pattern which is both efficient and easy to
read (I know I know people on this list may disagree).

This list is best for asking OCaml questions and is awful for asking
for what language is best for what, nobody agrees.

--
Christopher A. Watford
christopher.watford@gmail.com

[1] http://shootout.alioth.debian.org/