Well, with Data::Flow, which I maintain, you
use rules (or as Ilya calls them, recipies), to define,
how hash keys are generated.
in reply to Rules-based Perl?
One important thing I would like to see out of any such efforts
in Perl is that the rules should be invertable. For example,
if you go through a series of steps to turn input into output,
then given the output, you should be able to chain backwards
and re-generate the input.
The language currently compiling on my macosx ibook right now
is the language used to place 4th in the International
Conference on Functional Programming Contest. It is both
logical and functional and is called
It has a short tutorial and I think you will find it's
description appealing. Both first and second place were
taken by CAML (from inria.fr --- I lost interest in this
langauge when I saw it was not purely functional or logical
but also contained imperative elements.) And 3rd place was
taken by a team working in
a purely functional language.
Also, Perl 6 is planned to have additional functional
capability. And finally, what you have above is known as
an Agenda design pattern and was described in the article
"Design Patterns" in The Perl Journal a few issues before
it's first crucifixion (TPJ will rise from the dead right?!)