Sorry I didn't intend to criticize you
I didn't interpret it that way ;-)
I'm rather interested to realize different paradigms in Perl, maybe by extending the language.
For instance it would be interesting to see, how easy/clumsy it is to retrofit lazy evaluation into Perl.
With enough pertinacity, every language can be made to look like LISP :-D
--
Ronald Fischer <ynnor@mm.st>
| [reply]
[d/l] |
> For instance it would be interesting to see, how easy/clumsy it is to retrofit lazy evaluation into Perl.
E.g.you can tie an iterator to a variable.
I'm not fluent in Haskell, so gimme an example and I'll see what's possible.
> With enough pertinacity, every language can be made to look like LISP :-D
Well, unfortunately it's not trivial to realize LISPish macros in Perl 5, otherwise most language extensions I can think of would be easily possible.
Compare Re^2: Dumping variables but DRY and simple for a use case for a macro.
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sub list_all_even {
_list_all_even_from(0)
}
sub _list_all_even_from {
my $from=shift;
($from, _list_all_even_from($from+2))
}
and a function which returns the first n elements from a list:
sub head {
my ($n,@list)=@_;
$n ? ($list[0],head($n-1,butfirst(@list))) : ()
}
sub butfirst {
shift;
@_
}
Calling head(5,list_all_even) should return the first even numbers, but in the implementation I gave, list_all_even would, of course, loop forever. Under lazy evaluation, list_all_even would only produces those values which are actually needed, so maybe your general idea of using an operator would lead in the right direction...
--
Ronald Fischer <ynnor@mm.st>
| [reply]
[d/l]
[select] |