use Perl

• The real way to write factorial in Perl 6: (Score:1)

  by Aristotle (5147)

  my $fac10 = [*] 1 .. 10;

  It isn’t even worth pulling out into a function.
  • Re: (Score:1)

    by cyocum (7706)

    Perl Golf still lives, I see. I had started playing around with subsets and had intended to update it with stuff like that but I will just say wow...that is really neat.
    • Re: (Score:1)

      by Aristotle (5147)

      It’s not golf! That’s just bog-standard Perl 6. Hyper- and reduce operators are normal part of the repertoire and in fact one of the reasons I am looking forward to v6. They get rid of huge swathes of monkey code… as you just saw. Lots of things that would require loops, which really constitute nothing but accidental complexity, can be expressed by a single operator.
      • Re:The real way to write factorial in Perl 6: (Score:1)

        by n1vux (1492) on 2008.12.08 19:28 (#66363) Homepage Journal

        This old APL/J and Prolog programmer agrees that Perl6 is my dream languoge, as it has hyper / reduce and grammars/structure-matching search, plus threads, though perhaps without the elegance of Hoare-Dijkstra parallel calculus as I originally envisaged (nor even the terseness of sh's & ).

        However, how will the simple [*] 1..$n work or fail when $n is large like 100 or 8.424000e+08 ? Does it magically transform to a generator and tail recursion under the covers, or does it do what it appears to say and fill memory with a low entropy sequence? Fills your swap disk and dies horribly is much worse than throwing floating overflow exception after 200 iterations.

        See http://www.perladvent.org/2008/3/ [perladvent.org] for benchmarks where it doesn't fail for absurd inputs so we can discuss them.

        --
        Bill
        # I had a sig when sigs were cool
        use Sig;

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        • Re: (Score:1)

          by Aristotle (5147)

          Perl 6 lets you write 1..* (or alternatively 1..Inf). That should answer your question. :-)