FWIW

I once implemented a ( Monad style ;-) approach to emulate this

 @results = take { [$a,$b,$c] if $a**2 +$b**2 ==$c**2 } from {1..30} $a from {1..$a} $b from {1...$b} $c

take(&$) and from(&$$) where just ordinary functions passing iterators around.

The problem I couldn't solve was a DRY scoping of the variables, to be strict I needed to surround the whole expression with

{ 
  my($a,$b,$c);
  ...
}

[download]

my declarations don't effect the scope of the same line. :(

Cheers Rolf

(addicted to the Perl Programming Language and ☆☆☆☆ :)

update

hmm maybe this syntax is acceptable?

from { 1..30} my $a from {1..$a} my $b from { 1...$b} my $c;
@results = take { [$a,$b,$c] if $a**2 +$b**2 ==$c**2 }

[download]

when called from void context from() could put the iterator into $_ , and take() could read it again from $_ if called with just one block arg...

never mind doesn't work.

In reply to Re^5: Concise foreach expression by LanX
in thread Concise foreach expression by ram31

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.