in reply to Re: How does map work?
in thread [Solved] How does map work?

thanks for the assist. Indeed my use of while was incorrect

Indeed HOP does doe a version of map that takes an iterator, and I'm sure it will just take plugging away at HOP some more, it starts to make sense after a few read throughs...

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Re^3: How does map work?
by LanX (Saint) on Oct 26, 2013 at 21:57 UTC
    Hmm seems like HOP doesn't show how to reimplement plain map.

    But as a side note, perlsub has an example for grep :

          And here’s a reimplementation of the Perl "grep" operator:

           sub mygrep (&@) {
               my $code = shift;
               my @result;
               foreach $_ (@_) {
                   push(@result, $_) if &$code;
               }
               @result;
           }

    [download]

    HTH!

    Cheers Rolf

    ( addicted to the Perl Programming Language)

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Re^3: How does map work?
by muba (Priest) on Oct 28, 2013 at 18:31 UTC

    There is one instance where while sets $_ (or at the very least has the appearance to do so), and that's in the special while( <$filehandle> ) {...} construction (or ... while <$filehandle> for that matter, I believe).

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