in reply to Re: List-to-Scalar Function?
in thread List-to-Scalar Function?

You can also implement reduce in native Perl: 
sub reduce (&@) {
  my $op = shift;
  no strict 'refs';
  my $pkg = caller;
  local *A = local *{"$pkg\::a"};
  $A  = shift;
  local *B = local *{"$pkg\::b"};
  foreach $B (@_) {
    $A = $op->();
  }
  $A;
}

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(Stolen shamelessly from here, with full permission of the author. :-)

UPDATE
D'oh. I should have read the source-code. They don't present that in the documentation... And I wrote it originally because someone (jcwren I think) was having trouble running my code at Re (tilly) 1: An exercise in "That's not the way I'd do it" (TNTWIDI) because List::Util wasn't compiling.

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Re: Re (tilly) 2: List-to-Scalar Function?
by merlyn (Sage) on May 09, 2001 at 03:55 UTC
    Somewhat similar to the pure-Perl implementation in List::Util itself... 
    use vars qw($a $b);

sub reduce (&@) {
  my $code = shift;
  
  return shift unless @_ > 1;
  
  my $caller = caller;
  local(*{$caller."::a"}) = \my $a;
  local(*{$caller."::b"}) = \my $b;
  
  $a = shift;
  foreach (@_) {
    $b = $_;
    $a = &{$code}();
  }

  $a;
}

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    Although if the XS compiles and loads, this code is not used.

    -- Randal L. Schwartz, Perl hacker

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[d/l]

In Section Meditations