Re^2: elsif chain vs. dispatch

[ruzam]

in reply to Re: elsif chain vs. dispatch
in thread elsif chain vs. dispatch

$y could be passed as a reference to avoid the string copy further reduce the disadvantage, particularly for large strings.

my %dispatch=(
   A=>sub { split(/!/,$$_[0]); },
   ... 
); 

sub dispatch {
   my $x=$letters[random($nLetters)];
   my $y='xyzzy!' x random(1000);
   if (exists $dispatch{$x}) {
      $dispatch{$x}->(\$y);
   } else {
      warn "Huh?";
   } 
}

On the other hand, maybe the parameter string isn't copied when the function references $_[0] directly?

[almut]

I had tried that.  And had first made the same mistake (and thus got a speed boost of around 800% :) —> the $$_[0] would need to be ${$_[0]}. With that fixed, there's virtually no difference...   In other words, the string isn't copied, even without using references ($_[0] is an alias).

[ruzam]

Interesting. Now I've got some code to review that may stand for another tweak or two :)