Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid

Re^2: elsif chain vs. dispatch

by ruzam (Curate)
on Apr 27, 2009 at 02:40 UTC ( #760239=note: print w/ replies, xml ) Need Help??

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?

Comment on Re^2: elsif chain vs. dispatch
Download Code
Replies are listed 'Best First'.
Re^3: elsif chain vs. dispatch
by almut (Canon) on Apr 27, 2009 at 02:53 UTC

    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).

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

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://760239]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others perusing the Monastery: (3)
As of 2015-11-26 21:07 GMT
Find Nodes?
    Voting Booth?

    What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

    Results (707 votes), past polls