Since when dealing with code refs, there is no difference between not existing and undefined, I always prefer to write:

if ( exists $func{$sub} )
{
   $func{$sub}->($data)
}
else
{
   $func{one}->($data)
}
[download]

as:

($func{$sub} || $func{one})->( $data );
[download]

which at least ensures that the same parameters are passed to (and possibly returned from ) the default routine. More compact and fewer things to worry about from a maintenance point of view!

Liz