in reply to How can I access object data in a user defined sort cmp function?

why do you need a custom function byvalue() ?

Even sorting the keys of a normal hash by value¹ can only be done by somehow tunneling the reference into byvalue() by closure/currying (like choroba showed) or by doing a (schwarzian?) transform of the hash into an array of key/value-tupels.

Both approaches look like overkill if you can do this straightforwardly:

my %h = %{$self->{hash_ref}}; my @keys = sort { $h{$a} <=> $h{$b} } keys %h;

Easy to read, easy to understand.

So why ?

DB<100> $self={ hash_ref=>{item1=>'value1',item2=>'value2'} } => { hash_ref => { item1 => "value1", item2 => "value2" } } DB<101> %h=%{$self->{hash_ref}} => ("item1", "value1", "item2", "value2") DB<103> @keys=sort {$h{$a}<=>$h{$b}} keys %h; => ("item1", "item2")

Cheers Rolf

PS: Je suis Charlie!

PS: downvoted for lack of indentation, I agree with the Guido comment.

¹) hint "Reduction to a simpler problem"!