Re: May Thy Closures Be Blessed

[Abigail-II]

Very nice. Big savings because of caching the calculation of stringified value (I get an 18% difference, not a 3%). Unfortunally, this technique can't be used if you are subclassing a class that doesn't coorperate - then you will to call refaddr in each method. That's slower (traditional method being 69% faster), but faster than what I showed before. I would have expected to be able to gain a little more by writing the methods like:

sub name {
    my $key = ${+shift};
    $name {$key} = shift if @_;
    $name {$key};
}

but that doesn't give me any gain (or loss).

Abigail

[adrianh]

I get an 18% difference, not a 3%

Hmm. I do seem to have been lucky with my initial runs. I'm seeing between 3-10% on my box, but nothing near 18%. How odd.

Unfortunally, this technique can't be used if you are subclassing a class that doesn't coorperate

True. Although for hash based objects you could just use one slot for the key and still get safety for all your other state hashes.

I would have expected to be able to gain a little more by writing the methods like ...

Good point. Can any internals expert explain why +shift is so slow?

[Abigail-II]

Although for hash based objects you could just use one slot for the key and still get safety for all your other state hashes.

True, but then you make yourself dependent on the implementation of the superclass. It opens the door to collisions, and you get a problem when the superclass changes its implementation (say, it starts to use restricted hashes).

Abigail