> apparently the delete function does return a list of keys it's deleted, so delete(@A{keys B}) does return the intersection of A and B ...

Good observation! I forgot about this.... so one gets the difference and the intersection with one operation, thats brilliant.

So a simple upgrade of delete with an extra switch to ignore undefs would give Perl a native primitive to handle set operations...

And I enjoyed your post too, I'm still meditating about how to make use of your approach...

> (Even though I am a failed mathematician, it does sting a little that you felt the need to give me a link to De Morgan's laws.)

The link wasn't meant for you, believe me. :)

I'm mathematician by training but not a native English speaker, so I need to elaborate my posts longer and stuff them with extra informations to avoid misunderstandings. (And the monastery is full of obsessed nitpickers...)

Cheers Rolf

In reply to Re^4: Using hashes for set operations... by LanX
in thread Using hashes for set operations... by LanX

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