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- Subject: Re: absence of a __hash metamethod
- From: Miles Bader <miles@...>
- Date: Fri, 16 Nov 2007 09:05:48 +0900
Colin <email@example.com> writes:
> I would guess that one of the reasons of the missing __hash meta event is
> that it's not that easy to design -- how do you make sure that the __hash
> meta event is "compatible" with the Lua hash function and the other table
Not to mention a non-negligible speed hit in a rather critical area of
Lua! Making table lookups slower makes _everything_ slower.
It would probably be much more acceptable if user-defined __hash hooks
were only used for tables with some flag turned on (which could be
tested very quickly in the C core), with that flag defaulting to off.
The car has become... an article of dress without which we feel uncertain,
unclad, and incomplete. [Marshall McLuhan, Understanding Media, 1964]