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- Subject: Re: SV: Deep Copy prototype
- From: Daniel Silverstone <dsilvers@...>
- Date: Thu, 8 May 2003 12:46:34 +0100
On Thu, May 08, 2003 at 08:40:54AM -0300, Luiz Henrique de Figueiredo wrote:
> >I'm not saying it's a bad thing that Lua is memory efficient; I am
> >merely trying to determine if this is something which will eat CPU in my
> >case.
> Like everything else in Lua, strings are kept in a hash table. They are
> only hashed once, when they cross the C/Lua boundary (eg, in lua_pushstring
> or internally when the VM concatenates strings). Once in Lua, no more string
> hashing is needed. Like I said, string comparison becomes pointer comparison
> and strings become as fast as any other value (all comparisons are in effect
> pointer comparisons, except for numbers, booleans, and nil).
Sounding good...
> The memory overhead for strings is simply its hash value, which is an int.
> The time overhead is deciding whether a string is already in the string table
> and, if not, to add it. This is as hash table and thus should be fast, as fast
> as (actually faster than) table lookup, on which everything in Lua is based.
Aah, I get it ;-)
I was hoping it'd be something cunning, and that is cunning ;-)
Sounds excellent.
Thank you for that clarification.
D.
--
Daniel Silverstone http://www.digital-scurf.org/
Hostmaster, Webmaster, and Chief Code Wibbler Digital-Scurf Unlimited
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You look tired.