Re: Shorthand for appending to a table (was Re: 5.2 feature list?)

[Javier Guerra <javier@...>]

On Monday 11 September 2006 1:03 pm, Tim Gogolin wrote:
> Right; I understand this point of view.  The problem though is that
> table.insert(t, v ) has a hash lookup penalty and a function call
> penalty.
>
> local table_insert = table.insert
>
> will get rid of the hash lookup, but the function call is somewhat
> painful inside a tight loop.

on my machine (2.4Ghz P4, 512KB, kubuntu Dapper, lua5.1):

time lua -e 'local t={} for i = 1,1e7 do t[#t+1]=1 end'
real    0m4.730s
user    0m4.136s
sys     0m0.480s

time lua -e 'local t={} local tinsert=table.insert for i = 1,1e7 do tinsert 
(t,1) end'
real    0m5.884s
user    0m5.100s
sys     0m0.476s

less than 25% difference... not significant

-- 
Javier

Attachment: pgpgH2fFCXBwF.pgp
Description: PGP signature