2015-11-07 17:52 GMT+02:00 Marco Atzori <marco.atzori.1983@gmail.com>:
Il 07/11/2015 16:46, Matthew Wild ha scritto:
If you have actual constraints, revealing them might allow people to
help you better. If you don't have any constraints and just want it to
perform well, then there are some really much simpler and more
efficient solutions than your implementation.
This code is part of a videogames addon, and is executed every frame refresh
(about every tenth of a second) for which using tables created in
continuation is a considerable waste of memory. If there are simpler
solutions, show them to me as well. I asked your help for this reason ;-)
[from original post]
gettok(text,-1,46,-3)
I cannot envisage why that argument '46' should be needed at all.
I would use a table created once and for all for each string.
local tok_meta = { __index = { gettok =
function(tbl,i,j)
local n=#tbl
j = j or i
if i and i<0 then i=n+i+1 end
if j and j<0 then j=n+j+1 end
return table.concat(tbl,tbl.sep,i,j) end }}
local tokens = function(str,sep)
local fields={sep=sep}
str:gsub(("[^%s]+"):format(sep),function(field)
fields[#fields+1]=field
end)
return setmetatable(fields,tok_meta)
end
local s = tokens( "apple.banana.cherry.grape.orange",".")
s:gettok(1)
apple
s:gettok(-2)
grape
s:gettok(2,4)
banana.cherry.grape
s:gettok(-3,-1)
cherry.grape.orange
