Re: NIL in arith. and string op.

["Nodir Temirhodzhaev" <tnodir@...>]

Some tests:

-- Or
local a = {}
for i = 1, 5000 do
 for j = 1, 1000 do
    a[i] = (a[i] or 0) + j
 end
end
-- 15.89user 0.00system 0:15.89elapsed

-- Init.
local a = {}
for i = 1, 5000 do a[i] = 0 end
for i = 1, 5000 do
 for j = 1, 1000 do
    a[i] = a[i] + j
 end
end
-- 14.31user 0.01system 0:14.32elapsed

-- Edit luaV_tonumber:
--  lua_Number num = 0; ...
--  if ((ttisstring(obj) && luaO_str2d(svalue(obj), &num))
--   || ttisnil(obj)) { ...
local a = {}
for i = 1, 5000 do
 for j = 1, 1000 do
    a[i] = a[i] + j
 end
end
-- 14.32user 0.00system 0:14.31elapsed

Perhaps, better is initialize...