> This can be seen without benchmarking. The problem with variadic
> arguments is that every function call with them is O(n), where n is
> the number of arguments. Just the call, ignoring whatever the function
> does. [...]
This is true for non-variadic functions as well, as Lua has to prepare
the n arguments to the function. I think most calls in most languages
follow that rule. (Inline functions that do not use its parameters would
be a counter-example.)
-- Roberto
Is it in fact the case that variadic functions have additional overhead? That is, calling `fn(a, b, c)` would be cheaper if this was defined as `function fn(a, b, c)`, rather than `function fn(...)` ?
I know there's more to this question than it appears, since one must *do* something with the arguments, and `{...}` would have different overhead from e.g. `select(1, ...)` and so on.
I had the impression that variadics carry some amount of overhead, but never benchmarked it.
For the sake of argument, we could compare:
function subber(...)
return string.sub(...)
end
with:
function subber(str, start, finish)
return string.sub(str, start, finish)
end
cheers,
-Sam
