Re: Utility functions to manage sets

[Javier Guerra Giraldez <javier@...>]

Duck wrote:
> In code in LuaSocket and COPAS, you can find a utility "set" class such 
> as this:
...snip...
> This code is very cool, and the "add at end" and "delete by removing the 
> last element and writing it over the one you want to get rid of" is 
> clearly more time efficient than just using set[value] = true to add and 
> set[value] = nil to delete items.

for sets, i usually do as you mention (set[value]=true/nil), and i guess 
it's far more efficient than the code you quote.

the only reason it's cleverly done like that is that LuaSocket's 
select() fuction expects an array of sockets to wait on; and such a set 
is faster (nicer) than creating the array from a table's keys each time.

--
Javier