Re: setfenv/getfenv

[steve donovan <steve.j.donovan@...>]

On Thu, Jan 14, 2010 at 6:49 AM, Nevin Flanagan <Alestane@comcast.net> wrote:
> function catch(valid, ...)
>        if valid then return ...
>        elseif expr1((...)) then
>                handler1
>        elseif expr2((...)) then
>                handler2
>        end
> end

There's a little gotcha if your protected blocks are in a function. Consider

doSomething()

and

doSomething()
return

Both will return nil, but the second clearly wants to return from the
enclosing function; the first does not.

Metalua does try..except, but it's a compiler so it knows if there are
return statements in the block.  Tricky to infer it at runtime!

steve d.