Re: Is Lua stable? (Was: Strange Operators (Was: Why I leave Lua (Was: Re: [ANN] Lua 5.3.0 (work3) now available)))

[Eric Wing <ewmailing@...>]

On 7/10/14, Steven Degutis <sbdegutis@gmail.com> wrote:
> Hello again.
>
> As I mentioned in other posts, I've recently started embedding Lua
> into my Objective-C (OS X) applications. Besides my short stint trying
> to use and configure "awesome" (a window manager), this has been my
> first real in-depth usage of Lua.

> But a very small part of me is concerned that it will continue to grow
> in breaking ways, eventually adding a disproportionate amount of
> complexity simply for the sake of continuing to work on it when
> there's nothing left to work on.

You found my trigger switch. As somebody who wrote a full fledged
language bridge between Lua and Objective-C (LuaCocoa), I disagree
with your sentiment that the changes are for complexity sake.

In Cocoa, the main integer type is NSInteger/NSUInteger which is
64-bit under Apple's 64-bit architectures and caused a lot of pain
points for me for bridging, particularly when APIs use max int as a
sentinel value. In 5.1, I resorted to the LNUM patch and was kind of
stranded in 5.2. I am so happy that Lua 5.3 is getting integer
subtypes. This is a killer feature for me (that go well beyond just
LuaCocoa as I'm also in video games and performance matters).

In Lua 5.2, __pairs and __ipairs became accessible. I have been very
interested in bridging Lua's iterators with Obj-C's fast enumeration
feature. It never made sense to me why there was no metamethods for
these. Now that's fixed.

One thing I still would like to see is Lua's exception handling
(implementation detail) refactored in a way that allows me to more
easily change it so I can make it use Apple's Obj-C @try/@catch
exception mechanism without compiling all of Lua as Obj-C.
http://lua-users.org/lists/lua-l/2012-04/msg00722.html

Apple's exception system has really nice benefits on their platform
because it is zero-cost try and also unified with C++ exception
handling (but doesn't require you to compile anything as C++). And it
allows pcall to trap any exceptions thrown in a native framework.

In fact, it makes so much sense, I really think there should be a
default convenience implementation shipped in Lua that is on by
default when compiling for Mac or iOS.

But as it stands now, I have to figure out how to refactor a bunch of
things in Lua every time there is a new release. I'm tired of that
busy work.


Thanks,
Eric
-- 
Beginning iPhone Games Development
http://playcontrol.net/iphonegamebook/