Re: How can I learn about Object Oriented programming with lua?

[Steve Litt <slitt@...>]

On Thu, 27 Feb 2014 07:50:57 +0200
steve donovan <steve.j.donovan@gmail.com> wrote:

> On Thu, Feb 27, 2014 at 1:57 AM, Sean Conner <sean@conman.org> wrote:
> > You can also write Lua in a functional style (you don't get lazy
> > evaluation, but neither do you have multiple inherentance), which I
> > feel is worth looking into.
> 
> Absolutely, and Javier would endorse this as well, I think. The
> mindblowingly powerful concept of "closures" = functions + bound state
> makes a lot of those awkward patterns very straightforward.

Hi Steve,

I must be missing something here, because I never thought of closures
as mindblowingly powerful. First, maybe I have the wrong idea of what a
closure is. I thought it was an inner function contained in an outer
function, where the inner function is passed back as the return of the
outer function, and the inner function can see and modify the outer
function's local variables, but each newly returned inner function
starts over with the vars set by the outer function, so four returned
inner functions can operate completely independently of each other. Am
I right so far?

If so, I don't see anything closures can do that
Perl/Python/Ruby/C++/Java objects can't do, with the outer function's
local vars being replaced by object data elements. Or, for that matter,
a C struct where some of the struct's elements are data and others
are function pointers, with a C macro to add OOP syntactic sugar.

Don't get me wrong: I love closures because in Lua, they're one tool
that's useful for a huge number of situations, but I've missed how
they're more powerful than standard objects or ordinary callback
routines.

Thanks,

SteveT

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