librelist archives

Re: [mongrel2] Proposed Tweak to Tir and mongrel2-lua

From:

joshua simmons

Date:

2011-05-17 @ 23:52

Also, the __index stuff is completely unrelated to any changes. That's bog
standard Lua prototype OOP and has been like that since the beginning.

The only change I've made is instead of module implicitly creating a module
table and putting it in the global scope, we create the table inside the
module, and return it from the module block.

The module function worked by creating a table, then setting that table as
the environment for the current block. Especially when used with
package.seeall there are a range of non-trivial issues with this method.
Firstly it puts your module straight into global scope, which has the usual
problems, less obviously, when using package.seeall the said module table
has it's metatable __index set to global _G which means one can break out of
a sandbox. Because modules can have dependencies and they too are loaded
into the global scope, dependencies are hidden from the caller. The
conclusion was that it was causing more issues than it was worth, and
replacing one line of magic code with two lines of simple non-magic code is
a good move.

I will definitely do a tidy up pass on the whole code base though.

On Wed, May 18, 2011 at 8:55 AM, Zed A. Shaw <zedshaw@zedshaw.com> wrote:

> On Wed, May 18, 2011 at 08:31:29AM +1000, joshua simmons wrote:
> > Basically module is being removed from Lua, the changes required are
> trivial
> > 'local x = require 'abc' rather than require 'abc' (which is kinda how
> you
> > should be doing it anyway)
>
> Yeah it works, but (as I mentioned in IRC) making me do it manually is
> annoying.
>
> > Using meta was a throw back to my ol garry's mod days, and because it's
> the
> > module's metatable. Giving it the class name is much more sane though.
> >
> > I'll have a look into making it more readable in mongrel2-lua but I don't
> > really want to take it away entirely.
>
> Cool, yes take a look at how I'm doing it in Tir where I have two modes
> of making classes:
>
> 1. ClassName = {}  or ClassName = { blah = function }.  Those work for
> typical style classes.
> 2. A function that can be used to "mint" or generate classes like #1.
> When I find a pattern in a bunch of classes, I then wrap them up in a
> function that makes the class on the fly and returns it.  Then I use
> that after to mint a bunch of them.
>
> That is really all you need and it's easy to use.
>
> > Ah looks like I've been sitting on the proxymustdie branch which is why
> I'm
> > on a completely different page with the config stuff.
>
> Sweet, that explains it.
>
> --
> Zed A. Shaw
> http://zedshaw.com/
>