Re: package.path doesn't contain './?/init.lua'

[Geoff Leyland <geoff_leyland@...>]

On 28/04/2009, at 1:09 PM, David Manura wrote:

> On Mon, Apr 27, 2009 at 4:15 PM, Geoff Leyland wrote:
> > The default package.path contains './?.lua', but not './?/init.lua'.
> >  Obviously, it's easy to add, so there's no problem, but I often  
> > find myself
> > adding it.  Any reason it's not there by default?
>
> Perhaps we should instead ask why init.lua it not eliminated entirely.
> It is not necessary[1], and I think it complicates things[2].  Module
> authors need to decide which form to use, and it's near certain that
> different module authors will choose different conventions.  Module
> users or Lua distributions, when adding a directory to the Lua search
> path, may need to add both forms in general, though omitting the
> latter might usually work or might appear to initially work.  It also
> opens the ambiguity where ".../a/init.lua" could represent the module
> "a" or a module actually named "a.init".  Finally, it makes module
> search errors longer for the end-user:

While we're discussing packages, what's the logic behind the  
difference between what's returned by require and what's put in _G?

mod.lua:
module(...)
a = 1
return 3

> print(require("mod"))
2
> print(type(mod))
table

This may seem irrelevant, but I often put a single class or function  
into a file:

obj.lua:
local setmetable = setmetatable
module(...)
obj = {}
function obj:new()
  self.__index = self
  return setmetatable({}, self)
end

and create a new obj I have to go:

> require("obj")
> o = obj.obj:new()

which is a bit awkward.

An alternative is to put a "return obj" at the end of obj.lua, and  
then I need to go
> local obj = require("obj")
> o = obj:new()

Where I have to add the "local obj ="

One workaround is:

obj.lua:
local setmetable = setmetatable
module(...)
function new(self)
  self.__index = self
  return setmetatable({}, self)
end

> require("obj")
> o = obj:new()

But I kind of get the feeling I'm not Doing The Right Thing in all  
these cases.  I don't have any solution to this, or any strong  
opinions, just wondering if anyone has a better idea.

Cheers,
Geoff