Re: modules, require, magic

[Patrick Donnelly <batrick@...>]

On Wed, Oct 19, 2011 at 1:26 PM, Roberto Ierusalimschy
<roberto@inf.puc-rio.br> wrote:
>>
>> On Oct 19, 2011, at 5:32 PM, Roberto Ierusalimschy wrote:
>>
>> > If you really want 'module', wouldn't be simpler to use
>> >
>> > _ENV = module(...)
>> >
>> > with a simplified version of 'module'?
>>
>> By simplified, do you mean a 5.2 version not doing any of the setfenv() mambo jambo of the 5.1 implementation, but otherwise equivalent in functionality?
>>
>> With the environment switching as an explicit _ENV assignment?
>
> For instance (also without the global setting). Something like this:
>
> function module (name, ...)
>  local env = package.loaded[name]
>  if env == nil then
>    env = {}
>    package.loaded[name] = env
>  end
>  env.NAME = name
>  env.M = env
>  for _, f in ipairs{...} do
>    f(env)
>  end
>  return env
> end

[Assuming the above function were put in Lua 5.2,] package.seeall has
questionable usefulness even-more-so now that modules are not put in
the global environment. I would also second the syntactic sugar
addition of something like:

local abs, floor in require "math"

or similar. That way we can nicely document dependencies without
taking dozens of lines of code to do it.

-- 
- Patrick Donnelly