Re: from: Lua Module Function Critiqued

[Petite Abeille <petite.abeille@...>]

On Oct 9, 2013, at 8:50 AM, steve donovan <steve.j.donovan@gmail.com> wrote:

> The 5.2 compat module is indeed too simplistic - I found this out when
> trying to pack multiple modules into a single Lua file.

(Deprecating 'module' was rather uncharacteristically shortsighted. Oh, well…)

Now that we are all back busily reinventing that particular wheel with different level of squareness… here is my take:

do 
  local _ENV = module( 'foo' )
  … foo stuff ...
end 

do 
  local _ENV = module( 'bar' )
  … bar stuff ...
end 

do 
  local _ENV = module( 'baz' )
  … baz stuff ...
end 

In other words, each module is defined in a chunk (do… end), with its own _ENV. And that's that. The net effect is the same as 5.1 'module' in term of functionalities. 

'module' itself is implemented as follow:

do --8<--

--------------------------------------------------------------------------------
-- Import
--------------------------------------------------------------------------------

local assert = assert
local select = select
local type = type

local package = require( 'package' )

--------------------------------------------------------------------------------
-- Module
--------------------------------------------------------------------------------

local _ENV = {}

_VERSION = '1.0.0'

--------------------------------------------------------------------------------
-- Utilities
--------------------------------------------------------------------------------

local function module( aName, ... )
  local aModule = package.loaded[ assert( aName ) ]

  if type( aModule ) ~= 'table' then
    aModule = {}
    aModule._M = aModule
    aModule._NAME = aName
    aModule._PACKAGE = aName:sub( 1, aName:len() - ( aName:reverse():find( '.', 1, true ) or 0 ) )

    package.loaded[ aName ] = aModule

    for anIndex = 1, select( '#', ... ) do
      select( anIndex, ... )( aModule )
    end
  end

  return aModule
end

--------------------------------------------------------------------------------
-- Main
--------------------------------------------------------------------------------

package.loaded.module = module

end -->8--

Sigh...