Re: [ANN] Compat-5.2: a tiny Lua module providing some Lua-5.2-style APIs for Lua 5.1

[Philipp Janda <siffiejoe@...>]

Am 03.09.2013 22:09 schröbte Hisham:
> Hi,

Hi!

> Feedback, contributions, pull requests and criticism are welcome!

1) You do:

    local unavailable = function() error("compat52: Do not use this 
function. It is incompatible with Lua 5.2") end

    setfenv = unavailable
    getfenv = unavailable

This breaks code like

    ...
    if setfenv then
      setfenv( chunk, env )
    end
    ...

which, I think, is a common idiom for code targeted at both Lua 5.1 and 
5.2. See e.g. here[1] ...

  [1]:  http://comments.gmane.org/gmane.comp.lang.lua.general/99000

(It also breaks my preferred idiom (`if _VERSION == "Lua 5.1" ...`), but 
since I cache all my globals I can just load my modules before 
require'ing compat52.)

How about a warning on stderr that you can disable via an environment 
variable instead of the error?


2) `table.unpack` is still available as a global `unpack` in Lua 5.2 if 
`LUA_COMPAT_UNPACK` is defined.

> -- Hisham
> http://hisham.hm/

Philipp