Re: Mixing different versions of Lua

[Pierre-Yves Gérardy <pygy79@...>]

On Sat, Feb 26, 2011 at 18:15, Reuben Thomas <rrt@sc3d.org> wrote:
> [...]Looking at the changes to the
> language for 5.2, it looks as though it is easily possible to write
> scripts that work in both 5.1 and 5.2, and probably quite feasible to
> write scripts that work in 5.0-5.2. Hence, arguably, this macro has a
>
> purpose.

 

LPEG is forward compatible:

in lpeg.c :

-----------------------------

/*

** compatibility with Lua 5.2

*/

#if (LUA_VERSION_NUM == 502)

#undef lua_equal

#define lua_equal(L,idx1,idx2)  lua_compare(L,(idx1),(idx2),LUA_OPEQ)

#undef lua_getfenv

#define lua_getfenv lua_getuservalue

#undef lua_setfenv

#define lua_setfenv lua_setuservalue

#undef lua_objlen

#define lua_objlen lua_rawlen

#undef luaL_register

#define luaL_register(L,n,f) \

{ if ((n) == NULL) luaL_setfuncs(L,f,0); else luaL_newlib(L,f); }

#endif

-----------------------------

in re.lua:

-----------------------------

-- No more global accesses after this point

local version = _VERSION

if version == "Lua 5.2" then _ENV = nil end

-----------------------------

-- Pierre-Yves