Re: A tricky way to determine Lua version

[Sean Conner <sean@...>]

It was thus said that the Great Ulrich Schmidt once stated:
> 
> Am 21.05.2016 um 09:13 schrieb Sean Conner:
> >It was thus said that the Great Vadim A. Misbakh-Soloviov once stated:
> >>>  Mine relies upon strings still having a metatable.
> >>But lacks luajit ;)
> >
> >  Nah.  If version is nil, it's LuaJIT.
> >
> >  -spc (nil can't be a table key, see ... )
> 
> Thats all true. I still like Egors version because it is simple to use.
> (without nil tests.) and the results can be changed eg.
> 
> function needs_setfenv()
>   local f, t = function() return function() end end, {nil,
>      [false]  = true,  --'5.1',
>      [true]   = false, --'5.2',
>      [1/'-0'] = false, --'5.3',
>      [1]      = true,  --'JIT'
>      }
>   return t[1] or t[1/0] or t[f()==f()];
> end;

  Hmm ... okay, how about:

local version = ({Q="Lua 5.1",R="Lua 5.2",S="Lua 5.3"})[
        ("").dump(function() end):sub(5,5)] or "LuaJIT"

And you can change it just as easily:

local version = ({Q=true,R=false,S=false})[
        ("").dump(function() end):sub(5,5)] or true

  -spc (Okay, so a few comments might be nice ... 8-)