Re: A tricky way to determine Lua version (updated)
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- Subject: Re: A tricky way to determine Lua version (updated)
- From: Andrew Gierth <andrew@...>
- Date: 2020年7月20日 23:38:00 +0100
>>>>> "Egor" == Egor Skriptunoff <egor.skriptunoff@gmail.com> writes:
Egor> local f, t = function()return function()end end, {nil,
Egor> [false] = {[-1/0] = 'Lua 5.1', [1/0] = 'Lua 5.4'},
Egor> [true] = {[-1/0] = 'Lua 5.2', [1/0] = 'Lua 5.3'},
Egor> [1] = 'LuaJIT'}
Egor> local version = t[1] or t[f()==f()][1/'-0']
How about,
local f, t = function()return function()end end, {nil, -1,
[false] = {[-1/0] = 'Lua 5.1', [1/0] = 'Lua 5.4'},
[true] = {[-1/0] = 'Lua 5.2', [1/0] = 'Lua 5.3'},
[1] = 'LuaJIT'}
print(t[1] or t[f()==f()][1/(t[2]*0)])
Not sure how reliably the t[2]*0 evaluates to -0 on 5.1/5.2, though. It
works on the few platforms I tried. (Using a constant -1 there doesn't
work.)
--
Andrew.