Re: stack level parameter
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- Subject: Re: stack level parameter
- From: steve donovan <steve.j.donovan@...>
- Date: 2010年1月22日 09:32:13 +0200
On Fri, Jan 22, 2010 at 9:20 AM, M Joonas Pihlaja
<jpihlaja@cc.helsinki.fi> wrote:
> I suppose you'll need debug.getfenv() for that, no? If you need to
> keep track of the current env yourself explicitly (say by
> side-effecting some state which you need to undo) then I'm not sure
> how it would work.
Yes. Have a look at this:
function global(env)
local outer = _G --> !
return setmetatable({},{
__index = function(tab, key)
if env[key] ~= nil then return env[key] end -- look in our environment
if outer[key] ~= nil then return outer[key] end -- if not, look
in enclosing environment
return nil
end;
__newindex = function(tab, key, val)
env[key] = val
end
})
end
t = {}
in global(t) do
x = 10
y = x*x
z = math.max(10,y)
end
print(t.x,t.y,t.z)
Works as expected if we just want global access. But the temptation to
use getfenv(1) otherwise is pretty strong ;)
steve d.
- References:
- stack level parameter, David Manura
- Re: stack level parameter, Mark Hamburg
- Re: stack level parameter, steve donovan
- Re: stack level parameter, Mark Hamburg
- Re: stack level parameter, steve donovan
- Re: stack level parameter, Mark Hamburg
- Re: stack level parameter, M Joonas Pihlaja
- Re: stack level parameter, David Given
- Re: stack level parameter, Mark Hamburg
- Re: stack level parameter, M Joonas Pihlaja