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- Subject: Re: setfenv/getfenv
- From: David Kolf <kolf@...>
- Date: Tue, 12 Jan 2010 19:01:18 +0100
A.S. Bradbury wrote:
>> But in order to address the "reuse"-issue again, with loadin() it would
>> only be easy to reuse the source and compile the function each time again.
> I may be missing something, but does this solve the multiple reuse problem?
> function multienv(funcstr)
> return loadstring([[
> return function(_G)
> in _G do
> return function()
No, that would operate on compiling source code for each environment.
That is already possible with the new loadin () function. What I was
looking for was reusing the function chunk without the need to compile
it again each time and without the need to copy it in extra strings
using string.dump ().
I still don't quite understand why a feature that wasn't broken in the
first place (setfenv/getfenv) is supposed to be removed. That these
functions are extremely powerful and can break a lot of things is
obvious. You would never put them inside a sandbox. But so are
getmetatable/setmetatable. You can also break other code using them.
The new "in ... do ... end" is a good addition for some uses setfenv()
was used for. loadin () can be used as a safer loadstring (), too. But I
still would like to keep the old functions.