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Postings from August 2013
On 08/01/2013 01:35 AM, Ricardo SIGNES via RT wrote: > On Tue Jul 30 16:05:09 2013, sprout wrote: >> In short: closures close over variables, not lexical scopes, unless >> string eval is involved. (So one can work around this by including eval >> "" in the sub.) > > When did this become true in practice? I think it has "always" been like that. > It does not match up with what I take to be common definition of closures as enclosing a > complete environment. I agree that PadWalker is letting Perl programmers go beyond the realm > of polite behavior, but let's put that aside. This is quite interesting as I've always knownsumed[1] that it's variables being closed over, not full environments, for the reasons Dave described. And that is as a Perl user. It's only very recently with PLua that I've looked into how closures work and tried to meddle with them. > Why shouldn't this program be able to print 2? Because closing over variables (which it has always been, I believe) happens at run-time apart from the eval "" exception. > What are the practical wins to making closure per-variable instead of per-environment? This was already answered, I believe. --Steffen [1] Sounds better than assknown, dunnit?Thread Previous | Thread Next