Re^5: Integer detection concept

Which is never called outside the context of the same lexical pad. All it does is affect a variable outside of its scope. The key is that it's been assigned to local( $SIG{WARN} ) - the sub disappears when the scope goes away.

It's kinda the opposite of a closure, if you think about it. Instead of a subroutine being called outside the scope of a lexical variable yet still affecting it, you have a variable being used outside of the lexical scope of the subroutine that affected it.

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Re^6: Integer detection concept by Tanktalus (Canon) on Jan 19, 2005 at 18:00 UTC
I would think that's still a closure. Since it is called outside of the lexical scope of the lexical variable. When a signal is caught, we're in the signal handling part of the perl runtime. That is far, far outside of the lexical scope of $warn. So, Perl_warn_handler() calls the coderef it is given, which affects $warn, which is outside of the scope of Perl_warn_handler(). That, to me, is a closure.	[reply]

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Re^6: Integer detection concept
by Tanktalus (Canon) on Jan 19, 2005 at 18:00 UTC

I would think that's still a closure. Since it is called outside of the lexical scope of the lexical variable. When a signal is caught, we're in the signal handling part of the perl runtime. That is far, far outside of the lexical scope of $warn. So, Perl_warn_handler() calls the coderef it is given, which affects $warn, which is outside of the scope of Perl_warn_handler(). That, to me, is a closure.

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