To get at your question more directly, it is true that closures in Perl do not have to be anonymous, and as others have said, yes technically your example is a closure. But the canonical case for named closures is something like this in Lisp (forgive my somewhat rusty Lisp):
(defun foo (n)
(labels ((f (i) (+ i m)))
f)
)
and you might be tempted to write the Perl equivalent like this:
sub foo {
my $n = shift;
sub f {
my $i = shift;
return $i+$n;
}
return \&f;
}
But this will not work, because the inner sub "f" is really global and the closure won't behave like you want it to. The solution is to make f anonymous:
sub foo {
my $n = shift;
my $f = sub {
my $i = shift;
return $i+$n;
};
return $f;
}
And this is the main reason why closures in Perl are usually anonymous.
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