Well, closures are just a special case of code ref, so the answer is yes. Both Data::Dumper and Data::Dump::Streamer can dump closures as they both can dump code references.

Incidentally this is one of those common misnomers that seem to pop up in Perl circles. Theres a habit of calling "annoymous code refs" as closures, because normally its not obvious that named subroutines can also be closures. And from a perl point of view you never actually interact with a subroutine (beyond calling it) except by reference. So from a given piece of codes POV there is no difference between a "closure", an "anonymous subroutine that isnt a closure" or a "reference to a named subroutine". They are all just references to a CODE object. This holds true for all of perls types pretty much. There is no difference between a "reference to a named array" and an "anonymous array" etc etc.

sub Foo {print "Foo!\n"}         # named subroutine / non-closure
my $foo= sub { print "Bar!\n"};  # anonymous / non-closure
my $bar= sub { $foo->() };       # anonymous / closure
sub FooBar { $bar->() }          # named subroutine / closure

sub takes_a_callback {
  my $callback=shift;
  $callback->();
}

takes_a_callback($_) foreach \&Foo,$foo,$bar,\&FooBar;
[download]

In the above case takes_a_callback() can't tell if it what it recieves is a closure or not, nor if its a named subroutine. All it knows that if the object actually is a code ref it will execute it with no arguments. If its isnt a code ref it'll die.

HTH