(ichimunki) re x 2: Why are closures cool, continued?

[ichimunki]

Data::Dumper is going to give out "DUMMY" as the value for any sub, not just a closure. The contents of a subroutine are represented internally with a variety byte code I believe, which would look like so much nonsense if it were printed in the contents of a Data::Dumper dump. Contrast to scalars (or hash keys or hash/array values made from scalars) and to references. Scalars eventually turn out to be some sequence of characters, and references inside a data structure can be represented with brackets and braces.

'perldoc Data::Dumper' has more info on this in the BUGS section.

[theorbtwo]

As to "[t]he contents of a subroutine [being] represented internally with a variety [of] byte code", you're both right and wrong (as is so often the case when talking about internals). The internals do deal with coderefs as pointing to a bunch of bytecode, but that bytecode is not inherently serializable; it has lots of pointers in it. Moreover (without resorting to Devel:: or B:: modules), it isn't accessable with Perl code.

The perl6 analog of Data::Dumper will be able to dump coderefs as Parrot assembler (pasm); one of the cool side-effects of going to an explicit VM.

Thanks,
James Mastros,
Just Another Perl Scribe