Perl has grep/map/sort since probably forever (actually, sort() starts appearing since Perl 2.0). But even now, reduce is still not a builtin in Perl 5 (though available via List::Util), so doing reduce is probably not something that comes as naturally to Perl programmers. Meanwhile Ruby, JavaScript, and even PHP have their reduce operation builtin.

But then, reduce is "not really that useful" (you can just replace it with a simple for loop). So much that Python 3.0 now removes the function from the global namespace and reduces it (pun intended) to a mere member of funct…

Here are some notes I made while hacking on Language::Expr::Compiler::JS. Of course, there are a million differences between the two, but these focus mostly on operators and types. Hope it can be useful.

• Double vs single quotes. There are practically no functional differences between double-quoted string and single-quoted one in JavaScript. In Perl, single quotes do not interpret escape sequences other than \\ and \', but in JavaScript both single- and double-quoted strings interpret the same set of escape sequences. …

It's a brilliant idea: bank on JSON's popularity and more widespread implementations, add some of the important YAML features not present in JSON on top of it. The result is JSYNC, along with its preliminary CPAN module. (I'd probably picked a different name and choose something like "\" for prefix instead of ".", but hey, it's not my project :-)

A few months ago I was really desperate with the YAML situation in Perl. We have the largest number of YAML implementations, but none of them are good enough…

After blogging about my small patch to Data::Dump, I contacted Gisle Aas. He is quite responsive and finally comes up with a new release (1.16) of Data::Dump containing the cool new filter feature. My previous example after converted to use the new feature becomes:

$ perl -MData::Dump=dumpf -MDateTime -e'dumpf(DateTime->now, sub { my ($ctx, $oref) = @_; return unless $ctx->class eq "DateTime"; {dump=>qq([$oref])} })'
[2010-06-09T12:22:58]

This filter mechanism is …