I’ve looked into the source code of DBIx::Class recently and found that I don’t understand a thing (though I mastered a couple tricks while trying to).
So my question is: which CPAN modules are a must read for someone who wants to learn, and in what order?
If I were doing the same I’d probably start with the ::Tiny space. I’d expect it to be less distracting—fewer edge cases cluttering things—and more idiomatic—terseness lends itself to Perl idiom—in general.
Then I’d attack the medium–large nodes from this excellent document—Map of the CPAN’s authors (large PDF). Update: Web version. Zoom into the bigger nodes then search on search.cpan.org for them. The largest nodes sometimes represent old-school and while exceptional code exists in the old school, not a lot of good teaching examples do (so I say). Authors like Miyagawa, Kennedy, and Kogman come to mind immediately as worth reviewing. There are plenty of others. Basically any module you see recommended here often, look up the author and poke around his or her other packages, as it were.