I didn’t have to make many changes to Chapter 11: Configuration. This is mostly a stable part of the Perl ecosystem. I updated a few minor things.
Readonly is out, Const::Fast is in. I only talk about constants for a short section where I write about a particular way (anti-pattern even) to configure programs. The Readonly module hasn’t been updated in years. It uses tie to perform its magic and has several interesting edge cases from that as you can see in its RT queue. Leon Timmermans replaced it with Const::Fast. It uses almost the same interface but “by doing everything the opposite way Readonly does it.” I’ve asked Eric Roode, Readonly‘s maintainer, if I can get it into Github and have the community update it. I’ll see how that goes.
In two places I had mentioned Google Code Search, the now dead project that was part of Google’s mission to “organize the world’s information and make it universally accessible and useful”. Instead, I found Ohloh’s code search. In the chapter, I look for “DON’T EDIT BELOW THIS LINE” and config.pl to show how common those are.
AppConfig is out. I don’t think it was widely used even when it was fresh, but it’s as old as the first edition of Mastering Perl. Instead, I mentioned JSON and YAML, although I’ll cover those in Chapter 14: Lightweight Persistence. I should survey people to see how they are configuring things nowadays.
Do you have anything else I should include or update? See what I have so far by reading it through Atlas.