Following my positive experience with Claude Code and JavaScript/PHP yesterday, I tried using Perl today. This time, I spent a lot of time optimising the CLAUDE.md content before starting the code analysis. I asked it to analyse a Perl module containing some functions that I wrote several months ago, checking for errors and suggesting improvements. It found one error and suggested some improvements. However, some of these improvements involved Perl idioms that I, a Delphi user rather than a Perl user, did not like, so I told it not to suggest these again. It heeded that command.
It suggested some good changes to regular expressions, such as this:
\d\d\d -> \d{3}
I told it to make that change and to add a short comment for my future self explaining what the {n} means. It did that and surprised me by adding the comment in German, even though I had been communicating with it in English. However, the other comments in that module are in German.
As I am more proficient in Perl than JavaScript, I think I am a better judge of the code it produces today than yesterday. So far, I am still impressed. However, I’m not sure whether I am more productive. Had I not wanted to test Claude Code, I probably wouldn’t have revisited that code at all. It has been in production for several months, so why touch it?