Today while reading LWN, I learned about the Flymake minor mode for Emacs. This software does on-the-fly compile checking, kind of like the on-the-fly spell checking that has become popular in many editors.
Whenever Emacs becomes idle, flymake shells out and runs "perl -c" on your code. It parses the output for errors. Back in Emacs, flymake highlights the offending code. Take a look at a screenshot I created, showing flymake responding to a missing semicolon.
Flymake appears to be pre-installed under Emacs 22
Has anyone else tried this?
It seems nice on trivial code I've tested, but it seems to disable itself a little too readily. It bases its decisions purely on the filename extension implied by the buffer name, instead of checking in with the major mode. It has trouble guessing @INC paths too, as can be expected. For example, I tried it on some Perl::Critic code, but because 'lib' wasn't in @INC, flymake turned itself off after one compile failure.