Comment by beeworker

Not really, sorry. I had forgotten that the first letter is compared case sensitively as I remembered from Nimrod it was all insensitive. But I still think for nearly all cases in real world code you can instead of using nimgrep be equally served by a case insensitive search on (nimidentifier|nim_identifier) even if it's technically possible to have other variants or a mismatch, which you can grep out as a second step anyway, with the capital N.