[downerending]

I can see it either way, but for a tiny program this could be handy. For a larger program that already has multiple source files, it seems like it'd be better to keep it in a separate file (to make the git diffs easier to follow, for example).

It would be better if it was namespace'd in some way, at least by using a common unusual prefix for all of the non-local symbols. It wouldn't be hard to clash with the chosen names.