July 9th, 2003

beartato phd

(no subject)

An enlightening discussion with adam! Now I feel much less sure about nearly everything. Yay! It is far too late in the morning for me to be sure whether I am being sarcastic or not. I think I am not. It is refreshing to question basic assumptions.
beartato phd

(no subject)

Someone oughta revoke my progamming license. Failing to apply substitutions, failure to maintain typing invariants, reckless debugging instrumentation. Sheesh.
beartato phd

(no subject)

I love advisor meetings not going horribly at all!
Especially when I expect them to!

Yes, so discovered what the bug was in the middle of it. Things were falling into a default case in weak head-normalization when they shouldn't have. Very strange! It's things like these that make me upset that some ML hackers don't mind letting non-exhaustive matches remain in their programs, because the notion of not covering all the cases the way you expect seems to be such a common source of errors for me. Sadly, even if the makers of twelf had programmed with such discipline, it wouldn't have helped me find this particular bug, because there was a fall-through case that caught the new possiblity, (making the match indeed exhaustive, even though I would never notice one more non-exhaustive match warning in the huge swaths of them) and did the wrong thing with it. I wonder how one might help the compiler alert the programmer to such subtle dangers.