
Fernan Bolando
Hi all
I recently used 2 hours of work looking for a bug that was causing
Program error: Prelude.!!: index too large
This is not very informative. It did not give me a hint which function was causing this. In C adding a few printf would have helped me, but in haskell I was not sure how to do that. Can anybody point me to some debuggin method everyone uses.
After 2 hours I did find the bug eventually. The code can be viewed here. Maybe some reformatting of the code would make finding bugs easier? http://plan9.bell-labs.com/sources/contrib/fernan/escomma/
I wonder if your code has to use !! at all? I took a look at a random module from the above link, and (without making much attempt at understanding it), I'd guess that using accumArray and friends would be more appropriate. Mostly you don't want to be doing indexing on lists. -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk