Henning Thielemann
On Thu, 16 Jul 2009, Fernan Bolando wrote:
Hi all
I recently used 2 hours of work looking for a bug that was causing
Program error: Prelude.!!: index too large
A good way to avoid such problems is to avoid partial functions at all. (!!) is also inefficient. Is it possible to define the function in terms of foldl?
I've looked at the code a bit more, and, with apologies to the original poster, it doesn't look much like Haskell. For example, in http://plan9.bell-labs.com/sources/contrib/fernan/escomma/Circuit.hs there's stuff beginning with tADM :: Int tADM = 1 tVSRC :: Int tVSRC = 2 tISRC :: Int tISRC = 3 ... that I think probably should be data Something = ADM | VSRC | ISRC ... deriving (Enum, ...) though when I get to "(((fst z0)!!pMSET)!!pMTYPE) == mOP" I'm at a loss to determine quite what the intention is. Maybe it should be an array indexed by enum types, maybe a function, maybe something that can be pattern matched on? I don't know. -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk