[Haskell-beginners] Help with meaningful error message...

Sean Charles sean at objitsu.com
Tue Jun 7 23:44:54 CEST 2011

OK, I am losing enough hair and accruing follicular damage more than I 
can take tonight, what is wrong, what have I done that is stupid and 
wrong etc...

   let routes = forwardRoutes M.empty csvdata  -- [Record] from Text.CSV


forwardRoutes m [] = m
forwardRoutes m (row:rows) =
   case M.lookup m (row !! 0) of
     Just route -> M.update m (row !! 1):route
     Nothing -> M.insert from []
   forwardRoutes m rows

error: scread.hs:101:2: parse error on input `forwardRoutes'

Um yeah, thanks, that's really helping me figure it out.

All I wanted to do was build a map of keys and values where each value 
is a list that gradually accumulates(!) every row that ends at (!!1)  
from the same location (!!0) of my spreadsheet. I started off zipping 
with 'repeat []' and stuff but I just want to know what I have done to 
annoy the compiler enough to want to taunt me with that message.

And, on the verge of posting I think the above code won't work anyway 
because I am not passing the new Map from 'insert' through.......


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