[Haskell] RE: Hugs/GHC incompatibility

[Simon Peyton-Jones]

| I think, I've found the problem. GHC seems to not implement
Data.Array.array
| correctly. The implementation doesn't adhere to the following sentence
from
| the Data.Array.IArray.array documentation:
|     If any two associations in the list have the same index, the value
at that
|     index is undefined.
| Could this be fixed?

It's a documented incompatibility with H98 
	
http://www.haskell.org/ghc/docs/latest/html/users_guide/bugs-and-infelic
ities.html#HASKELL98-DIVERGENCE

We don't intend to fix this because fixing it will have a significant
overhead on every array construction. 

Actually I rather think H98 should have left the behaviour of double
indices undefined, rather than defining it to be bottom.  But it's too
late now.

Simon