[Haskell-cafe] Re: [Haskell] Read Instances for Data.Map and Data.Set

[Donald Bruce Stewart]

mai99dgf:
> Hi folks,
> 
> I was really annoyed by the fact that for Data.Map and Data.Set are no Read 
> instances declared, but Show instances are! I believe there should be some 
> kind of unwritten rule that in the standart lib the Show and Read instances 
> come pairwise and are fully compatible. 

There are some things that are Showable, but would be wrong to be
Readable. Dynamics come to mind. That's not the case with Map, though :)

(moved to haskell-cafe@ just in case :)

-- Don