[Haskell] Read Instances for Data.Map and Data.Set
maeder at tzi.de
Fri Oct 21 05:12:31 EDT 2005
Johannes Waldmann wrote:
> Georg made the point that if a type is an instance of Show,
> then it should also be an instance of Read, and read . show == id
That does (hopefully) happened now.
> I'd like to repeat my earlier point that it would be better
> if the user of the type can decide whether he wants
> some predefined Show/Read instances or roll his own.
It is really not an option (in current Haskell) to put Show/Read
instances in a separate module. Just consider if you want to combine a
couple of module were two modules rely on different instance
implementations. (A horror if you want to share code)
IT is, however, an option to add auxiliary (non-overloaded) utility
functions for showing and reading (parameterized of some separators).
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