[Haskell-cafe] Shrinking the Prelude: The "categorical" approach

Ross Paterson ross at soi.city.ac.uk
Thu Dec 21 18:36:05 EST 2006

On Thu, Dec 21, 2006 at 07:16:16PM +0100, Henning Thielemann wrote:
> About the question, whether functions should be provided in the most 
> general context, I refer to
>   http://www.haskell.org/haskellwiki/Slim_instance_declaration

Certainly we all agree that a module that defines instances should export
functions it uses that others can use in defining further instances,
but I don't see the point of this rule as stated.  What would we gain
if Ratio exported (+) on rationals with a different name?  Surely the
important thing is the reusable auxiliary functions, if any, since the
specialized method itself is available.

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