marlowsd at gmail.com
Sat Sep 27 08:47:22 EDT 2008
kahl at cas.mcmaster.ca wrote:
> Simon Marlow <marlowsd at gmail.com> wrote:
> > We must have the property that the imports of a module do not affect
> > its API - and the only way to have this property is to avoid orphan
> > instances in library APIs.
> To be more precise, I would say that each orphan instance in a library API
> must be the only export of a dedicated visible module,
> and only exported by that module.
> (The only importers of orphan instances are typically Main modules,
> or ``almost-Main'' modules.)
Why do you believe that? We seem to have evidence to the contrary, with
Control.Monad.Instances being imported by library modules.
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