Interaction and ambiguous type variables
alastair at reid-hoffmann.net
Thu Jul 3 09:25:35 EDT 2003
Could this problem be solved by having interactive environments (ghci, Hugs)
extend the default rules so that they don't just apply for Num contexts but
also for Show contexts?
For example, with a default declaration
default ((), Integer, Double)
we would have the ambiguous type
show  :: Show a => String
which would be resolved by choosing a=().
(Note that I'm using () instead of adding a new type 'Void'. This seems nicer
from a language-design viewpoint and I'd guess is nicer for someone trying to
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