On Sun, Sep 22, 2013 at 11:07 AM, TP <paratribulati...@free.fr> wrote: > My misunderstanding came from a confusion between a "context" and a > "constraint". The context is what is before the =>, and the constraint is > what is after, i.e. the main part of the instance declaration.
Hi TP, I think context and constraint mean the same thing. The haskell report uses the word context for <http://www.haskell.org/onlinereport/decls.html> for the whole list and constraint for one part of that list (Eq a). With the extension -XConstraintKinds both of those are called Constraint. In other words: > instance Context => InstanceHead > > instance (Constraint, Constraint2) => InstanceHead Regards, Adam _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
