Simon Peyton-Jones wrote:
3. Dictionaries are packaged in data constructors
This feature has been often requested, becuase it allows you to
package a dictionary into an ordinary (non-existential) data type, and
be able to use it.
Indeed, one can now simply reify class instances:
data NumInst a where
MkNumInst :: Num a => NumInst a
intInst :: NumInst Int
intInst = MkNumInst
plus :: NumInst a -> a -> a -> a
plus MkNumInst p q = p + q
Expect a whole new batch of type shenanigans from Oleg.
--
Ashley Yakeley
Seattle, WA
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