THInstanceReification

Fixed versions of reifyInstances and isInstance as per the following ghc issue: https://ghc.haskell.org/trac/ghc/ticket/7066.

Documentation

reifyProperInstances :: Name -> [Type] -> Q [InstanceDec]

Same as reifyInstances, but also checks the constraints.

isProperInstance :: Name -> [Type] -> Q Bool

Same as isInstance, but also checks the constraints.

typesSatisfyDecConstraints :: [Type] -> InstanceDec -> Q Bool

Analyze the constraints of the provided instance dec to be satisfied by the provided types.

Note that this function does not analyze the equality constraints (F a ~ Bool). It simply considers them to be true.