| Safe Haskell | Trustworthy |
|---|---|
| Language | Haskell2010 |
Type.Reflection.Compat
Synopsis
- module Type.Reflection
- withTypeable :: forall k (a :: k) (rep :: RuntimeRep) (r :: TYPE rep). TypeRep a -> (Typeable a => r) -> r
- pattern TypeRep :: () => Typeable a => TypeRep a
- decTypeRep :: forall k1 k2 (a :: k1) (b :: k2). TypeRep a -> TypeRep b -> Either ((a :~~: b) -> Void) (a :~~: b)
Documentation
module Type.Reflection
withTypeable :: forall k (a :: k) (rep :: RuntimeRep) (r :: TYPE rep). TypeRep a -> (Typeable a => r) -> r #
Use a TypeRep as Typeable evidence.
The TypeRep pattern synonym brings a Typeable constraint into
scope and can be used in place of withTypeable.
f :: TypeRep a -> ..
f rep = withTypeable {- Typeable a in scope -}
f :: TypeRep a -> ..
f TypeRep = {- Typeable a in scope -}
pattern TypeRep :: () => Typeable a => TypeRep a #
A explicitly bidirectional pattern synonym to construct a concrete representation of a type.
As an expression: Constructs a singleton TypeRep a given a
implicit 'Typeable a' constraint:
TypeRep @a :: Typeable a => TypeRep a
As a pattern: Matches on an explicit TypeRep a witness bringing
an implicit Typeable a constraint into scope.
f :: TypeRep a -> ..
f TypeRep = {- Typeable a in scope -}
Since: base-4.17.0.0