| Copyright | (C) 2011-2015 Edward Kmett (C) 2015 Ørjan Johansen (C) 2016 David Feuer |
|---|---|
| License | BSD-style (see the file LICENSE) |
| Maintainer | Edward Kmett <ekmett@gmail.com> |
| Stability | experimental |
| Portability | non-portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Data.Constraint.Forall
Description
This module uses a trick to provide quantification over constraints.
- type family Forall (p :: k -> Constraint) :: Constraint
- inst :: forall p a. Forall p :- p a
- class Forall (ComposeC p f) => ForallF p f
- instF :: forall p f a. ForallF p f :- p (f a)
- type Forall1 p = Forall p
- inst1 :: forall p f. Forall p :- p f
- class Forall (Q p t) => ForallT p t
- instT :: forall p t f a. ForallT p t :- p (t f a)
- type family ForallV :: k -> Constraint
- class InstV p c | k c -> p where
- forall :: forall p. (forall a. Dict (p a)) -> Dict (Forall p)
Documentation
type family Forall (p :: k -> Constraint) :: Constraint Source #
A representation of the quantified constraint forall a. p a.
class Forall (ComposeC p f) => ForallF p f Source #
A representation of the quantified constraint forall a. p (f a).
instF :: forall p f a. ForallF p f :- p (f a) Source #
Instantiate a quantified ForallF p fa.
inst1 :: forall p f. Forall p :- p f Source #
Instantiate a quantified constraint on kind * -> *.
This is now redundant since inst
class Forall (Q p t) => ForallT p t Source #
A representation of the quantified constraint forall f a. p (t f a).
instT :: forall p t f a. ForallT p t :- p (t f a) Source #
Instantiate a quantified ForallT p tf and a.
type family ForallV :: k -> Constraint Source #
A representation of the quantified constraint
forall a1 a2 ... an . p a1 a2 ... an, supporting a variable number of
parameters.
class InstV p c | k c -> p where Source #
Instantiate a quantified ForallV pc, where
c ~ p a1 a2 ... an.
Minimal complete definition
Instances
| (~) Constraint p c => InstV Constraint p c Source # | |
| InstV (k2 -> k3) (p a) c => InstV (k1 -> k2 -> k3) p c Source # | |
| (~) Constraint (p a) c => InstV (k -> Constraint) p c Source # | |