capability-0.5.0.1: Extensional capabilities and deriving combinators
Safe HaskellSafe-Inferred
LanguageHaskell2010

Capability.Constraints

Description

This module defines helper types and type families for working with sets of capabilities.

Synopsis

Documentation

type family All (xs :: [k -> Constraint]) a :: Constraint where ... Source #

Type family used used to express a conjunction of constraints over a single type.

Examples:

All '[Num, Eq] Int
  -- Equivalent to: (Num Int, Eq Int)

All '[HasReader "foo" Int, HasSink "bar" Float] m
  -- Equivalent to: (HasReader "foo" Int m, HasSink "bar" Float m)

Equations

All '[] a = () 
All (x ': xs) a = (x a, All xs a) 

type Capability = (Type -> Type) -> Constraint Source #

A Capability takes a type constructor Type -> Type (e.g., a monad) and returns a Constraint. Examples of capabilities includ: HasReader "foo" Int, MonadIO, …

data Constraint #

The kind of constraints, like Show a

data Dict a where #

Values of type Dict p capture a dictionary for a constraint of type p.

e.g.

Dict :: Dict (Eq Int)

captures a dictionary that proves we have an:

instance Eq 'Int

Pattern matching on the Dict constructor will bring this instance into scope.

Constructors

Dict :: forall a. a => Dict a 

Instances

Instances details
HasDict a (Dict a) 
Instance details

Defined in Data.Constraint

Methods

evidence :: Dict a -> Dict a #

a :=> (Read (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: a :- Read (Dict a) #

a :=> (Monoid (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: a :- Monoid (Dict a) #

a :=> (Enum (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: a :- Enum (Dict a) #

a :=> (Bounded (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: a :- Bounded (Dict a) #

() :=> (Eq (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: () :- Eq (Dict a) #

() :=> (Ord (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: () :- Ord (Dict a) #

() :=> (Show (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: () :- Show (Dict a) #

() :=> (Semigroup (Dict a)) 
Instance details

Defined in Data.Constraint

Methods

ins :: () :- Semigroup (Dict a) #

a => Bounded (Dict a) 
Instance details

Defined in Data.Constraint

Methods

minBound :: Dict a #

maxBound :: Dict a #

a => Enum (Dict a) 
Instance details

Defined in Data.Constraint

Methods

succ :: Dict a -> Dict a #

pred :: Dict a -> Dict a #

toEnum :: Int -> Dict a #

fromEnum :: Dict a -> Int #

enumFrom :: Dict a -> [Dict a] #

enumFromThen :: Dict a -> Dict a -> [Dict a] #

enumFromTo :: Dict a -> Dict a -> [Dict a] #

enumFromThenTo :: Dict a -> Dict a -> Dict a -> [Dict a] #

Eq (Dict a) 
Instance details

Defined in Data.Constraint

Methods

(==) :: Dict a -> Dict a -> Bool #

(/=) :: Dict a -> Dict a -> Bool #

(Typeable p, p) => Data (Dict p) 
Instance details

Defined in Data.Constraint

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Dict p -> c (Dict p) #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Dict p) #

toConstr :: Dict p -> Constr #

dataTypeOf :: Dict p -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Dict p)) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Dict p)) #

gmapT :: (forall b. Data b => b -> b) -> Dict p -> Dict p #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Dict p -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Dict p -> r #

gmapQ :: (forall d. Data d => d -> u) -> Dict p -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Dict p -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Dict p -> m (Dict p) #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Dict p -> m (Dict p) #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Dict p -> m (Dict p) #

Ord (Dict a) 
Instance details

Defined in Data.Constraint

Methods

compare :: Dict a -> Dict a -> Ordering #

(<) :: Dict a -> Dict a -> Bool #

(<=) :: Dict a -> Dict a -> Bool #

(>) :: Dict a -> Dict a -> Bool #

(>=) :: Dict a -> Dict a -> Bool #

max :: Dict a -> Dict a -> Dict a #

min :: Dict a -> Dict a -> Dict a #

a => Read (Dict a) 
Instance details

Defined in Data.Constraint

Show (Dict a) 
Instance details

Defined in Data.Constraint

Methods

showsPrec :: Int -> Dict a -> ShowS #

show :: Dict a -> String #

showList :: [Dict a] -> ShowS #

Semigroup (Dict a) 
Instance details

Defined in Data.Constraint

Methods

(<>) :: Dict a -> Dict a -> Dict a #

sconcat :: NonEmpty (Dict a) -> Dict a #

stimes :: Integral b => b -> Dict a -> Dict a #

a => Monoid (Dict a) 
Instance details

Defined in Data.Constraint

Methods

mempty :: Dict a #

mappend :: Dict a -> Dict a -> Dict a #

mconcat :: [Dict a] -> Dict a #

NFData (Dict c) 
Instance details

Defined in Data.Constraint

Methods

rnf :: Dict c -> () #