Safe Haskell	None
Language	Haskell98

Control.Effect.Reader

Synopsis

Documentation

data Reader s a Source

Provides a effect-parameterised version of the class reader monad. Effects are sets of variable-type pairs, providing an effect system for reader effects.

Constructors

IxR
Fields runReader :: Set s -> a

Instances

Effect [*] Reader
Subset s t => Subeffect [*] Reader s t	If `s` is a subset of `t` then, `s` is a subeffect of `t`
type Unit [] Reader = []
type Plus [] Reader f g = Union f g
type Inv [] Reader f g = (IsSet f, IsSet * g, Split f g (Union * f g))

ask :: Var v -> Reader `[v :-> a]` a Source

ask for a variable v of type a, raising an effect

merge :: Unionable s t => (a -> Reader (Union s t) b) -> Reader s (a -> Reader t b) Source

Provides a way to emulated the ImplicitParams features of GHC/Haskell

data k :-> v :: Symbol -> * -> *

Constructors

(Var k) :-> v

Instances

(Show (Var k), Show v) => Show ((:->) k v)
(Monoid u, Nubable ((:) * ((:->) k u) s)) => Nubable ((:) * ((:->) k u) ((:) * ((:->) k u) s))	Define the operation for removing duplicates using mappend
Update ((:) * ((:->) u ((:!) b s)) as) as' => Update ((:) * ((:->) v ((:!) a W)) ((:) * ((:->) u ((:!) b s)) as)) as'
Update ((:) * ((:->) v ((:!) a R)) as) as' => Update ((:) * ((:->) v ((:!) a W)) ((:) * ((:->) v ((:!) b R)) as)) as'
Update ((:) * ((:->) u ((:!) b s)) as) as' => Update ((:) * ((:->) v ((:!) a R)) ((:) * ((:->) u ((:!) b s)) as)) ((:) * ((:->) v ((:!) a R)) as')
type Cmp * ((:->) v a) ((:->) u b) = CmpSymbol v u

data Var k :: Symbol -> * where

Constructors

Var :: Var k
X :: Var "x"
Y :: Var "y"
Z :: Var "z"

Instances

Show (Var v)
Show (Var "x")
Show (Var "y")
Show (Var "z")

class Subset s t

Minimal complete definition

subset

Instances

Subset ([] ) ([] )
Subset ([] ) ((:) x t)
Subset s t => Subset ((:) * x s) ((:) * x t)

data Set n :: [*] -> * where

Constructors

Empty :: Set ([] *)
Ext :: e -> Set s -> Set ((:) * e s)

Instances

(Show e, Show' (Set s)) => Show (Set ((:) * e s))
Show (Set ([] *))
(Show' (Set s), Show e) => Show' (Set ((:) * e s))
Show' (Set ([] *))