Copyright	(c) 2023-2025 Sayo contributors
License	MPL-2.0 (see the file LICENSE)
Maintainer	ymdfield@outlook.jp
Safe Haskell	None
Language	GHC2021

Data.Effect.Reader

Description

Effects that can be used to hold environmental values in the context. Environmental values are immutable and do not change across procedures, but you can modify the value within a local scope using the local operation.

Synopsis

ask :: forall r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Ask r :> es) => a r
local :: forall r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Local r :> es) => (r -> r) -> a b -> a b
runReader :: forall r (es :: [(Type -> Type) -> Type -> Type]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (forall (es' :: [Effect]). Applicative (Eff ff es'), Free c ff) => r -> Eff ff (Local r ': (Ask r ': es)) a -> Eff ff es a
asks :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Ask r :> es, Functor (Eff ff es), Free c ff) => (r -> a) -> Eff ff es a
runAsk :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), Free c ff) => r -> Eff ff (Ask r ': es) a -> Eff ff es a
runLocal :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), In (Ask r) es, Free c ff) => Eff ff (Local r ': es) a -> Eff ff es a
handleLocal :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), In (Ask r) es, Free c ff) => Local r ~~> Eff ff es
handleLocalFor :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), Free c ff) => Membership (Ask r) es -> Local r ~~> Eff ff es
ask' :: forall {k} (key :: k) r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Has key (Ask r) es) => a r
ask'' :: forall {k} (tag :: k) r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Tagged tag (Ask r) :> es) => a r
ask'_ :: forall r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, In (Ask r) es) => a r
local' :: forall {k} (key :: k) r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Has key (Local r) es) => (r -> r) -> a b -> a b
local'' :: forall {k} (tag :: k) r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Tagged tag (Local r) :> es) => (r -> r) -> a b -> a b
local'_ :: forall r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, In (Local r) es) => (r -> r) -> a b -> a b
data Ask r (a :: Type -> Type) b where
- Ask :: forall r (a :: Type -> Type). Ask r a r
data Local r (a :: Type -> Type) b where
- Local :: forall r (a :: Type -> Type) b. (r -> r) -> a b -> Local r a b

Documentation

ask :: forall r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Ask r :> es) => a r Source #

local :: forall r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Local r :> es) => (r -> r) -> a b -> a b Source #

runReader :: forall r (es :: [(Type -> Type) -> Type -> Type]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (forall (es' :: [Effect]). Applicative (Eff ff es'), Free c ff) => r -> Eff ff (Local r ': (Ask r ': es)) a -> Eff ff es a Source #

Interpret the Ask/Local effects.

asks :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Ask r :> es, Functor (Eff ff es), Free c ff) => (r -> a) -> Eff ff es a Source #

Obtains a value from the environment and returns it transformed by the given function.

runAsk :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), Free c ff) => r -> Eff ff (Ask r ': es) a -> Eff ff es a Source #

Interpret the Ask effect.

runLocal :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) a (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), In (Ask r) es, Free c ff) => Eff ff (Local r ': es) a -> Eff ff es a Source #

Interpret the Local effect.

handleLocal :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), In (Ask r) es, Free c ff) => Local r ~~> Eff ff es Source #

A handler for the Local effect.

handleLocalFor :: forall r (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Applicative (Eff ff es), Free c ff) => Membership (Ask r) es -> Local r ~~> Eff ff es Source #

A handler for the Local effect.

ask' :: forall {k} (key :: k) r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Has key (Ask r) es) => a r Source #

ask'' :: forall {k} (tag :: k) r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Tagged tag (Ask r) :> es) => a r Source #

ask'_ :: forall r a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, In (Ask r) es) => a r Source #

local' :: forall {k} (key :: k) r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Has key (Local r) es) => (r -> r) -> a b -> a b Source #

local'' :: forall {k} (tag :: k) r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, Tagged tag (Local r) :> es) => (r -> r) -> a b -> a b Source #

local'_ :: forall r b a (es :: [Effect]) (ff :: (Type -> Type) -> Type -> Type) (c :: (Type -> Type) -> Constraint). (Free c ff, a ~ Eff ff es, In (Local r) es) => (r -> r) -> a b -> a b Source #

data Ask r (a :: Type -> Type) b where #

An effect that holds a value of type r in the context (environment).

Constructors

Ask :: forall r (a :: Type -> Type). Ask r a r

Obtain a value from the environment.

Instances

Instances details

FirstOrder (Ask r)
Instance details Defined in Data.Effect
PolyHFunctor (Ask r)
Instance details Defined in Data.Effect
HFunctor (Ask r)
Instance details Defined in Data.Effect Methods hfmap :: (forall x. f x -> g x) -> Ask r f a -> Ask r g a #
type FormOf (Ask r)
Instance details Defined in Data.Effect type FormOf (Ask r) = 'Polynomial
type LabelOf (Ask r)
Instance details Defined in Data.Effect type LabelOf (Ask r) = AskLabel
type OrderOf (Ask r)
Instance details Defined in Data.Effect type OrderOf (Ask r) = 'FirstOrder

data Local r (a :: Type -> Type) b where #

An effect that locally modifies the value held in the environment.

Constructors

Local	Locally modifies the value held in the environment.
Fields :: forall r (a :: Type -> Type) b. (r -> r) A function that transforms the original value to the modified value. -> a b The local scope where the modification is applied. -> Local r a b

Instances

Instances details

PolyHFunctor (Local r)
Instance details Defined in Data.Effect
HFunctor (Local r)
Instance details Defined in Data.Effect Methods hfmap :: (forall x. f x -> g x) -> Local r f a -> Local r g a #
type FormOf (Local r)
Instance details Defined in Data.Effect type FormOf (Local r) = 'Polynomial
type LabelOf (Local r)
Instance details Defined in Data.Effect type LabelOf (Local r) = LocalLabel
type OrderOf (Local r)
Instance details Defined in Data.Effect type OrderOf (Local r) = 'HigherOrder