Moduleeffectful-core-2.3.0.1Haskell2010

Effectful.Internal.Env

5 types
16 values

Packageeffectful-core-2.3.0.1
Exports23
LanguageHaskell2010
LicenceBSD-3-Clause
SourceEnv.hs

The environment

2 declarations

datadata Env (es :: [Effect])

A strict (WHNF), thread local, mutable, extensible record indexed by types of kind Effect.

Warning: the environment is a mutable data structure and cannot be simultaneously used from multiple threads under any circumstances.

In order to pass it to a different thread, you need to perform a deep copy with the cloneEnv funtion.

Offers very good performance characteristics for most often performed operations:

Extending: O(n), where n is the size of the effect stack.
Shrinking: O(1).
Indexing via (:>): O(1)
Modification of a specific element: O(1).
Getting a tail: O(1).
Cloning: O(N), where N is the size of the Storage.

Constructors

Env
- envOffset :: !Int
- envRefs :: !PrimArray Int
- envStorage :: !IORef' Storage

datadata Storage

A storage of effects.

Constructors

Storage
- stSize :: !Int
- stVersion :: !Int
- stVersions :: !MutablePrimArray RealWorld Int
- stEffects :: !SmallMutableArray RealWorld Any
- stRelinkers :: !SmallMutableArray RealWorld Any

Relinker

newtypenewtype Relinker (a :: Effect -> Type) (b :: Effect) where

A function for relinking Env objects stored in the handlers and/or making a deep copy of the representation of the effect when cloning the environment.

Constructors

Relinker :: ((forall (es :: [Effect]). Env es -> IO (Env es)) -> a b -> IO (a b)) -> Relinker a b

valuedummyRelinker :: Relinker rep e

A dummy Relinker.

Dispatch

4 declarations

datadata Dispatch

A type of dispatch. For more information consult the documentation in Effectful.Dispatch.Dynamic and Effectful.Dispatch.Static.

Constructors

Dynamic
Static SideEffects

datadata SideEffects

Signifies whether core operations of a statically dispatched effect perform side effects. If an effect is marked as such, the runStaticRep family of functions will require the IOE effect to be in context via the MaybeIOE type family.

NoSideEffects WithSideEffects

familytype family DispatchOf (e :: Effect) :: Dispatch

Dispatch types of effects.

Instances16DispatchOf, …

type DispatchOf Fail = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad
type DispatchOf IOE = 'Static 'WithSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad
type DispatchOf NonDet = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad
type DispatchOf Prim = 'Static 'WithSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad
type DispatchOf (Error e) = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.Error.Dynamic
type DispatchOf (Error e) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Error.Static
type DispatchOf (Labeled label e) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Labeled
type DispatchOf (Provider e input f) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Provider
type DispatchOf (Reader r) = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.Reader.Dynamic
type DispatchOf (Reader r) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Reader.Static
type DispatchOf (State s) = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.State.Dynamic
type DispatchOf (State s) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.State.Static.Local
type DispatchOf (State s) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.State.Static.Shared
type DispatchOf (Writer w) = 'DynamicDefined in effectful-core-2.3.0.1 · Effectful.Writer.Dynamic
type DispatchOf (Writer w) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Writer.Static.Local
type DispatchOf (Writer w) = 'Static 'NoSideEffectsDefined in effectful-core-2.3.0.1 · Effectful.Writer.Static.Shared

familytype family EffectRep (d :: Dispatch) :: Effect -> Type

Internal representations of effects.

Instances2EffectRep

type EffectRep 'Dynamic = HandlerDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad · orphan
type EffectRep ('Static sideEffects) = StaticRepDefined in effectful-core-2.3.0.1 · Effectful.Internal.Monad · orphan

Operations

5 declarations

valueemptyEnv :: IO (Env '[])

Create an empty environment.

valuecloneEnv :: Env es -> IO (Env es)

Clone the environment to use it in a different thread.

valuerestoreEnv

:: Env es
Destination.
-> Env es
Source.
-> IO ()

Restore the environment from its clone.

valuesizeEnv :: Env es -> IO Int

Get the current size of the environment.

valuetailEnv :: Env (e ': es) -> IO (Env es)

Access the tail of the environment.

Modification of the effect stack

valueconsEnv

:: EffectRep (DispatchOf e) e
The representation of the effect.
-> Relinker (EffectRep (DispatchOf e)) e
-> Env es
-> IO (Env (e ': es))

Extend the environment with a new data type.

valueunconsEnv :: Env (e ': es) -> IO ()

Shrink the environment by one data type.

Note: after calling this function e from the input environment is no longer usable.

valuereplaceEnv

:: e :> es
=> EffectRep (DispatchOf e) e
The representation of the effect.
-> Relinker (EffectRep (DispatchOf e)) e
-> Env es
-> IO (Env es)

Replace a specific effect in the stack with a new value.

Note: unlike in putEnv the value in not changed in place, so only the new environment will see it.

valueunreplaceEnv :: e :> es => Env es -> IO ()

Remove a reference to the replaced effect.

Note: after calling this function the input environment is no longer usable.

valuesubsumeEnv :: e :> es => Env es -> IO (Env (e ': es))

Reference an existing effect from the top of the stack.

valueinjectEnv :: Subset xs es => Env es -> IO (Env xs)

Construct an environment containing a permutation (with possible duplicates) of a subset of effects from the input environment.

Data retrieval and update

valuegetEnv

:: e :> es
=> Env es
The environment.
-> IO (EffectRep (DispatchOf e) e)

Extract a specific data type from the environment.

valueputEnv

:: e :> es
=> Env es
The environment.
-> EffectRep (DispatchOf e) e
-> IO ()

Replace the data type in the environment with a new value (in place).

valuestateEnv

:: e :> es
=> Env es
The environment.
-> (EffectRep (DispatchOf e) e -> IO (a, EffectRep (DispatchOf e) e))
-> IO a

Modify the data type in the environment and return a value (in place).

valuemodifyEnv

:: e :> es
=> Env es
The environment.
-> (EffectRep (DispatchOf e) e -> IO (EffectRep (DispatchOf e) e))
-> IO ()

Modify the data type in the environment (in place).