Safe Haskell	Safe-Inferred
Language	Haskell2010

Effectful.Internal.Unlift

Contents

Unlifting strategies
Unlifting functions

Description

Implementation of sequential and concurrent unlifts.

This module is intended for internal use only, and may change without warning in subsequent releases.

Synopsis

data UnliftStrategy
- = SeqUnlift
- | ConcUnlift !Persistence !Limit
data Persistence
- = Ephemeral
- | Persistent
data Limit
- = Limited !Int
- | Unlimited
seqUnlift :: HasCallStack => ((forall r. m r -> IO r) -> IO a) -> Env es -> (forall r. m r -> Env es -> IO r) -> IO a
concUnlift :: HasCallStack => Persistence -> Limit -> ((forall r. m r -> IO r) -> IO a) -> Env es -> (forall r. m r -> Env es -> IO r) -> IO a

Unlifting strategies

data UnliftStrategy Source #

The strategy to use when unlifting Eff computations via withEffToIO or the localUnlift family.

Constructors

SeqUnlift	The sequential strategy is the fastest and a default setting for `IOE`. Any attempt of calling the unlifting function in threads distinct from its creator will result in a runtime error.
ConcUnlift !Persistence !Limit	The concurrent strategy makes it possible for the unlifting function to be called in threads distinct from its creator. See `Persistence` and `Limit` settings for more information.

Instances

Instances details

Generic UnliftStrategy Source #
Instance details Defined in Effectful.Internal.Unlift Associated Types type Rep UnliftStrategy :: Type -> Type # Methods from :: UnliftStrategy -> Rep UnliftStrategy x # to :: Rep UnliftStrategy x -> UnliftStrategy #
Show UnliftStrategy Source #
Instance details Defined in Effectful.Internal.Unlift Methods showsPrec :: Int -> UnliftStrategy -> ShowS # show :: UnliftStrategy -> String # showList :: [UnliftStrategy] -> ShowS #
Eq UnliftStrategy Source #
Instance details Defined in Effectful.Internal.Unlift Methods (==) :: UnliftStrategy -> UnliftStrategy -> Bool # (/=) :: UnliftStrategy -> UnliftStrategy -> Bool #
Ord UnliftStrategy Source #
Instance details Defined in Effectful.Internal.Unlift Methods compare :: UnliftStrategy -> UnliftStrategy -> Ordering # (<) :: UnliftStrategy -> UnliftStrategy -> Bool # (<=) :: UnliftStrategy -> UnliftStrategy -> Bool # (>) :: UnliftStrategy -> UnliftStrategy -> Bool # (>=) :: UnliftStrategy -> UnliftStrategy -> Bool # max :: UnliftStrategy -> UnliftStrategy -> UnliftStrategy # min :: UnliftStrategy -> UnliftStrategy -> UnliftStrategy #
type Rep UnliftStrategy Source #
Instance details Defined in Effectful.Internal.Unlift type Rep UnliftStrategy = D1 ('MetaData "UnliftStrategy" "Effectful.Internal.Unlift" "effectful-core-2.3.1.0-EGxNgHuMuzT2IPf2MGZbuo" 'False) (C1 ('MetaCons "SeqUnlift" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ConcUnlift" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Persistence) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Limit)))

data Persistence Source #

Persistence setting for the ConcUnlift strategy.

Different functions require different persistence strategies. Examples:

Lifting pooledMapConcurrentlyN from the unliftio library requires the Ephemeral strategy as we don't want jobs to share environment changes made by previous jobs run in the same worker thread.
Lifting forkIOWithUnmask requires the Persistent strategy, otherwise the unmasking function would start with a fresh environment each time it's called.

Constructors

Ephemeral	Don't persist the environment between calls to the unlifting function in threads distinct from its creator.
Persistent	Persist the environment between calls to the unlifting function within a particular thread.

Instances

Instances details

Generic Persistence Source #
Instance details Defined in Effectful.Internal.Unlift Associated Types type Rep Persistence :: Type -> Type # Methods from :: Persistence -> Rep Persistence x # to :: Rep Persistence x -> Persistence #
Show Persistence Source #
Instance details Defined in Effectful.Internal.Unlift Methods showsPrec :: Int -> Persistence -> ShowS # show :: Persistence -> String # showList :: [Persistence] -> ShowS #
Eq Persistence Source #
Instance details Defined in Effectful.Internal.Unlift Methods (==) :: Persistence -> Persistence -> Bool # (/=) :: Persistence -> Persistence -> Bool #
Ord Persistence Source #
Instance details Defined in Effectful.Internal.Unlift Methods compare :: Persistence -> Persistence -> Ordering # (<) :: Persistence -> Persistence -> Bool # (<=) :: Persistence -> Persistence -> Bool # (>) :: Persistence -> Persistence -> Bool # (>=) :: Persistence -> Persistence -> Bool # max :: Persistence -> Persistence -> Persistence # min :: Persistence -> Persistence -> Persistence #
type Rep Persistence Source #
Instance details Defined in Effectful.Internal.Unlift type Rep Persistence = D1 ('MetaData "Persistence" "Effectful.Internal.Unlift" "effectful-core-2.3.1.0-EGxNgHuMuzT2IPf2MGZbuo" 'False) (C1 ('MetaCons "Ephemeral" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Persistent" 'PrefixI 'False) (U1 :: Type -> Type))

data Limit Source #

Limit setting for the ConcUnlift strategy.

Constructors

Limited !Int

Behavior dependent on the Persistence setting.

For Ephemeral, it limits the amount of uses of the unlifting function in threads distinct from its creator to N. The unlifting function will create N copies of the environment when called N times and K+1 copies when called K < N times.

For Persistent, it limits the amount of threads, distinct from the creator of the unlifting function, it can be called in to N. The amount of calls to the unlifting function within a particular threads is unlimited. The unlifting function will create N copies of the environment when called in N threads and K+1 copies when called in K < N threads.

Unlimited

Unlimited use of the unlifting function.

Instances

Instances details

Generic Limit Source #
Instance details Defined in Effectful.Internal.Unlift Associated Types type Rep Limit :: Type -> Type # Methods from :: Limit -> Rep Limit x # to :: Rep Limit x -> Limit #
Show Limit Source #
Instance details Defined in Effectful.Internal.Unlift Methods showsPrec :: Int -> Limit -> ShowS # show :: Limit -> String # showList :: [Limit] -> ShowS #
Eq Limit Source #
Instance details Defined in Effectful.Internal.Unlift Methods (==) :: Limit -> Limit -> Bool # (/=) :: Limit -> Limit -> Bool #
Ord Limit Source #
Instance details Defined in Effectful.Internal.Unlift Methods compare :: Limit -> Limit -> Ordering # (<) :: Limit -> Limit -> Bool # (<=) :: Limit -> Limit -> Bool # (>) :: Limit -> Limit -> Bool # (>=) :: Limit -> Limit -> Bool # max :: Limit -> Limit -> Limit # min :: Limit -> Limit -> Limit #
type Rep Limit Source #
Instance details Defined in Effectful.Internal.Unlift type Rep Limit = D1 ('MetaData "Limit" "Effectful.Internal.Unlift" "effectful-core-2.3.1.0-EGxNgHuMuzT2IPf2MGZbuo" 'False) (C1 ('MetaCons "Limited" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Int)) :+: C1 ('MetaCons "Unlimited" 'PrefixI 'False) (U1 :: Type -> Type))

Unlifting functions

seqUnlift :: HasCallStack => ((forall r. m r -> IO r) -> IO a) -> Env es -> (forall r. m r -> Env es -> IO r) -> IO a Source #

Sequential unlift.

concUnlift :: HasCallStack => Persistence -> Limit -> ((forall r. m r -> IO r) -> IO a) -> Env es -> (forall r. m r -> Env es -> IO r) -> IO a Source #

Concurrent unlift.