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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 8fef28d · 2026-11-02

Modulepolysemy-kvstore-0.1.3.0Haskell2010

Polysemy.KVStore

Contents

Effect
Actions
Interpreters

Synopsis

data KVStore
value lookupKV
value lookupOrThrowKV
value existsKV
value writeKV
value deleteKV
value updateKV
value modifyKV
value runKVStoreAsState
value runKVStorePure
value runKVStoreAsKVStore
value runKVStoreAsKVStoreSem

Packagepolysemy-kvstore-0.1.3.0
Exports12
LanguageHaskell2010
LicenceMIT
SourceKVStore.hs

Effect

datadata KVStore k v (m :: Type -> Type) a where

Models things like Redis, HTTP GET/POST, etc. Things that are keyed, have a value, and may or may not be there.

Constructors

LookupKV :: k -> KVStore k v m (Maybe v)
UpdateKV :: k -> Maybe v -> KVStore k v m ()

Actions

valuelookupKV :: Member (KVStore k v) r => k -> Sem r (Maybe v)

valuelookupOrThrowKV

:: Members '[KVStore k v, Error e] r
=> k -> e
-> k
-> Sem r v

valueexistsKV :: Member (KVStore k v) r => k -> Sem r Bool

valuewriteKV :: Member (KVStore k v) r => k -> v -> Sem r ()

valuedeleteKV :: Member (KVStore k v) r => k -> Sem r ()

valueupdateKV :: Member (KVStore k v) r => k -> Maybe v -> Sem r ()

valuemodifyKV

:: Member (KVStore k v) r
=> v
Default value if the key isn't present
-> (v -> v)
-> k
-> Sem r ()

Interpreters

valuerunKVStoreAsState

:: Ord k
=> Sem (KVStore k v ': r) a
-> Sem (State (Map k v) ': r) a

Run a KVStore as a State effect containing a Map.

valuerunKVStorePure

:: Ord k
=> Map k v
-> Sem (KVStore k v ': r) a
-> Sem r (Map k v, a)

Run a KVStore purely as a Map.

valuerunKVStoreAsKVStore

:: (k -> k')
A function to transform the key into the interpreted key.
-> (v -> v')
A function to transform the value into the interpreted value.
-> (v' -> v)
A function to transform the interpreted key back into the current value.
-> Sem (KVStore k v ': r) a
-> Sem (KVStore k' v' ': r) a

Run a KVStore in terms of another KVStore by way of pure key and value transformations.

valuerunKVStoreAsKVStoreSem

:: Members '[KVStore k' v'] r
=> (k -> Sem r k')
A function to transform the key into the interpreted key.
-> (v -> Sem r v')
A function to transform the value into the interpreted value.
-> (v' -> Sem r v)
A function to transform the interpreted value back into the current value.
-> Sem (KVStore k v ': r) a
-> Sem r a

Run a KVStore in terms of another KVStore by way of transforming the keys and values with Sem functions.