Safe Haskell	None
Language	Haskell2010

Control.Monad.Memoize

Synopsis

class Monad m => MonadMemoize m where
- memoizeOn :: forall a p. (Ord a, Typeable a, Typeable p) => Name -> a -> m p -> m p
memoize :: (MonadMemoize m, Ord a, Typeable a, Typeable p) => Name -> (a -> m p) -> a -> m p
newtype MemoizeT m a = MemoizeT {
- unMemoizeT :: StateT (DMap MemoizationKey Identity) m a
}
runMemoizeT :: forall m a. Monad m => MemoizeT m a -> m a
data MemoizationKey (t :: Type) where
- MemoizationKey :: (Ord a, Typeable a, Typeable p) => Name -> a -> MemoizationKey p

Documentation

class Monad m => MonadMemoize m where Source #

Methods

memoizeOn Source #

Arguments

:: forall a p. (Ord a, Typeable a, Typeable p)
=> Name	A unique name used to identify the function being memoized. There isn’t really any metaprogramming going on here, we just use a Template Haskell `Name` as a convenient source for a static, unique identifier.
-> a	The value to use as the memoization key. It’s the caller’s responsibility to ensure multiple calls to the same function don’t use the same key.
-> m p
-> m p

Memoizes a parser constructor function for the extent of a single schema construction process. This is mostly useful for recursive parsers; see Note [Tying the knot] for more details.

The generality of the type here allows us to use this with multiple concrete parser types:

memoizeOn :: (MonadMemoize m, MonadParse n) => Name -> a -> m (Parser n b) -> m (Parser n b)
memoizeOn :: (MonadMemoize m, MonadParse n) => Name -> a -> m (FieldParser n b) -> m (FieldParser n b)

Instances

Instances details

MonadIO m => MonadMemoize (MemoizeT m) Source #	see Note [MemoizeT requires MonadIO]
Instance details Defined in Control.Monad.Memoize Methods memoizeOn :: (Ord a, Typeable a, Typeable p) => Name -> a -> MemoizeT m p -> MemoizeT m p Source #
MonadMemoize m => MonadMemoize (ReaderT a m) Source #
Instance details Defined in Control.Monad.Memoize Methods memoizeOn :: (Ord a0, Typeable a0, Typeable p) => Name -> a0 -> ReaderT a m p -> ReaderT a m p Source #

memoize :: (MonadMemoize m, Ord a, Typeable a, Typeable p) => Name -> (a -> m p) -> a -> m p Source #

A wrapper around memoizeOn that memoizes a function by using its argument as the key.

newtype MemoizeT m a Source #

Constructors

MemoizeT
Fields unMemoizeT :: StateT (DMap MemoizationKey Identity) m a

Instances

Instances details

MonadReader r m => MonadReader r (MemoizeT m) Source #
Instance details Defined in Control.Monad.Memoize Methods ask :: MemoizeT m r # local :: (r -> r) -> MemoizeT m a -> MemoizeT m a # reader :: (r -> a) -> MemoizeT m a #
MonadError e m => MonadError e (MemoizeT m) Source #
Instance details Defined in Control.Monad.Memoize Methods throwError :: e -> MemoizeT m a # catchError :: MemoizeT m a -> (e -> MemoizeT m a) -> MemoizeT m a #
Monad m => Monad (MemoizeT m) Source #
Instance details Defined in Control.Monad.Memoize Methods (>>=) :: MemoizeT m a -> (a -> MemoizeT m b) -> MemoizeT m b # (>>) :: MemoizeT m a -> MemoizeT m b -> MemoizeT m b # return :: a -> MemoizeT m a #
Functor m => Functor (MemoizeT m) Source #
Instance details Defined in Control.Monad.Memoize Methods fmap :: (a -> b) -> MemoizeT m a -> MemoizeT m b # (<$) :: a -> MemoizeT m b -> MemoizeT m a #
Monad m => Applicative (MemoizeT m) Source #
Instance details Defined in Control.Monad.Memoize Methods pure :: a -> MemoizeT m a # (<>) :: MemoizeT m (a -> b) -> MemoizeT m a -> MemoizeT m b # liftA2 :: (a -> b -> c) -> MemoizeT m a -> MemoizeT m b -> MemoizeT m c # (>) :: MemoizeT m a -> MemoizeT m b -> MemoizeT m b # (<*) :: MemoizeT m a -> MemoizeT m b -> MemoizeT m a #
MonadIO m => MonadMemoize (MemoizeT m) Source #	see Note [MemoizeT requires MonadIO]
Instance details Defined in Control.Monad.Memoize Methods memoizeOn :: (Ord a, Typeable a, Typeable p) => Name -> a -> MemoizeT m p -> MemoizeT m p Source #

runMemoizeT :: forall m a. Monad m => MemoizeT m a -> m a Source #

data MemoizationKey (t :: Type) where Source #

A key used to distinguish calls to memoized functions. The Name distinguishes calls to completely different parsers, and the a value records the arguments.

Constructors

MemoizationKey :: (Ord a, Typeable a, Typeable p) => Name -> a -> MemoizationKey p