Moduleequivalence-0.4.1Haskell2010

Data.Equivalence.Monad

This is an alternative interface to the union-find implementation in 'Data.Equivalence.STT'. It is wrapped into the monad transformer EquivT.

4 types
1 class
4 values

Packageequivalence-0.4.1
Exports9
LanguageHaskell2010
LicenceBSD-3-Clause
SourceMonad.hs

classclass (Monad m, Applicative m, Ord v) => MonadEquiv c v d (m :: Type -> Type) | m -> v, m -> c, m -> d where

This class specifies the interface for a monadic computation that maintains an equivalence relation.

Methods

equivalent :: v -> v -> m Bool
This function decides whether the two given elements are equivalent in the current equivalence relation.
classDesc :: v -> m d
This function obtains the descriptor of the given element's equivalence class.
equateAll :: [v] -> m ()
This function equates the element in the given list. That is, it unions the equivalence classes of the elements and combines their descriptor.
equate :: v -> v -> m ()
This function equates the given two elements. That is it unions the equivalence classes of the two elements.
removeClass :: v -> m Bool
This function removes the equivalence class of the given element. If there is no corresponding equivalence class, False is returned; otherwise True.
getClass :: v -> m c
This function provides the equivalence class of the given element.
combineAll :: [c] -> m ()
This function combines all equivalence classes in the given list. Afterwards all elements in the argument list represent the same equivalence class!
combine :: c -> c -> m c
This function combines the two given equivalence classes. Afterwards both arguments represent the same equivalence class! One of it is returned in order to represent the new combined equivalence class.
(===) :: c -> c -> m Bool
This function decides whether the two given equivalence classes are the same.
desc :: c -> m d
This function returns the descriptor of the given equivalence class.
remove :: c -> m Bool
This function removes the given equivalence class. If the equivalence class does not exist anymore, False is returned; otherwise True.
values :: m [v]
This function returns all values represented by some equivalence class.
classes :: m [c]
This function returns the list of all equivalence classes.

Instances5MonadEquiv

MonadEquiv c v d m => MonadEquiv c v d (ExceptT e m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadEquiv c v d m => MonadEquiv c v d (ReaderT r m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadEquiv c v d m => MonadEquiv c v d (StateT s m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
(MonadEquiv c v d m, Monoid w) => MonadEquiv c v d (WriterT w m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
(Monad m, Applicative m, Ord v) => MonadEquiv (Class s d v) v d (EquivT s d v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad

newtypenewtype EquivT s c v (m :: Type -> Type) a

This monad transformer encapsulates computations maintaining an equivalence relation. A monadic computation of type EquivT s c v m a maintains a state space indexed by type s, maintains an equivalence relation over elements of type v with equivalence class descriptors of type c and contains an internal monadic computation of type m a.

Constructors

EquivT
- unEquivT :: ReaderT (Equiv s c v) (STT s m) a

Instances10MonadError, MonadReader, MonadState, MonadWriter, MonadTrans, MonadEquiv, …

MonadError e m => MonadError e (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadReader r m => MonadReader r (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadState st m => MonadState st (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadWriter w m => MonadWriter w (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
MonadTrans (EquivT s c v)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
(Monad m, Applicative m, Ord v) => MonadEquiv (Class s d v) v d (EquivT s d v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
Monad m => Monad (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
Functor m => Functor (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
Monad m => MonadFail (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad
Monad m => Applicative (EquivT s c v m)Defined in equivalence-0.4.1 · Data.Equivalence.Monad

typetype EquivT' s = EquivT s ()

This monad transformer is a special case of EquivT that only maintains trivial equivalence class descriptors of type ().

typetype EquivM s c v = EquivT s c v Identity

This monad encapsulates computations maintaining an equivalence relation. A monadic computation of type EquivM s c v a maintains a state space indexed by type s, maintains an equivalence relation over elements of type v with equivalence class descriptors of type c and returns a value of type a.

typetype EquivM' s v = EquivM s () v

This monad is a special case of EquivM that only maintains trivial equivalence class descriptors of type ().

valuerunEquivT

:: (Monad m, Applicative m)
=> (v -> c)
Used to construct an equivalence class descriptor for a singleton class.
-> (c -> c -> c)
Used to combine the equivalence class descriptor of two classes which are meant to be combined.
-> (forall s. EquivT s c v m a)
-> m a

This function runs a monadic computation that maintains an equivalence relation. The first two arguments specify how to construct an equivalence class descriptor for a singleton class and how to combine two equivalence class descriptors.

valuerunEquivT' :: (Monad m, Applicative m) => (forall s. EquivT' s v m a) -> m a

This function is a special case of runEquivT that only maintains trivial equivalence class descriptors of type ().

valuerunEquivM

:: (v -> c)
Used to construct an equivalence class descriptor for a singleton class.
-> (c -> c -> c)
Used to combine the equivalence class descriptor of two classes which are meant to be combined.
-> (forall s. EquivM s c v a)
-> a

This function runs a monadic computation that maintains an equivalence relation. The first tow arguments specify how to construct an equivalence class descriptor for a singleton class and how to combine two equivalence class descriptors.

valuerunEquivM' :: (forall s. EquivM' s v a) -> a

This function is a special case of runEquivM that only maintains trivial equivalence class descriptors of type ().