Data.Refcount

Documentation

newtype Refcount a

Maintain a collection of objects with duplication counts.

Constructors

Refcount

Fields

unRefcount :: HashMap a Int

Instances

Eq a => Eq (Refcount a)

Show a => Show (Refcount a)

Generic (Refcount a)

(Arbitrary a, Hashable a, Eq a) => Arbitrary (Refcount a)

(Hashable a, Eq a) => Monoid (Refcount a)

refcount :: (Hashable a, Eq a) => a -> Refcount a -> Int

Lookup the count of an object.

refcounts :: Refcount a -> [(a, Int)]

Retrieve objects and their counts.

refcounted :: Refcount a -> [a]

Retrieve the refcounted objects.

insertRef :: (Hashable a, Eq a) => a -> Refcount a -> Refcount a

Insert an object and increment its count.

deleteRef :: (Hashable a, Eq a) => a -> Refcount a -> Maybe (Refcount a)

Remove a reference to an element and decrease its count, possibly removing it from the set. Returns Nothing if the element wasn't found, or Just set.

removeRef :: (Hashable a, Eq a) => a -> Refcount a -> Maybe (Bool, Refcount a)

Remove a reference to an element and decrease its count, possibly removing it from the set. Returns Nothing if the element wasn't found, or Just (wasRemoved, set).

fromList :: (Hashable a, Eq a) => [a] -> Refcount a

Create a counted structure from a list of elements.