Data.VectorClock

Vector clock type

data VectorClock a b

A vector clock is, conceptually, an associtive list sorted by the value of the key, where each key appears only once.

Instances

(Eq a, Eq b) => Eq (VectorClock a b)

(Show a, Show b) => Show (VectorClock a b)

(Binary a, Binary b) => Binary (VectorClock a b)

Construction

empty :: VectorClock a b

The empty vector clock.

singleton :: a -> b -> VectorClock a b

A vector clock with a single element.

fromList :: Ord a => [(a, b)] -> VectorClock a b

Insert each entry in the list one at a time.

Query

null :: VectorClock a b -> Bool

Is the vector clock empty?

size :: VectorClock a b -> Int

The number of entries in the vector clock.

member :: Ord a => a -> VectorClock a b -> Bool

Is the given key a key in an entry of the vector clock?

lookup :: Ord a => a -> VectorClock a b -> Maybe b

Lookup the value for a key in the vector clock.

Insertion

insert :: Ord a => a -> b -> VectorClock a b -> VectorClock a b

Insert or replace the entry for a key.

Deletion

delete :: Ord a => a -> VectorClock a b -> VectorClock a b

Delete an entry from the vector clock. If the requested entry does not exist, does nothing.

Merges

combine :: (Ord a, Ord b) => (a -> Maybe b -> Maybe b -> Maybe b) -> VectorClock a b -> VectorClock a b -> VectorClock a b

Combine two vector clocks entry-by-entry.

max :: (Ord a, Ord b) => VectorClock a b -> VectorClock a b -> VectorClock a b

The maximum of the two vector clocks.

Relations

data Relation

The relations two vector clocks may find themselves in.

Constructors

Causes

CausedBy

Concurrent

Instances

Eq Relation

Show Relation

relation :: (Ord a, Ord b) => VectorClock a b -> VectorClock a b -> Relation

The relation between the two vector clocks.

Debugging

valid :: (Ord a, Ord b) => VectorClock a b -> Bool

Check whether the vector clock is valid or not.