Data.DAWG

The module implements directed acyclic word graphs (DAWGs) internaly represented as minimal acyclic deterministic finite-state automata. The implementation provides fast insert and delete operations which can be used to build the DAWG structure incrementaly.

Transition backend has to be specified by a type signature. You can import the desired transition type and define your own dictionary construction function.

 import Data.DAWG
 import Data.DAWG.Trans.Map (Trans)

 mkDict :: (Enum a, Ord b) => [([a], b)] -> DAWG Trans a b
 mkDict = fromList

DAWG type

data DAWG t a b

A directed acyclic word graph with phantom type a representing type of alphabet elements.

Instances

(Show t, Show b) => Show (DAWG t a b)

(MkNode t b, Binary t, Binary b) => Binary (DAWG t a b)

class (Ord (Node t a), Trans t) => MkNode t a

Is t a valid transition map within the context of a-valued automata nodes? All transition implementations provided by the library are instances of this class.

Instances

(Ord (Node t a), Trans t) => MkNode t a

Query

numStates :: DAWG t a b -> Int

Number of states in the underlying graph.

lookup :: (Enum a, MkNode t b) => [a] -> DAWG t a b -> Maybe b

Find value associated with the key.

Construction

empty :: MkNode t b => DAWG t a b

Empty DAWG.

fromList :: (Enum a, MkNode t b) => [([a], b)] -> DAWG t a b

Construct DAWG from the list of (word, value) pairs.

fromListWith :: (Enum a, MkNode t b) => (b -> b -> b) -> [([a], b)] -> DAWG t a b

Construct DAWG from the list of (word, value) pairs with a combining function. The combining function is applied strictly.

fromLang :: (Enum a, MkNode t ()) => [[a]] -> DAWG t a ()

Make DAWG from the list of words. Annotate each word with the () value.

Insertion

insert :: (Enum a, MkNode t b) => [a] -> b -> DAWG t a b -> DAWG t a b

Insert the (key, value) pair into the DAWG.

insertWith :: (Enum a, MkNode t b) => (b -> b -> b) -> [a] -> b -> DAWG t a b -> DAWG t a b

Insert with a function, combining new value and old value. insertWith f key value d will insert the pair (key, value) into d if key does not exist in the DAWG. If the key does exist, the function will insert the pair (key, f new_value old_value).

Deletion

delete :: (Enum a, MkNode t b) => [a] -> DAWG t a b -> DAWG t a b

Delete the key from the DAWG.

Conversion

assocs :: (Enum a, MkNode t b) => DAWG t a b -> [([a], b)]

Return all key/value pairs in the DAWG in ascending key order.

keys :: (Enum a, MkNode t b) => DAWG t a b -> [[a]]

Return all keys of the DAWG in ascending order.

elems :: MkNode t b => DAWG t a b -> [b]

Return all elements of the DAWG in the ascending order of their keys.