Janiczek / elm-finger-tree

Finger Tree data structure and collections based on it (random-access array, deque, priority queue, interval map, ordered seq)

elm-finger-tree

Finger tree is a persistent data structure suitable for implementation of efficient deques, random access arrays, priority queues etc in pure immutable settings.

Thus, it's eg. a way to have deques in Elm that can be efficiently appended to from both sides, as a possible List replacement.