('k, 'v) Lookup.t provides a way to lookup keys in a map which uses symmetric diffs to trigger updates of the lookups.
The complexity of an update depends on:
n: the number of keys in the larger of the old/updated input mapk: the number of lookup nodes created using findm: the number of elements in the symdiff of the mapssymdiff(n): the cost of performing the symdiff on the map (m <= symdiff(n) <= n)Each update should cost O(symdiff(n) + m * log k), so this will be efficient when there are a lot of lookups (close to n) into a map which can be efficiently symdiffed (and therefore has a small number of changes also). The cost of updating when performing the same lookups by means of Incr.map ~f:(fun m -> Map.find m key) is O(k * log n).
val create :
?instrumentation:Instrumentation.t ->
?data_equal:('v -> 'v -> bool) ->
(('k, 'v, 'cmp) Core.Map.t, 'w) Incremental.t ->
comparator:('k, 'cmp) Core.Comparator.t ->
('k, 'v, 'cmp, 'w) tCreate the lookup structure on an incremental map.
val find : ('k, 'v, _, 'w) t -> 'k -> ('v option, 'w) Incremental.tCreate a node which performs Map.find on the input map.
find (create incr_map) key should be equivalent to Incr.map ~f:(fun m ->
Map.find m key) incr_map, but when you call find many times for a single create the nodes should update more efficiently in stabilisation when incr_map changes in a way which can be efficiently diffed.
This will re-use existing nodes when it can, but will not always do so.
module For_debug : sig ... end