insertWith package:dependent-map

O(log n). Insert with a function, combining new value and old value. insertWith f key value mp will insert the entry key :=> value into mp if key does not exist in the map. If the key does exist, the function will insert the entry key :=> f new_value old_value.

Same as insertWith, but the combining function is applied strictly. This is often the most desirable behavior.

O(log n). Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the entry key :=> value into mp if key does not exist in the map. If the key does exist, the function will insert the entry key :=> f key new_value old_value. Note that the key passed to f is the same key passed to insertWithKey.

Same as insertWithKey, but the combining function is applied strictly.