# Keep track of the best elements according to a distance value.
#
# ~~~
# var bests = new BestDistance[String](5)
# bests.update(10, "Too big")
# assert bests.best_items.is_empty
# bests.update(5, "Just fine")
# bests.update(5, "Another one")
# assert bests.best_items.has_exactly(["Just fine", "Another one"])
# bests.update(2, "A better one")
# bests.update(4, "Not good enough")
# assert bests.best_distance == 2
# assert bests.best_items.has_exactly(["A better one"])
# ~~~
class BestDistance[E]
# Current smallest distance
var best_distance: Int is writable
# Known elements with the smallest distance
var best_items = new Set[E] is writable
# Register a `candidate` with a `distance`
#
# * To high, it is ignored.
# * Equal to the current best, it is added
# * Better that them, is is the new best element
#
# Return `true` if the candidate is kept (alone or with other)
# returns `false` if the candidate is ignored.
fun update(distance: Int, candidate: E): Bool
do
if distance > best_distance then return false
if distance < best_distance then
best_distance = distance
best_items.clear
end
best_items.add candidate
return true
end
end
lib/more_collections/more_collections.nit:680,1--719,3