# limitations under the License.
# Highly specific, but useful, collections-related classes.
-module more_collections
+module more_collections is serialize
+
+import serialization
+import poset
# Simple way to store an `HashMap[K, Array[V]]`
#
super HashMap[K, Array[V]]
# Add `v` to the array associated with `k`.
+ #
# If there is no array associated, then create it.
+ #
+ # For the inverse operation, see `remove_one`.
+ #
+ # ```
+ # var m = new MultiHashMap[String, Char]
+ # m.add_one("four", 'i')
+ # m.add_one("four", 'i')
+ # m.add_one("four", 'i')
+ # m.add_one("four", 'i')
+ # assert m.has_key("four")
+ # assert m["four"] == ['i', 'i', 'i', 'i']
+ # ```
fun add_one(k: K, v: V)
do
var x = self.get_or_null(k)
self[key] = res
return res
end
+
+ # Remove an occurrence of `v` from the array associated with `k`.
+ #
+ # If the associated array does not contain `v`, do nothing. If the
+ # associated array only contain one element and this element is `v`, remove
+ # the key `k`.
+ #
+ # In a nutshell, does the inverse operation of `add_one`.
+ #
+ # ```
+ # var m = new MultiHashMap[String, Char]
+ # m["four"] = ['4', 'i', 'i', 'i', 'i']
+ # m.remove_one("four", 'i')
+ # assert m["four"] == ['4', 'i', 'i', 'i']
+ #
+ # m = new MultiHashMap[String, Char]
+ # m.add_one("one", '1')
+ # m.remove_one("one", '?')
+ # assert m["one"] == ['1']
+ # m.remove_one("one", '1')
+ # assert not m.has_key("one")
+ # assert m["one"] == new Array[Char]
+ #
+ # m = new MultiHashMap[String, Char]
+ # m.add_one("one", '1')
+ # m.remove_one("two", '2')
+ # assert not m.has_key("two")
+ # assert m["one"] == ['1']
+ # assert m["two"] == new Array[Char]
+ # ```
+ fun remove_one(k: K, v: V)
+ do
+ var x = get_or_null(k)
+ if x != null then
+ x.remove(v)
+ if x.is_empty then keys.remove(k)
+ end
+ end
+
+ # Search the values in `pe.greaters` from the most smaller elements that have a value.
+ #
+ # Elements without values are ignored.
+ #
+ # Basically, values defined in nearest greater elements of `pe` are inherited.
+ #
+ # ~~~
+ # var pos = new POSet[String]
+ # pos.add_chain(["E", "D", "C", "B", "A"])
+ # pos.add_chain(["D", "X", "B"])
+ #
+ # var map = new MultiHashMap[String, String]
+ # map["A"].append(["a", "1"])
+ # map["C"].append(["c", "2"])
+ # map["X"].append(["x", "2"])
+ # map["E"].add "e"
+ #
+ # assert map.lookup_joined_values(pos["B"]).has_exactly(["a", "1"])
+ # assert map.lookup_joined_values(pos["C"]).has_exactly(["c", "2"])
+ # assert map.lookup_joined_values(pos["D"]).has_exactly(["c", "x", "2"])
+ # ~~~
+ fun lookup_joined_values(pe: POSetElement[K]): Set[V]
+ do
+ var res = new Set[V]
+ for k in pe.poset.select_smallest(filter_keys(pe.greaters)) do res.add_all self[k]
+ return res
+
+ end
end
# Simple way to store an `HashMap[K1, HashMap[K2, V]]`
# assert hm2[2, "not-two"] == null
# ~~~~
class HashMap2[K1, K2, V]
+
private var level1 = new HashMap[K1, HashMap[K2, V]]
# Return the value associated to the keys `k1` and `k2`.
level2.keys.remove(k2)
end
+ # Is there a value at `k1, k2`?
+ fun has(k1: K1, k2: K2): Bool
+ do
+ if not level1.keys.has(k1) then return false
+ return level1[k1].keys.has(k2)
+ end
+
# Remove all items
fun clear do level1.clear
end
# assert hm3[2, "not-two", 22] == null
# ~~~~
class HashMap3[K1, K2, K3, V]
+
private var level1 = new HashMap[K1, HashMap2[K2, K3, V]]
# Return the value associated to the keys `k1`, `k2`, and `k3`.
level2.remove_at(k2, k3)
end
+ # Is there a value at `k1, k2, k3`?
+ fun has(k1: K1, k2: K2, k3: K3): Bool
+ do
+ if not level1.keys.has(k1) then return false
+ return level1[k1].has(k2, k3)
+ end
+
+ # Remove all items
+ fun clear do level1.clear
+end
+
+# Simple way to store an `HashMap[K1, HashMap[K2, HashMap[K3, HashMap[K4, V]]]]`
+#
+# ~~~~
+# var hm4 = new HashMap4[Int, String, Int, String, Float]
+# hm4[1, "one", 11, "un"] = 1.0
+# hm4[2, "two", 22, "deux"] = 2.0
+# assert hm4[1, "one", 11, "un"] == 1.0
+# assert hm4[2, "not-two", 22, "deux"] == null
+# ~~~~
+class HashMap4[K1, K2, K3, K4, V]
+
+ private var level1 = new HashMap[K1, HashMap3[K2, K3, K4, V]]
+
+ # Return the value associated to the keys `k1`, `k2`, `k3` and `k4`.
+ # Return `null` if no such a value.
+ fun [](k1: K1, k2: K2, k3: K3, k4: K4): nullable V
+ do
+ var level1 = self.level1
+ var level2 = level1.get_or_null(k1)
+ if level2 == null then return null
+ return level2[k2, k3, k4]
+ end
+
+ # Set `v` the value associated to the keys `k1`, `k2`, `k3` and `k4`.
+ fun []=(k1: K1, k2: K2, k3: K3, k4: K4, v: V)
+ do
+ var level1 = self.level1
+ var level2 = level1.get_or_null(k1)
+ if level2 == null then
+ level2 = new HashMap3[K2, K3, K4, V]
+ level1[k1] = level2
+ end
+ level2[k2, k3, k4] = v
+ end
+
+ # Remove the item at `k1`, `k2`, `k3` and `k4`
+ fun remove_at(k1: K1, k2: K2, k3: K3, k4: K4)
+ do
+ var level1 = self.level1
+ var level2 = level1.get_or_null(k1)
+ if level2 == null then return
+ level2.remove_at(k2, k3, k4)
+ end
+
+ # Is there a value at `k1, k2, k3, k4`?
+ fun has(k1: K1, k2: K2, k3: K3, k4: K4): Bool
+ do
+ if not level1.keys.has(k1) then return false
+ return level1[k1].has(k2, k3, k4)
+ end
+
# Remove all items
fun clear do level1.clear
end
end
end
end
+
+# 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
nitlanguage / nit.git / blobdiff