gamnit: make `SpriteSet` public so clients can use its services

[nit.git] / lib / poset.nit

diff --git a/lib/poset.nit b/lib/poset.nit
index 98205ac..767b27d 100644 (file)
--- a/lib/poset.nit
+++ b/lib/poset.nit
@@ -729,3 +729,84 @@ class POSetElement[E]
                end
        end
 end
+
+redef class MapRead[K, V]
+       # Return all elements of `keys` that have a value.
+       #
+       # ~~~
+       # var map = new Map[String, String]
+       # map["A"] = "a"
+       # map["B"] = "b"
+       # map["C"] = "c"
+       #
+       # assert map.filter_keys(["B"]) == ["B"]
+       # assert map.filter_keys(["A", "Z", "C"]) == ["A", "C"]
+       # assert map.filter_keys(["X", "Y", "Z"]).is_empty
+       # ~~~
+       #
+       # `has_key` is used to filter.
+       fun filter_keys(keys: Collection[nullable Object]): Array[K]
+       do
+               var res = new Array[K]
+               for e in keys do
+                       if has_key(e) then res.add e
+               end
+               return res
+       end
+
+       # Search all the values in `pe.greaters`.
+       #
+       # Elements without values are ignored.
+       #
+       # Basically, values defined in all 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 HashMap[String, String]
+       # map["A"] = "a"
+       # map["C"] = "c"
+       # map["X"] = "x"
+       # map["E"] = "e"
+       #
+       # assert map.lookup_all_values(pos["B"]).has_exactly(["a"])
+       # assert map.lookup_all_values(pos["C"]).has_exactly(["a", "c"])
+       # assert map.lookup_all_values(pos["D"]).has_exactly(["a", "c", "x"])
+       # ~~~
+       fun lookup_all_values(pe: POSetElement[K]): Set[V]
+       do
+               var res = new Set[V]
+               for k in filter_keys(pe.greaters) do res.add self[k]
+               return res
+       end
+
+       # Combine 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 HashMap[String, String]
+       # map["A"] = "a"
+       # map["C"] = "c"
+       # map["X"] = "x"
+       # map["E"] = "e"
+       #
+       # assert map.lookup_values(pos["B"]).has_exactly(["a"])
+       # assert map.lookup_values(pos["C"]).has_exactly(["c"])
+       # assert map.lookup_values(pos["D"]).has_exactly(["c", "x"])
+       # ~~~
+       fun lookup_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 self[k]
+               return res
+       end
+end