lib/sorter: add `MapRead::values_sorted_by_key`

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/standard/collection/sorter.nit b/lib/standard/collection/sorter.nit
index cfcc376..190f30a 100644 (file)
--- a/lib/standard/collection/sorter.nit
+++ b/lib/standard/collection/sorter.nit
@@ -250,6 +250,25 @@ interface Comparator
 
 end
 
+redef class MapRead[K,V]
+       # Return an array of all values sorted with their keys using `comparator`.
+       #
+       # ~~~
+       # var map = new HashMap[Int, String]
+       # map[10] = "ten"
+       # map[2]  = "two"
+       # map[1]  = "one"
+       # assert map.values_sorted_by_key(default_comparator) == ["one", "two", "ten"]
+       # assert map.values_sorted_by_key(alpha_comparator) == ["one", "ten", "two"]
+       # ~~~
+       fun values_sorted_by_key(comparator: Comparator): Array[V]
+       do
+               var keys = self.keys.to_a
+               comparator.sort(keys)
+               return [for k in keys do self[k]]
+       end
+end
+
 # This comparator uses the operator `<=>` to compare objects.
 # see `default_comparator` for an easy-to-use general stateless default comparator.
 class DefaultComparator