lib/core/collection: improve the default `has_all` for basic cases

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

diff --git a/lib/core/collection/abstract_collection.nit b/lib/core/collection/abstract_collection.nit
index 5f9af05..e17ecfa 100644 (file)
--- a/lib/core/collection/abstract_collection.nit
+++ b/lib/core/collection/abstract_collection.nit
@@ -149,6 +149,12 @@ interface Collection[E]
        # It is memory-efficient but relies on `has` so may be CPU-inefficient for some kind of collections.
        fun has_all(other: Collection[nullable Object]): Bool
        do
+               if is_same_instance(other) then return true
+               var ol = other.length
+               var  l = length
+               if ol == 0 then return true
+               if l == 0 then return false
+               if ol == 1 then return has(other.first)
                for x in other do if not has(x) then return false
                return true
        end