lib/collection: improve documentation of `has_all`

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

diff --git a/lib/standard/collection/abstract_collection.nit b/lib/standard/collection/abstract_collection.nit
index 56633ce..9d79de9 100644 (file)
--- a/lib/standard/collection/abstract_collection.nit
+++ b/lib/standard/collection/abstract_collection.nit
@@ -123,12 +123,18 @@ interface Collection[E]
                return iterator.item
        end
 
-       # Is the collection contains all the elements of `other`?
+       # Does the collection contain at least each element of `other`?
        #
-       #    assert [1,1,1].has_all([1])         == true
-       #    assert [1,1,1].has_all([1,2])       == false
        #    assert [1,3,4,2].has_all([1..2])    == true
        #    assert [1,3,4,2].has_all([1..5])    == false
+       #
+       # Repeated elements in the collections are not considered.
+       #
+       #    assert [1,1,1].has_all([1])         == true
+       #    assert [1..5].has_all([1,1,1])      == true
+       #
+       # Note that the default implementation is general and correct for any lawful Collections.
+       # It is memory-efficient but relies on `has` so may be CPU-inefficient for some kind of collections.
        fun has_all(other: Collection[E]): Bool
        do
                for x in other do if not has(x) then return false