Ajout de memq.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@277 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/list.ml

@@ -95,6 +95,10 @@ let rec mem x = function
     [] -> false
   | a::l -> a = x or mem x l
 
+let rec memq x = function
+    [] -> false
+  | a::l -> a == x or mem x l
+
 let rec assoc x = function
     [] -> raise Not_found
   | (a,b)::l -> if a = x then b else assoc x l

stdlib/list.mli

@@ -83,6 +83,9 @@ val exists : ('a -> bool) -> 'a list -> bool
 val mem : 'a -> 'a list -> bool
         (* [mem a l] is true if and only if [a] is equal
            to an element of [l]. *)
+val memq : 'a -> 'a list -> bool
+        (* Same as [mem], but uses physical equality instead of structural
+           equality to compare list elements. *)
 
 (** Association lists *)
 
@@ -97,7 +100,7 @@ val mem_assoc : 'a -> ('a * 'b) list -> bool
         (* Same as [assoc], but simply return true if a binding exists,
            and false if no bindings exist for the given key. *)
 val assq : 'a -> ('a * 'b) list -> 'b
-        (* Same as [assoc], but use physical equality instead of structural
+        (* Same as [assoc], but uses physical equality instead of structural
            equality to compare keys. *)
 
 (** Lists of pairs *)