add find_map{,i} as better alias to existing functions

src/Sequence.ml

@@ -699,7 +699,7 @@ let mem ?(eq=(=)) x seq = exists (eq x) seq
 
 exception ExitFind
 
-let find f seq =
+let find_map f seq =
   let r = ref None in
   begin
     try
@@ -711,7 +711,9 @@ let find f seq =
   end;
   !r
 
-let findi f seq =
+let find = find_map
+
+let find_mapi f seq =
   let i = ref 0 in
   let r = ref None in
   begin
@@ -724,7 +726,9 @@ let findi f seq =
   end;
   !r
 
-let find_pred f seq = find (fun x -> if f x then Some x else None) seq
+let findi = find_mapi
+
+let find_pred f seq = find_map (fun x -> if f x then Some x else None) seq
 
 let find_pred_exn f seq = match find_pred f seq with
   | Some x -> x

src/Sequence.mli

@@ -144,10 +144,18 @@ val find : ('a -> 'b option) -> 'a t -> 'b option
 (** Find the first element on which the function doesn't return [None]
     @since 0.5 *)
 
+val find_map : ('a -> 'b option) -> 'a t -> 'b option
+(** Alias to {!find}
+    @since NEXT_RELEASE *)
+
 val findi : (int -> 'a -> 'b option) -> 'a t -> 'b option
 (** Indexed version of {!find}
     @since 0.9 *)
 
+val find_mapi : (int -> 'a -> 'b option) -> 'a t -> 'b option
+(** Alias to {!findi}
+    @since NEXT_RELEASE *)
+
 val find_pred : ('a -> bool) -> 'a t -> 'a option
 (** [find_pred p l] finds the first element of [l] that satisfies [p],
     or returns [None] if no element satisfies [p]