hide Seq.diagonals, as an implementation detail

stdlib/seq.ml

@@ -641,6 +641,17 @@ let rec diagonals remainders xss () =
          the remaining rows. *)
       transpose remainders ()
 
+(* If [xss] is a matrix (a sequence of rows), then [diagonals xss] is
+   the sequence of its diagonals.
+
+   The first diagonal contains just the first element of the
+   first row. The second diagonal contains the first element of the
+   second row and the second element of the first row; and so on.
+
+   - Every diagonal is a finite sequence.
+   - The rows of the matrix [xss] are not required to have the same length.
+   - The matrix [xss] is not required to be finite (in either direction).
+   - The matrix [xss] must be persistent. *)
 let diagonals xss =
   diagonals empty xss
 

stdlib/seq.mli

@@ -557,24 +557,6 @@ val transpose : 'a t t -> 'a t t
 
     @since 4.14 *)
 
-val diagonals : 'a t t -> 'a t t
-(** If [xss] is a matrix (a sequence of rows), then [diagonals xss] is
-    the sequence of its diagonals.
-
-    The first diagonal contains just the first element of the
-    first row. The second diagonal contains the first element of the
-    second row and the second element of the first row; and so on.
-
-    Every diagonal is a finite sequence.
-
-    The rows of the matrix [xss] are not required to have the same length.
-
-    The matrix [xss] is not required to be finite (in either direction).
-
-    The matrix [xss] must be persistent.
-
-    @since 4.14 *)
-
 (** {1 Combining sequences} *)
 
 val append : 'a t -> 'a t -> 'a t