Adding String.iteri.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@10762 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/string.ml

@@ -60,6 +60,9 @@ let blit s1 ofs1 s2 ofs2 len =
 let iter f a =
   for i = 0 to length a - 1 do f(unsafe_get a i) done
 
+let iteri f a =
+  for i = 0 to length a - 1 do f i (unsafe_get a i) done
+
 let concat sep l =
   match l with
     [] -> ""

stdlib/string.mli

@@ -94,6 +94,13 @@ val iter : (char -> unit) -> string -> unit
    the characters of [s].  It is equivalent to
    [f s.[0]; f s.[1]; ...; f s.[String.length s - 1]; ()]. *)
 
+val iteri : (int -> char -> unit) -> string -> unit
+(** Same as {!String.iter}, but the
+   function is applied to the index of the element as first argument (counting from 0),
+   and the character itself as second argument.
+   @since 3.13.0
+*)
+
 val escaped : string -> string
 (** Return a copy of the argument, with special characters
    represented by escape sequences, following the lexical

stdlib/stringLabels.mli

@@ -84,6 +84,13 @@ val iter : f:(char -> unit) -> string -> unit
    the characters of [s].  It is equivalent to
    [f s.[0]; f s.[1]; ...; f s.[String.length s - 1]; ()]. *)
 
+val iteri : f:(int -> char -> unit) -> string -> unit
+(** Same as {!String.iter}, but the
+   function is applied to the index of the element as first argument (counting from 0),
+   and the character itself as second argument.
+   @since 3.13.0
+*)
+
 val escaped : string -> string
 (** Return a copy of the argument, with special characters
    represented by escape sequences, following the lexical