port to the latest ocaml (2004/06/18)gcaml

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/gcaml@6419 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 22 insertions, 4 deletions

diff --git a/stdlib/buffer.ml b/stdlib/buffer.ml
index dcde111ecd..cafec4444c 100644
--- a/stdlib/buffer.ml
+++ b/stdlib/buffer.ml
@@ -11,6 +11,8 @@
 (*                                                                     *)
 (***********************************************************************)
 
+(* $Id$ *)
+
 (* Extensible buffers *)
 
 type t =
@@ -27,6 +29,22 @@ let create n =
 
 let contents b = String.sub b.buffer 0 b.position
 
+let sub b ofs len =
+  if ofs < 0 || len < 0 || ofs > b.position - len 
+  then invalid_arg "Buffer.sub"
+  else begin
+    let r = String.create len in
+    String.blit b.buffer ofs r 0 len;
+    r
+  end
+;;
+
+let nth b ofs = 
+  if ofs < 0 || ofs >= b.position then 
+   invalid_arg "Buffer.nth"
+  else String.get b.buffer ofs
+;;
+
 let length b = b.position
 
 let clear b = b.position <- 0
@@ -87,9 +105,9 @@ let closing = function
   | _ -> assert false;;
 
 (* opening and closing: open and close characters, typically ( and )
-   k balance of opening and closing chars
-   s the string where we are searching
-   start the index where we start the search *)
+   k: balance of opening and closing chars
+   s: the string where we are searching
+   start: the index where we start the search. *)
 let advance_to_closing opening closing k s start =
   let rec advance k i lim =
     if i >= lim then raise Not_found else
@@ -110,7 +128,7 @@ let advance_to_non_alpha s start =
     | _ -> i in
   advance start (String.length s);;
 
-(* We are just at the beginning of an ident in s, starting at start *)
+(* We are just at the beginning of an ident in s, starting at start. *)
 let find_ident s start =
   match s.[start] with
   (* Parenthesized ident ? *)