1 files changed, 25 insertions, 21 deletions

diff --git a/stdlib/buffer.ml b/stdlib/buffer.ml
index 78a9e2611..986fe6f33 100644
--- a/stdlib/buffer.ml
+++ b/stdlib/buffer.ml
@@ -14,41 +14,38 @@
 (* Extensible buffers *)
 
 type t =
- {mutable buffer : string;
+ {mutable buffer : bytes;
   mutable position : int;
   mutable length : int;
-  initial_buffer : string}
+  initial_buffer : bytes}
 
 let create n =
  let n = if n < 1 then 1 else n in
  let n = if n > Sys.max_string_length then Sys.max_string_length else n in
- let s = String.create n in
+ let s = Bytes.create n in
  {buffer = s; position = 0; length = n; initial_buffer = s}
 
-let contents b = String.sub b.buffer 0 b.position
+let contents b = Bytes.sub_string b.buffer 0 b.position
+let to_bytes b = Bytes.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.unsafe_blit b.buffer ofs r 0 len;
-    r
-  end
+  else Bytes.sub_string b.buffer ofs len
 ;;
 
 let blit src srcoff dst dstoff len =
   if len < 0 || srcoff < 0 || srcoff > src.position - len
-             || dstoff < 0 || dstoff > (String.length dst) - len
+             || dstoff < 0 || dstoff > (Bytes.length dst) - len
   then invalid_arg "Buffer.blit"
   else
-    String.blit src.buffer srcoff dst dstoff len
+    Bytes.unsafe_blit src.buffer srcoff dst dstoff len
 ;;
 
 let nth b ofs =
   if ofs < 0 || ofs >= b.position then
    invalid_arg "Buffer.nth"
-  else String.unsafe_get b.buffer ofs
+  else Bytes.unsafe_get b.buffer ofs
 ;;
 
 let length b = b.position
@@ -57,7 +54,7 @@ let clear b = b.position <- 0
 
 let reset b =
   b.position <- 0; b.buffer <- b.initial_buffer;
-  b.length <- String.length b.buffer
+  b.length <- Bytes.length b.buffer
 
 let resize b more =
   let len = b.length in
@@ -68,34 +65,41 @@ let resize b more =
     then new_len := Sys.max_string_length
     else failwith "Buffer.add: cannot grow buffer"
   end;
-  let new_buffer = String.create !new_len in
-  String.blit b.buffer 0 new_buffer 0 b.position;
+  let new_buffer = Bytes.create !new_len in
+  (* PR#6148: let's keep using [blit] rather than [unsafe_blit] in
+     this tricky function that is slow anyway. *)
+  Bytes.blit b.buffer 0 new_buffer 0 b.position;
   b.buffer <- new_buffer;
   b.length <- !new_len
 
 let add_char b c =
   let pos = b.position in
   if pos >= b.length then resize b 1;
-  String.unsafe_set b.buffer pos c;
+  Bytes.unsafe_set b.buffer pos c;
   b.position <- pos + 1
 
 let add_substring b s offset len =
-  if offset < 0 || len < 0 || offset > String.length s - len
-  then invalid_arg "Buffer.add_substring";
+  if offset < 0 || len < 0 || offset + len > String.length s
+  then invalid_arg "Buffer.add_substring/add_subbytes";
   let new_position = b.position + len in
   if new_position > b.length then resize b len;
-  String.unsafe_blit s offset b.buffer b.position len;
+  Bytes.blit_string s offset b.buffer b.position len;
   b.position <- new_position
 
+let add_subbytes b s offset len =
+  add_substring b (Bytes.unsafe_to_string s) offset len
+
 let add_string b s =
   let len = String.length s in
   let new_position = b.position + len in
   if new_position > b.length then resize b len;
-  String.unsafe_blit s 0 b.buffer b.position len;
+  Bytes.blit_string s 0 b.buffer b.position len;
   b.position <- new_position
 
+let add_bytes b s = add_string b (Bytes.unsafe_to_string s)
+
 let add_buffer b bs =
-  add_substring b bs.buffer 0 bs.position
+  add_subbytes b bs.buffer 0 bs.position
 
 let add_channel b ic len =
   if len < 0 || len > Sys.max_string_length then   (* PR#5004 *)