Minimal changes to support OCaml 4.00

src/batDigest.ml

@@ -67,3 +67,21 @@ in
   assert_equal ~printer:(Printf.sprintf "%S")
     (legacy_result ()) (batteries_result ())
 *)
+
+let from_hex s =
+  if String.length s <> 32 then raise (Invalid_argument "Digest.from_hex");
+  let digit c =
+    match c with
+    | '0'..'9' -> Char.code c - Char.code '0'
+    | 'A'..'F' -> Char.code c - Char.code 'A' + 10
+    | 'a'..'f' -> Char.code c - Char.code 'a' + 10
+    | _ -> raise (Invalid_argument "Digest.from_hex")
+  in
+  let byte i = digit s.[i] lsl 4 + digit s.[i+1] in
+  let result = String.create 16 in
+  for i = 0 to 15 do
+    result.[i] <- Char.chr (byte (2 * i));
+  done;
+  result
+
+let compare = String.compare

src/batDigest.mli

@@ -49,6 +49,12 @@ val file : string -> t
 val to_hex : t -> string
 (** Return the printable hexadecimal representation of the given digest. *)
 
+val from_hex : string -> t
+(** Convert a hexadecimal representation back into the corresponding digest.
+   Raise [Invalid_argument] if the argument is not exactly 32 hexadecimal
+   characters.
+   @since 4.00.0 *)
+
 val channel : input -> int -> Digest.t
 (** If [len] is nonnegative, [Digest.channel ic len] reads [len]
    characters from channel [ic] and returns their digest, or raises
@@ -70,3 +76,11 @@ val print : 'a output -> Digest.t -> unit
 
 val input : input -> Digest.t
 (** Read a digest from the given input. *)
+
+val compare : t -> t -> int
+(** The comparison function for 16-character digest, with the same
+    specification as {!Pervasives.compare} and the implementation
+    shared with {!String.compare}. Along with the type [t], this
+    function [compare] allows the module [Digest] to be passed as
+    argument to the functors {!Set.Make} and {!Map.Make}.
+    @since 4.00.0 *)

src/batHashtbl.ml

@@ -27,7 +27,7 @@
 	Note: We can't directly [include Hashtbl] as this
 	would cause a collision on [Make]*)
     type ('a, 'b) t = ('a, 'b) Hashtbl.t
-    let create   = Hashtbl.create
+    let create s  = Hashtbl.create s
     let clear    = Hashtbl.clear
     let add      = Hashtbl.add
     let copy     = Hashtbl.copy
@@ -523,4 +523,3 @@
 	let find = find_option
       end
     end
-

src/batInnerWeaktbl.ml

@@ -94,7 +94,7 @@ module Make (H: Hashtbl.HashedType) : Hashtbl.S with type key = H.t = struct
   let create = W.create and clear = W.clear
   let find_all tbl key =
     try all_value (W.find tbl (dummy key)) with Not_found-> []
-  let rec find tbl key = top_value (W.find tbl (dummy key))
+  let find tbl key = top_value (W.find tbl (dummy key))
   let add tbl key data =
     let bd = bind_new key data in
     let cls =
@@ -118,6 +118,8 @@ module Make (H: Hashtbl.HashedType) : Hashtbl.S with type key = H.t = struct
   let copy tbl =
     let tbl'= W.create (W.count tbl * 3 / 2 + 2) in
     W.iter (fun cls -> W.add tbl' (Stack.copy cls)) tbl; tbl'
+  let stats _ = assert false
+  let reset _ = assert false
 end
 
 module StdHash = Make
@@ -135,4 +137,3 @@ let replace tbl k = replace tbl (repr k)
 let mem tbl k = mem tbl (repr k)
 let iter f = iter (fun k d -> f (obj k) d)
 let fold f = fold (fun k d a -> f (obj k) d a)
-

src/batSys.ml

@@ -19,6 +19,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *)
 
+let big_endian = false
+
 include Sys
 
 let files_of d = BatArray.enum (readdir d)

src/batSys.mli

@@ -99,6 +99,10 @@ val word_size : int
 (** Size of one word on the machine currently executing the Caml
    program, in bits: 32 or 64. *)
 
+val big_endian : bool
+(** Whether the machine currently executing the Caml program is big-endian.
+    @since 4.00.0 *)
+
 val max_string_length : int
 (** Maximum length of a string. *)