diff --git a/KMP.ml b/KMP.ml
new file mode 100644
index 00000000..dafecace
--- /dev/null
+++ b/KMP.ml
@@ -0,0 +1,158 @@
+
+(*
+copyright (c) 2013-2014, simon cruanes
+all rights reserved.
+
+redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Knuth-Morris-Pratt} *)
+
+module type STRING = sig
+  type t
+  type char
+
+  val length : t -> int
+  val get : t -> int -> char
+  val char_equal : char -> char -> bool
+end
+
+type 'a gen = unit -> 'a option
+
+module type S = sig
+  type string
+
+  type pattern
+  (** Compiled pattern (needle: string to search in another string) *)
+
+  val compile : string -> pattern
+  (** Compile a string into a pattern *)
+
+  val find : pattern:pattern -> string -> int -> int option
+  (** [find ~pattern s i] finds the next occurrence of [pattern]
+      in [s] starting at offset [i], and returns it,
+      or returns [None] if the pattern doesn't occur. *)
+
+  val search : pattern:pattern -> string -> int option
+  (** [search ~pattern s] is a shortcut for [find ~pattern s 0]. *)
+
+  val find_all : pattern:pattern -> string -> int -> int gen
+  (** Generator on all occurrences of the pattern *)
+
+  (** {6 One-shot functions that compile the pattern on-the-fly} *)
+
+  val search' : pattern:string -> string -> int option
+
+  val find_all' : pattern:string -> string -> int gen
+end
+
+module Make(Str : STRING) = struct
+  type string = Str.t
+  type pattern = {
+    failure : int array;
+    str : Str.t;
+    len : int;  (* = length str = length failure *)
+  }
+
+  let compile str =
+    let len = Str.length str in
+    match len with
+    | 0 -> {failure=[| |]; len; str;}
+    | 1 -> {failure=[| -1 |]; len; str;}
+    | _ ->
+      (* at least 2 elements, the algorithm can work *)
+      let failure = Array.make len 0 in
+      (* i: current index in str *)
+      let i = ref 1 in
+      (* j: index of candidate substring *)
+      let j = ref 0 in
+      while !i < len-1 do
+        match !j with
+        | _ when Str.char_equal (Str.get str !i) (Str.get str !j) ->
+          (* substring starting at !j continues matching current char *)
+          i := !i+1;
+          j := !j+1;
+          failure.(!i) <- !j;
+        | 0 ->
+          (* back to the beginning *)
+          i := !i+1;
+          failure.(!i) <- 0;
+        | _ ->
+          (* fallback for the prefix string *)
+          assert (!j > 0);
+          j := failure.(!j)
+      done;
+      { failure; str; len; }
+
+  let find ~pattern s idx =
+    (* proper search function.
+      [i] index in [s]
+      [j] index in [pattern]
+      [len] length of [s] *)
+    let len = Str.length s in
+    let i = ref idx in
+    let j = ref 0 in
+    while !i < len && !j < pattern.len do
+      let c = Str.get s !i in
+      let expected = Str.get pattern.str !j in
+      if Str.char_equal c expected
+      then (
+        (* char matches *)
+        i := !i + 1; j := !j + 1
+      ) else
+        if !j=0
+          then (* beginning of the pattern *)
+            i := !i + 1
+          else (* follow the failure link *)
+            j := pattern.failure.(!j)
+    done;
+    if !j = pattern.len
+      then Some (!i-pattern.len)
+      else None
+
+  let search ~pattern s = find ~pattern s 0
+
+  let find_all ~pattern s i =
+    let i = ref i in
+    fun () ->
+      if !i >= Str.length s
+      then None
+      else match find ~pattern s !i with
+      | None -> None
+      | (Some j) as res ->
+          i := j + pattern.len;
+          res
+
+  let search' ~pattern s =
+    search ~pattern:(compile pattern) s
+
+  let find_all' ~pattern s =
+    find_all ~pattern:(compile pattern) s 0
+end
+
+module Default = Make(struct
+  type char_ = char
+  type char = char_
+  type t = string
+  let char_equal a b = a=b
+  let get = String.get
+  let length = String.length
+end)
diff --git a/KMP.mli b/KMP.mli
new file mode 100644
index 00000000..a2cc09f6
--- /dev/null
+++ b/KMP.mli
@@ -0,0 +1,69 @@
+
+(*
+copyright (c) 2013-2014, simon cruanes
+all rights reserved.
+
+redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Knuth-Morris-Pratt} *)
+
+module type STRING = sig
+  type t
+  type char
+
+  val length : t -> int
+  val get : t -> int -> char
+  val char_equal : char -> char -> bool
+end
+
+type 'a gen = unit -> 'a option
+
+module type S = sig
+  type string
+
+  type pattern
+  (** Compiled pattern (needle: string to search in another string) *)
+
+  val compile : string -> pattern
+  (** Compile a string into a pattern *)
+
+  val find : pattern:pattern -> string -> int -> int option
+  (** [find ~pattern s i] finds the next occurrence of [pattern]
+      in [s] starting at offset [i], and returns it,
+      or returns [None] if the pattern doesn't occur. *)
+
+  val search : pattern:pattern -> string -> int option
+  (** [search ~pattern s] is a shortcut for [find ~pattern s 0]. *)
+
+  val find_all : pattern:pattern -> string -> int -> int gen
+  (** Generator on all occurrences of the pattern *)
+
+  (** {6 One-shot functions that compile the pattern on-the-fly} *)
+
+  val search' : pattern:string -> string -> int option
+
+  val find_all' : pattern:string -> string -> int gen
+end
+
+module Make(Str : STRING) : S with type string = Str.t
+
+module Default : S with type string = string
diff --git a/_oasis b/_oasis
index c8dcef11..efd56b7d 100644
--- a/_oasis
+++ b/_oasis
@@ -41,7 +41,7 @@ Library "containers"
                     UnionFind, SmallSet, Leftistheap, AbsSet, CSM, MultiMap,
                     ActionMan, BV, QCheck, BencodeOnDisk, Show, TTree,
                     HGraph, Automaton, Conv, Levenshtein, Bidir, Iteratee,
-                    Ty, Tell, BencodeStream, RatTerm, Cause
+                    Ty, Tell, BencodeStream, RatTerm, Cause, KMP
   BuildDepends:     unix
 
 Library "containers_thread"
diff --git a/_tags b/_tags
index b8d7a0a7..a0ddaf26 100644
--- a/_tags
+++ b/_tags
@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: a253a3102af478e2c2a6c4a7d330a848)
+# DO NOT EDIT (digest: 13877dc814f0b2dee886bafc27842dfc)
 # Ignore VCS directories, you can use the same kind of rule outside
 # OASIS_START/STOP if you want to exclude directories that contains
 # useless stuff for the build process
@@ -62,6 +62,7 @@
 "bencodeStream.cmx": for-pack(Containers)
 "ratTerm.cmx": for-pack(Containers)
 "cause.cmx": for-pack(Containers)
+"KMP.cmx": for-pack(Containers)
 # Library containers_thread
 "threads/containers_thread.cmxs": use_containers_thread
 <threads/*.ml{,i}>: package(threads)
diff --git a/containers.mlpack b/containers.mlpack
index 3790fe30..d5f309a5 100644
--- a/containers.mlpack
+++ b/containers.mlpack
@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: 9824af535a520376fdb1b1ac58c878c9)
+# DO NOT EDIT (digest: 404fe51c40218ed7bf430446cec5efde)
 Cache
 Deque
 Gen
@@ -47,4 +47,5 @@ Tell
 BencodeStream
 RatTerm
 Cause
+KMP
 # OASIS_STOP
diff --git a/containers.odocl b/containers.odocl
index 3790fe30..d5f309a5 100644
--- a/containers.odocl
+++ b/containers.odocl
@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: 9824af535a520376fdb1b1ac58c878c9)
+# DO NOT EDIT (digest: 404fe51c40218ed7bf430446cec5efde)
 Cache
 Deque
 Gen
@@ -47,4 +47,5 @@ Tell
 BencodeStream
 RatTerm
 Cause
+KMP
 # OASIS_STOP
diff --git a/setup.ml b/setup.ml
index b2614038..9a2d285c 100644
--- a/setup.ml
+++ b/setup.ml
@@ -1,7 +1,7 @@
 (* setup.ml generated for the first time by OASIS v0.3.0 *)
 
 (* OASIS_START *)
-(* DO NOT EDIT (digest: d81d54173b4f70a25124ba24fef82bc2) *)
+(* DO NOT EDIT (digest: b545212f57a5e5b473eeea4866484af0) *)
 (*
    Regenerated by OASIS v0.4.4
    Visit http://oasis.forge.ocamlcore.org for more information and
@@ -7005,7 +7005,8 @@ let setup_t =
                            "Tell";
                            "BencodeStream";
                            "RatTerm";
-                           "Cause"
+                           "Cause";
+                           "KMP"
                         ];
                       lib_pack = true;
                       lib_internal_modules = [];
@@ -7392,7 +7393,7 @@ let setup_t =
        };
      oasis_fn = Some "_oasis";
      oasis_version = "0.4.4";
-     oasis_digest = Some "\242\031\132\250-\201+\tJ\171/\017\158\211\194\168";
+     oasis_digest = Some "\228\227\"@\138\216\007\132\190[\139\215a\153B<";
      oasis_exec = None;
      oasis_setup_args = [];
      setup_update = false
@@ -7400,6 +7401,6 @@ let setup_t =
 
 let setup () = BaseSetup.setup setup_t;;
 
-# 7404 "setup.ml"
+# 7405 "setup.ml"
 (* OASIS_STOP *)
 let () = setup ();;