From b695918e998bf9efb36090d33911a5d01a331bd0 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sat, 2 Jul 2022 00:29:25 -0400
Subject: [PATCH] move all core tests to new testlib

---
 src/bencode/containers_bencode.ml  |  55 ----
 src/core/CCEqualLabels.mli         |  25 +-
 src/core/CCHashtbl.ml              |  56 ----
 src/core/CCHeap.ml                 |  92 ------
 src/core/CCIO.ml                   |  71 -----
 src/core/CCInt.ml                  | 163 ----------
 src/core/CCInt32.ml                |  75 -----
 src/core/CCInt64.ml                |  75 -----
 src/core/CCMap.ml                  |  28 --
 src/core/CCNativeint.ml            |  75 -----
 src/core/CCOption.ml               |  40 ---
 src/core/CCOrd.ml                  |  56 ----
 src/core/CCParse.ml                | 229 --------------
 src/core/CCRandom.ml               |  17 --
 src/core/CCResult.ml               |  43 ---
 src/core/CCSeq.ml                  | 130 --------
 src/core/CCSet.ml                  |  23 --
 src/core/CCSexp.ml                 |  88 ------
 src/core/CCString.ml               | 343 ---------------------
 src/core/CCUtf8_string.ml          | 181 -----------
 src/core/CCVector.ml               | 468 -----------------------------
 src/testlib/containers_testlib.ml  |  11 +-
 src/testlib/containers_testlib.mli |   2 +-
 src/unix/CCUnix.ml                 |  53 ----
 tests/core/compat/dune             |   5 +
 tests/core/compat/t_compat.ml      |   9 +
 tests/core/dune                    |   4 +-
 tests/core/t.ml                    |  21 ++
 tests/core/t_IO.ml                 |  69 +++++
 tests/core/t_bencode.ml            |  57 ++++
 tests/core/t_eq.ml                 |   2 +-
 tests/core/t_hashtbl.ml            |  55 ++++
 tests/core/t_heap.ml               |  87 ++++++
 tests/core/t_int.ml                | 132 ++++++++
 tests/core/t_int32.ml              |  66 ++++
 tests/core/t_int64.ml              |  65 ++++
 tests/core/t_map.ml                |  27 ++
 tests/core/t_nativeint.ml          |  67 +++++
 tests/core/t_option.ml             |  25 ++
 tests/core/t_ord.ml                |  43 +++
 tests/core/t_parse.ml              | 214 +++++++++++++
 tests/core/t_random.ml             |  19 ++
 tests/core/t_result.ml             |  32 ++
 tests/core/t_seq.ml                |  88 ++++++
 tests/core/t_set.ml                |  22 ++
 tests/core/t_sexp.ml               |  80 +++++
 tests/core/t_string.ml             | 264 ++++++++++++++++
 tests/core/t_unix.ml               |  48 +++
 tests/core/t_utf8string.ml         | 162 ++++++++++
 tests/core/t_vector.ml             | 361 ++++++++++++++++++++++
 50 files changed, 2039 insertions(+), 2384 deletions(-)
 create mode 100644 tests/core/compat/dune
 create mode 100644 tests/core/compat/t_compat.ml
 create mode 100644 tests/core/t_IO.ml
 create mode 100644 tests/core/t_bencode.ml
 create mode 100644 tests/core/t_hashtbl.ml
 create mode 100644 tests/core/t_heap.ml
 create mode 100644 tests/core/t_int.ml
 create mode 100644 tests/core/t_int32.ml
 create mode 100644 tests/core/t_int64.ml
 create mode 100644 tests/core/t_map.ml
 create mode 100644 tests/core/t_nativeint.ml
 create mode 100644 tests/core/t_option.ml
 create mode 100644 tests/core/t_ord.ml
 create mode 100644 tests/core/t_parse.ml
 create mode 100644 tests/core/t_random.ml
 create mode 100644 tests/core/t_result.ml
 create mode 100644 tests/core/t_seq.ml
 create mode 100644 tests/core/t_set.ml
 create mode 100644 tests/core/t_sexp.ml
 create mode 100644 tests/core/t_string.ml
 create mode 100644 tests/core/t_unix.ml
 create mode 100644 tests/core/t_utf8string.ml
 create mode 100644 tests/core/t_vector.ml

diff --git a/src/bencode/containers_bencode.ml b/src/bencode/containers_bencode.ml
index 1ec9f692..88ce7d62 100644
--- a/src/bencode/containers_bencode.ml
+++ b/src/bencode/containers_bencode.ml
@@ -157,58 +157,3 @@ module Decode = struct
     | Some x -> x
     | None -> failwith "bencode.decode: invalid string"
 end
-
-(*$= & ~printer:to_string_debug
-  (map_of_list []) (Decode.of_string_exn "de")
-  (list [int 1; int 2; string "foo"]) (Decode.of_string_exn "li1ei2e3:fooe")
-*)
-
-(*$inject
-  module B = Containers_bencode
-
-  let rec size = function
-    | Int _ | String _ -> 1
-    | List l -> List.fold_left (fun n x -> n + size x) 0 l
-    | Map m -> Str_map.fold(fun _ v n -> size v + n) m 0
-
-  let g_rand_b =
-    Q.Gen.(
-      sized_size (0--7) @@ fix @@ fun self n ->
-        let str n = string_size ~gen:char (0 -- n) in
-        let base = [
-         int >|= B.int;
-         str 100 >|= B.string;
-       ] in
-      match n with
-     | 0 -> oneof base
-     | n ->
-       frequency @@
-        List.map (fun x -> 2, x) base @
-        [ 1, list_size (0 -- 10) (self (n-1)) >|= B.list;
-          1, list_size (0 -- 10) (pair (str 10) (self (n-1)) ) >|= B.map_of_list;
-        ]
-    )
-
-  let rec shrink_b self = Q.(Iter.(
-    match self with
-    | Int i -> Shrink.int64 i >|= B.int64
-    | String s -> Shrink.string s >|= B.string
-    | List l -> Shrink.list ~shrink:shrink_b l >|= B.list
-    | Map l ->
-        let l = Str_map.fold (fun k v l -> (k,v) :: l) l [] in
-        Shrink.list ~shrink:(fun (k,v) ->
-          (Shrink.string k >|= fun k -> k,v) <+>
-          (shrink_b v >|= fun v -> k,v))
-          l
-        >|= B.map_of_list
-    ))
-
-  let rand_b = Q.make ~print:to_string_debug ~stats:["size", size]
-    ~shrink:shrink_b g_rand_b
-  *)
-
-(*$Q
-  rand_b (fun b -> \
-    let s=Encode.to_string b in \
-    equal (Decode.of_string_exn s) b)
-*)
diff --git a/src/core/CCEqualLabels.mli b/src/core/CCEqualLabels.mli
index 764abe2d..4014ac5e 100644
--- a/src/core/CCEqualLabels.mli
+++ b/src/core/CCEqualLabels.mli
@@ -36,24 +36,19 @@ val map : f:('a -> 'b) -> 'b t -> 'a t
     [map fst int] compares values of type [(int * 'a)]  by their
       first component. *)
 
+val always_eq : _ t
+(** Always returns true. All values are equal.
+    @since NEXT_RELEASE *)
+
+val never_eq : _ t
+(** Always returns false. No values are, so this
+    is not even reflexive (i.e. [x=x] is false).
+    Be careful!
+    @since NEXT_RELEASE *)
+
 module Infix : sig
   val (>|=) : 'b t -> ('a -> 'b) -> 'a t
   (** Infix equivalent of {!map}. *)
 end
 
 include module type of Infix
-
-(* test consistency of interfaces *)
-(*$inject
-  module type L = module type of CCEqual
-  module type LL = module type of CCEqualLabels
-*)
-
-(*$R
-  ignore (module CCEqualLabels : L)
-*)
-
-(*$R
-  ignore (module CCEqual : LL)
-*)
-
diff --git a/src/core/CCHashtbl.ml b/src/core/CCHashtbl.ml
index ed69ff88..ae14ff53 100644
--- a/src/core/CCHashtbl.ml
+++ b/src/core/CCHashtbl.ml
@@ -19,10 +19,6 @@ module Poly = struct
     try Hashtbl.find tbl x
     with Not_found -> default
 
-  (*$=
-    "c" (let tbl = of_list [1,"a"; 2,"b"] in get_or tbl 3 ~default:"c")
-    "b" (let tbl = of_list [1,"a"; 2,"b"] in get_or tbl 2 ~default:"c")
-  *)
 
   let keys tbl k = Hashtbl.iter (fun key _ -> k key) tbl
 
@@ -54,11 +50,6 @@ module Poly = struct
       (fun x y acc -> f x y :: acc)
       h []
 
-  (*$T
-    of_list [1,"a"; 2,"b"] |> map_list (fun x y -> string_of_int x ^ y) \
-      |> List.sort Stdlib.compare = ["1a"; "2b"]
-  *)
-
   let to_iter tbl k = Hashtbl.iter (fun key v -> k (key,v)) tbl
 
   let add_iter tbl i = i (fun (k,v) -> Hashtbl.add tbl k v)
@@ -123,17 +114,6 @@ module Poly = struct
       | Some _, Some v' -> Hashtbl.replace tbl k v'
       | Some _, None -> Hashtbl.remove tbl k
 
-  (*$R
-    let tbl = Hashtbl.create 32 in
-    update tbl ~f:(fun _ _ -> Some "1") ~k:1;
-    assert_equal (Some "1") (get tbl 1);
-    update tbl ~f:(fun _ v->match v with Some _ -> assert false | None -> Some "2") ~k:2;
-    assert_equal (Some "2") (get tbl 2);
-    assert_equal 2 (Hashtbl.length tbl);
-    update tbl ~f:(fun _ _ -> None) ~k:1;
-    assert_equal None (get tbl 1);
-  *)
-
   let get_or_add tbl ~f ~k =
     try Hashtbl.find tbl k
     with Not_found ->
@@ -141,19 +121,6 @@ module Poly = struct
       Hashtbl.add tbl k v;
       v
 
-  (*$R
-    let tbl = Hashtbl.create 32 in
-    let v1 = get_or_add tbl ~f:(fun _ -> "1") ~k:1 in
-    assert_equal "1" v1;
-    assert_equal (Some "1") (get tbl 1);
-    let v2 = get_or_add tbl ~f:(fun _ ->"2") ~k:2 in
-    assert_equal "2" v2;
-    assert_equal (Some "2") (get tbl 2);
-    assert_equal "2" (get_or_add tbl ~f:(fun _ -> assert false) ~k:2);
-    assert_equal 2 (Hashtbl.length tbl);
-    ()
-  *)
-
   let pp ?(pp_start=fun _ () -> ()) ?(pp_stop=fun _ () -> ())
       ?(pp_sep=fun fmt () -> Format.fprintf fmt ",@ ")
       ?(pp_arrow=fun fmt () -> Format.fprintf fmt "@ -> ") pp_k pp_v fmt m =
@@ -342,10 +309,6 @@ module type S = sig
       @since 0.13 *)
 end
 
-(*$inject
-  module T = Make(CCInt)
-*)
-
 module Make(X : Hashtbl.HashedType)
   : S with type key = X.t and type 'a t = 'a Hashtbl.Make(X).t
 = struct
@@ -359,31 +322,12 @@ module Make(X : Hashtbl.HashedType)
     try find tbl x
     with Not_found -> default
 
-  (*$=
-    "c" (let tbl = T.of_list [1,"a"; 2,"b"] in T.get_or tbl 3 ~default:"c")
-    "b" (let tbl = T.of_list [1,"a"; 2,"b"] in T.get_or tbl 2 ~default:"c")
-  *)
-
   let incr ?(by=1) tbl x =
     let n = get_or tbl x ~default:0 in
     if n+by <= 0
     then remove tbl x
     else replace tbl x (n+by)
 
-  (*$R
-    let tbl = T.create 32 in
-    T.incr tbl 1 ;
-    T.incr tbl 2;
-    T.incr tbl 1;
-    assert_equal 2 (T.find tbl 1);
-    assert_equal 1 (T.find tbl 2);
-    assert_equal 2 (T.length tbl);
-    T.decr tbl 2;
-    assert_equal 0 (T.get_or tbl 2 ~default:0);
-    assert_equal 1 (T.length tbl);
-    assert_bool "2 removed" (not (T.mem tbl 2));
-  *)
-
   let add_list tbl k v =
     let l = try find tbl k with Not_found -> [] in
     replace tbl k (v::l)
diff --git a/src/core/CCHeap.ml b/src/core/CCHeap.ml
index 0b986f91..01acd3c8 100644
--- a/src/core/CCHeap.ml
+++ b/src/core/CCHeap.ml
@@ -23,69 +23,6 @@ module type TOTAL_ORD = sig
       a positive value if [a] is greater than [b] *)
 end
 
-(*$inject
-  module H = CCHeap.Make(struct
-    type t = int
-    let leq x y = x<=y
-  end)
-
-  let rec is_sorted l = match l with
-    | [_]
-    | [] -> true
-    | x::((y::_) as l') -> x <= y && is_sorted l'
-
-  let extract_list = H.to_list_sorted
-*)
-
-(*$R
-  let h = H.of_list [5;3;4;1;42;0] in
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 0 x;
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 1 x;
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 3 x;
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 4 x;
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 5 x;
-  let h, x = H.take_exn h in
-  OUnit2.assert_equal ~printer:string_of_int 42 x;
-  OUnit2.assert_raises H.Empty (fun () -> H.take_exn h);
-*)
-
-(*$QR & ~count:30
-  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
-    (* put elements into a heap *)
-    let h = H.of_iter (Iter.of_list l) in
-    OUnit2.assert_equal 1_000 (H.size h);
-    let l' = extract_list h in
-    is_sorted l'
-  )
-*)
-
-(* test filter *)
-(*$QR & ~count:30
-  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
-    (* put elements into a heap *)
-    let h = H.of_iter (Iter.of_list l) in
-    let h = H.filter (fun x->x mod 2=0) h in
-    OUnit2.assert_bool "all odd"
-      (H.to_iter h |> Iter.for_all (fun x -> x mod 2 = 0));
-    let l' = extract_list h in
-    is_sorted l'
-  )
-*)
-
-(*$QR
-  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
-    (* put elements into a heap *)
-    let h = H.of_iter (Iter.of_list l) in
-    let l' = H.to_iter_sorted h |> Iter.to_list in
-    is_sorted l'
-  )
-*)
-
 module type S = sig
   type elt
   type t
@@ -405,16 +342,6 @@ module Make(E : PARTIAL_ORD) : S with type elt = E.t = struct
           Some x
     in next
 
-  (*$Q
-    Q.(list int) (fun l -> \
-      extract_list (H.of_list l) = \
-        extract_list (H.of_gen (CCList.to_gen l)))
-    Q.(list int) (fun l -> \
-      let h = H.of_list l in \
-      (H.to_gen h |> CCList.of_gen |> List.sort Stdlib.compare) \
-        = (H.to_list h |> List.sort Stdlib.compare))
-  *)
-
   let rec to_tree h () = match h with
     | E -> `Nil
     | N (_, x, l, r) -> `Node(x, [to_tree l; to_tree r])
@@ -424,17 +351,6 @@ module Make(E : PARTIAL_ORD) : S with type elt = E.t = struct
     |> List.map elt_to_string
     |> String.concat sep
 
-  (*$Q
-    Q.(list int) (fun l -> \
-      let h = H.of_list l in \
-      (H.to_string string_of_int h) \
-        = (List.sort Stdlib.compare l |> List.map string_of_int |> String.concat ","))
-    Q.(list int) (fun l -> \
-      let h = H.of_list l in \
-      (H.to_string ~sep:" " string_of_int h) \
-        = (List.sort Stdlib.compare l |> List.map string_of_int |> String.concat " "))
-  *)
-
   let pp ?(pp_start=fun _ () -> ()) ?(pp_stop=fun _ () -> ())
       ?(pp_sep=fun out () -> Format.fprintf out ",") pp_elt out h =
     let first=ref true in
@@ -453,11 +369,3 @@ module Make_from_compare(E : TOTAL_ORD) =
     let leq a b = E.compare a b <= 0
   end)
 
-(*$QR
-  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
-    let module H' = Make_from_compare(CCInt) in
-    let h = H'.of_list l in
-    let l' = H'.to_list_sorted h in
-    is_sorted l'
-  )
-*)
diff --git a/src/core/CCIO.ml b/src/core/CCIO.ml
index 8bc329c0..29c90af0 100644
--- a/src/core/CCIO.ml
+++ b/src/core/CCIO.ml
@@ -167,19 +167,6 @@ let read_all_bytes ?(size=1024) ic = read_all_ ~op:Ret_bytes ~size ic
 
 let read_all ?(size=1024) ic = read_all_ ~op:Ret_string ~size ic
 
-(*$R
-  let s = String.make 200 'y' in
-  let s = Printf.sprintf "a\nb\n %s\nlast line\n" s in
-  File.with_temp ~prefix:"test_containers" ~suffix:""
-    (fun name ->
-      with_out name @@ fun oc ->
-      output_string oc s;
-      flush oc;
-      let s' = with_in name read_all in
-      OUnit2.assert_equal ~printer:(fun s->s) s s'
-    )
-*)
-
 
 let with_out ?(mode=0o644) ?(flags=[Open_creat; Open_trunc; Open_text]) filename f =
   let oc = open_out_gen (Open_wronly::flags) mode filename in
@@ -235,34 +222,6 @@ let write_lines_l oc l =
 (* test {read,write}_lines. Need to concatenate the lists because some
    strings in the random input might contain '\n' themselves *)
 
-(*$QR
-   Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
-     let l' = ref [] in
-     File.with_temp ~prefix:"test_containers" ~suffix:""
-      (fun name ->
-        with_out name @@ fun oc ->
-        write_lines_l oc l;
-        flush oc;
-        l' := with_in name read_lines_l;
-      );
-     String.concat "\n" l = String.concat "\n" !l'
-    )
-*)
-
-(*$QR
-   Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
-     let l' = ref [] in
-     File.with_temp ~prefix:"test_containers" ~suffix:""
-      (fun name ->
-        with_out name @@ fun oc ->
-        write_lines oc (Gen.of_list l);
-        flush oc;
-        l' := with_in name (fun ic -> read_lines_gen ic |> Gen.to_list);
-      );
-     String.concat "\n" l = String.concat "\n" !l'
-    )
-*)
-
 let with_in_out ?(mode=0o644) ?(flags=[Open_creat]) filename f =
   let ic = open_in_gen (Open_rdonly::flags) mode filename in
   let oc = open_out_gen (Open_wronly::flags) mode filename in
@@ -288,25 +247,6 @@ let copy_into ?(bufsize=4_096) ic oc : unit =
     )
   done
 
-(*$QR
-   Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
-     let s = ref "" in
-     File.with_temp ~prefix:"test_containers1" ~suffix:""
-      (fun name1 ->
-        with_out name1 @@ fun oc1 ->
-        write_gen ~sep:"" oc1 (Gen.of_list l);
-        flush oc1;
-        File.with_temp ~prefix:"test_containers2" ~suffix:""
-          (fun name2 ->
-             with_out name2 @@ fun oc2 ->
-             CCIO.with_in name1 (fun ic1 -> copy_into ic1 oc2);
-             flush oc2;
-             s := with_in name2 read_all;);
-      );
-     String.concat "" l = !s
-    )
-*)
-
 let tee funs g () = match g() with
   | None -> None
   | Some x as res ->
@@ -394,17 +334,6 @@ module File = struct
     )
     else gen_singleton (`File, d)
 
-  (*$R
-    OUnit2.assert_bool "walk categorizes files"
-      (File.walk "."
-        |> Gen.for_all
-          (function
-            | `File, f -> not (Sys.is_directory f)
-            | `Dir, f -> Sys.is_directory f
-          )
-      )
-  *)
-
   let walk_seq d = seq_of_gen_ (walk d)
   let walk_iter d = fun yield -> gen_iter yield (walk d)
 
diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index 8f2e38f6..ff466136 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -74,23 +74,11 @@ let range i j yield =
   in
   if i<=j then up i j yield else down i j yield
 
-(*$= & ~printer:Q.Print.(list int)
-  [0;1;2;3;4;5] (range 0 5 |> Iter.to_list)
-  [0]           (range 0 0 |> Iter.to_list)
-  [5;4;3;2]     (range 5 2 |> Iter.to_list)
-*)
-
 let range' i j yield =
   if i<j then range i (j-1) yield
   else if i=j then ()
   else range i (j+1) yield
 
-(*$= & ~printer:Q.Print.(list int)
-  []          (range' 0 0 |> Iter.to_list)
-  [0;1;2;3;4] (range' 0 5 |> Iter.to_list)
-  [5;4;3]     (range' 5 2 |> Iter.to_list)
-*)
-
 let sign i = compare i 0
 
 let neg i = -i
@@ -108,14 +96,6 @@ let pow a b =
     | b when b < 0 -> raise (Invalid_argument "pow: can't raise int to negative power")
     | b -> aux a b
 
-(*$T
-  pow 2 10 = 1024
-  pow 2 15 = 32768
-  pow 10 5 = 100000
-  pow 1 0 = 1
-  pow 0 1 = 0
-*)
-
 module Infix : sig
   val (=) : t -> t -> bool
   val (<>) : t -> t -> bool
@@ -158,36 +138,6 @@ let floor_div a n =
   else
     a / n
 
-(*$T
-  (floor_div 3 5 = 0)
-  (floor_div 5 5 = 1)
-  (floor_div 20 5 = 4)
-  (floor_div 12 5 = 2)
-  (floor_div 0 5 = 0)
-  (floor_div (-1) 5 = -1)
-  (floor_div (-5) 5 = -1)
-  (floor_div (-12) 5 = -3)
-
-  (floor_div 0 (-5) = 0)
-  (floor_div 3 (-5) = -1)
-  (floor_div 5 (-5) = -1)
-  (floor_div 9 (-5) = -2)
-  (floor_div 20 (-5) = -4)
-  (floor_div (-2) (-5) = 0)
-  (floor_div (-8) (-5) = 1)
-  (floor_div (-35) (-5) = 7)
-
-  try ignore (floor_div 12 0); false with Division_by_zero -> true
-  try ignore (floor_div (-12) 0); false with Division_by_zero -> true
-*)
-
-(*$Q
-  (Q.pair Q.small_signed_int Q.pos_int) \
-      (fun (n, m) -> floor_div n m = int_of_float @@ floor (float n /. float m))
-  (Q.pair Q.small_signed_int Q.pos_int) \
-      (fun (n, m) -> floor_div n (-m) = int_of_float @@ floor (float n /. float (-m)))
-*)
-
 let bool_neq (a : bool) b = Stdlib.(<>) a b
 
 let rem a n =
@@ -197,38 +147,6 @@ let rem a n =
   else
     y
 
-(*$T
-  (rem 3 5 = 3)
-  (rem 5 5 = 0)
-  (rem 9 5 = 4)
-  (rem (-1) 5 = 4)
-  (rem (-5) 5 = 0)
-  (rem (-20) 5 = 0)
-  (rem (-9) 5 = 1)
-  (rem 0 5 = 0)
-
-  (rem 0 (-5) = 0)
-  (rem 3 (-5) = -2)
-  (rem 5 (-5) = 0)
-  (rem 9 (-5) = -1)
-  (rem (-2) (-5) = -2)
-  (rem (-8) (-5) = -3)
-  (rem (-35) (-5) = 0)
-
-  try ignore (rem 12 0); false with Division_by_zero -> true
-  try ignore (rem (-12) 0); false with Division_by_zero -> true
-*)
-
-(*$Q
-  (Q.pair Q.int Q.pos_int) (fun (n, m) -> let y = rem n m in y >= 0 && y < m)
-  (Q.pair Q.int Q.pos_int) (fun (n, m) -> let y = rem n (-m) in y > (-m) && y <= 0)
-*)
-
-(*$Q
-  (Q.pair Q.int Q.pos_int) (fun (n, m) -> n = m * floor_div n m + rem n m)
-  (Q.pair Q.int Q.pos_int) (fun (n, m) -> n = (-m) * floor_div n (-m) + rem n (-m))
-*)
-
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 
@@ -247,21 +165,12 @@ let of_string s =
   try Some (int_of_string s)
   with Failure _ -> None
 
-(*$=
-  None (of_string "moo")
-  (Some 42) (of_string "42")
-*)
-
 let of_string_exn = Stdlib.int_of_string
 
 let to_float = float_of_int
 
 let of_float = int_of_float
 
-(*$=
-  1 (of_float 1.2)
-*)
-
 type output = char -> unit
 
 (* abstract printer *)
@@ -292,17 +201,6 @@ let to_string_binary n =
   to_binary_gen (Buffer.add_char buf) n;
   Buffer.contents buf
 
-(*$= & ~printer:CCFun.id
-  "0b111" (to_string_binary 7)
-  "-0b111" (to_string_binary (-7))
-  "0b0" (to_string_binary 0)
-*)
-
-
-(*$Q & ~count:10_000
-  Q.int (fun n -> n = int_of_string (to_string_binary n))
-*)
-
 let range_by ~step i j yield =
   let rec range i j yield =
     if i=j then yield i
@@ -316,29 +214,6 @@ let range_by ~step i j yield =
   else if (if step > 0 then i>j else i<j) then ()
   else range i ((j-i)/step*step + i) yield
 
-(* note: the last test checks that no error occurs due to overflows. *)
-(*$= & ~printer:Q.Print.(list int)
-  [0]     (range_by ~step:1   0 0     |> Iter.to_list)
-  []      (range_by ~step:1   5 0     |> Iter.to_list)
-  []      (range_by ~step:2   1 0     |> Iter.to_list)
-  [0;2;4] (range_by ~step:2   0 4     |> Iter.to_list)
-  [0;2;4] (range_by ~step:2   0 5     |> Iter.to_list)
-  [0]     (range_by ~step:~-1 0 0     |> Iter.to_list)
-  []      (range_by ~step:~-1 0 5     |> Iter.to_list)
-  []      (range_by ~step:~-2 0 1     |> Iter.to_list)
-  [5;3;1] (range_by ~step:~-2 5 1     |> Iter.to_list)
-  [5;3;1] (range_by ~step:~-2 5 0     |> Iter.to_list)
-  [0]     (range_by ~step:max_int 0 2 |> Iter.to_list)
-*)
-
-(*$Q
-  Q.(pair small_int small_int) (fun (i,j) -> \
-    let i = min i j and j = max i j in \
-    CCList.equal CCInt.equal \
-      (CCInt.range_by ~step:1 i j |> Iter.to_list) \
-      (CCInt.range i j |> Iter.to_list) )
-*)
-
 (*
   from https://en.wikipedia.org/wiki/Hamming_weight
 
@@ -377,44 +252,6 @@ let popcount (b:int) : int =
   let b = logand b 0x7fL in
   to_int b
 
-(*$=
-  0 (popcount 0)
-  1 (popcount 1)
-  (Sys.word_size-2) (popcount max_int)
-  1 (popcount min_int)
-  10 (popcount 0b1110010110110001010)
-  5 (popcount 0b1101110000000000)
-*)
-
-(*$inject
-  let simple_popcnt i =
-    let rec loop n i =
-      if i=0 then n
-      else if i land 0b1 = 1 then loop (n+1) (i lsr 1)
-      else loop n (i lsr 1)
-    in
-    loop 0 i
-*)
-
-(*$=
-  0 (simple_popcnt 0)
-  1 (simple_popcnt 1)
-  (Sys.word_size-2) (simple_popcnt max_int)
-  1 (simple_popcnt min_int)
-  5 (simple_popcnt 0b1101110000000000)
-*)
-
-(*$QR & ~count:3_000 ~long_factor:10
-     Q.(let g = int in
-        set_gen (Gen.graft_corners g.gen [min_int; max_int; 0; -1; 1] ()) g)
-     (fun i ->
-      if simple_popcnt i <> popcount i then (
-        Q.Test.fail_reportf "on %d: simple-popcount=%d, popcount=%d"
-          i (simple_popcnt i) (popcount i)
-      );
-      true)
-    *)
-
 let logand = (land)
 
 let logor = (lor)
diff --git a/src/core/CCInt32.ml b/src/core/CCInt32.ml
index 2abe36cd..149fea02 100644
--- a/src/core/CCInt32.ml
+++ b/src/core/CCInt32.ml
@@ -24,14 +24,6 @@ let pow a b =
     | b when compare b 0l < 0 -> raise (Invalid_argument "pow: can't raise int to negative power")
     | b -> aux a b
 
-(*$T
-  pow 2l 10l = 1024l
-  pow 2l 15l = 32768l
-  pow 10l 5l = 100000l
-  pow 42l 0l = 1l
-  pow 0l 1l = 0l
-*)
-
 let floor_div a n =
   if compare a 0l < 0 && compare n 0l >= 0 then
     sub (div (add a 1l) n) 1l
@@ -40,38 +32,6 @@ let floor_div a n =
   else
     div a n
 
-(*$T
-  (floor_div 3l 5l = 0l)
-  (floor_div 5l 5l = 1l)
-  (floor_div 20l 5l = 4l)
-  (floor_div 12l 5l = 2l)
-  (floor_div 0l 5l = 0l)
-  (floor_div (-1l) 5l = -1l)
-  (floor_div (-5l) 5l = -1l)
-  (floor_div (-12l) 5l = -3l)
-
-  (floor_div 0l (-5l) = 0l)
-  (floor_div 3l (-5l) = -1l)
-  (floor_div 5l (-5l) = -1l)
-  (floor_div 9l (-5l) = -2l)
-  (floor_div 20l (-5l) = -4l)
-  (floor_div (-2l) (-5l) = 0l)
-  (floor_div (-8l) (-5l) = 1l)
-  (floor_div (-35l) (-5l) = 7l)
-
-  try ignore (floor_div 12l 0l); false with Division_by_zero -> true
-  try ignore (floor_div (-12l) 0l); false with Division_by_zero -> true
-*)
-
-(*$Q
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1l in \
-                     floor_div n m = of_float @@ floor (to_float n /. to_float m))
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1l in \
-                     floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)))
-*)
-
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 type 'a iter = ('a -> unit) -> unit
@@ -92,12 +52,6 @@ let range i j yield =
   in
   if compare i j <= 0 then up i j yield else down i j yield
 
-(*$= & ~printer:Q.Print.(list to_string)
-  [0l;1l;2l;3l;4l;5l] (range 0l 5l |> Iter.to_list)
-  [0l]                (range 0l 0l |> Iter.to_list)
-  [5l;4l;3l;2l]       (range 5l 2l |> Iter.to_list)
-*)
-
 let range' i j yield =
   if compare i j < 0 then range i (sub j 1l) yield
   else if equal i j then ()
@@ -116,29 +70,6 @@ let range_by ~step i j yield =
   else if (if compare step 0l > 0 then compare i j > 0 else compare i j < 0) then ()
   else range i (add (mul (div (sub j i) step) step) i) yield
 
-(* note: the last test checks that no error occurs due to overflows. *)
-(*$= & ~printer:Q.Print.(list to_string)
-  [0l]       (range_by ~step:1l   0l 0l      |> Iter.to_list)
-  []         (range_by ~step:1l   5l 0l      |> Iter.to_list)
-  []         (range_by ~step:2l   1l 0l      |> Iter.to_list)
-  [0l;2l;4l] (range_by ~step:2l   0l 4l      |> Iter.to_list)
-  [0l;2l;4l] (range_by ~step:2l   0l 5l      |> Iter.to_list)
-  [0l]       (range_by ~step:(neg 1l) 0l 0l  |> Iter.to_list)
-  []         (range_by ~step:(neg 1l) 0l 5l  |> Iter.to_list)
-  []         (range_by ~step:(neg 2l) 0l 1l  |> Iter.to_list)
-  [5l;3l;1l] (range_by ~step:(neg 2l) 5l 1l  |> Iter.to_list)
-  [5l;3l;1l] (range_by ~step:(neg 2l) 5l 0l  |> Iter.to_list)
-  [0l]       (range_by ~step:max_int 0l 2l   |> Iter.to_list)
-*)
-
-(*$Q
-  Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) -> \
-    let i = min i j and j = max i j in \
-    CCList.equal CCInt32.equal \
-      (CCInt32.range_by ~step:1l i j |> Iter.to_list) \
-      (CCInt32.range i j |> Iter.to_list) )
-*)
-
 let random n st = Random.State.int32 st n
 let random_small = random 100l
 let random_range i j st = add i (random (sub j i) st)
@@ -181,12 +112,6 @@ let to_string_binary n =
   to_binary_gen (Buffer.add_char buf) n;
   Buffer.contents buf
 
-(*$= & ~printer:CCFun.id
-  "0b111" (to_string_binary 7l)
-  "-0b111" (to_string_binary (-7l))
-  "0b0" (to_string_binary 0l)
-*)
-
 (** {2 Printing} *)
 
 let pp out n = Format.pp_print_string out (to_string n)
diff --git a/src/core/CCInt64.ml b/src/core/CCInt64.ml
index ab290798..1bbd1473 100644
--- a/src/core/CCInt64.ml
+++ b/src/core/CCInt64.ml
@@ -24,14 +24,6 @@ let pow a b =
     | b when compare b 0L < 0 -> raise (Invalid_argument "pow: can't raise int to negative power")
     | b -> aux a b
 
-(*$T
-  pow 2L 10L = 1024L
-  pow 2L 15L = 32768L
-  pow 10L 5L = 100000L
-  pow 42L 0L = 1L
-  pow 0L 1L = 0L
-*)
-
 let floor_div a n =
   if compare a 0L < 0 && compare n 0L >= 0 then
     sub (div (add a 1L) n) 1L
@@ -40,38 +32,6 @@ let floor_div a n =
   else
     div a n
 
-(*$T
-  (floor_div 3L 5L = 0L)
-  (floor_div 5L 5L = 1L)
-  (floor_div 20L 5L = 4L)
-  (floor_div 12L 5L = 2L)
-  (floor_div 0L 5L = 0L)
-  (floor_div (-1L) 5L = -1L)
-  (floor_div (-5L) 5L = -1L)
-  (floor_div (-12L) 5L = -3L)
-
-  (floor_div 0L (-5L) = 0L)
-  (floor_div 3L (-5L) = -1L)
-  (floor_div 5L (-5L) = -1L)
-  (floor_div 9L (-5L) = -2L)
-  (floor_div 20L (-5L) = -4L)
-  (floor_div (-2L) (-5L) = 0L)
-  (floor_div (-8L) (-5L) = 1L)
-  (floor_div (-35L) (-5L) = 7L)
-
-  try ignore (floor_div 12L 0L); false with Division_by_zero -> true
-  try ignore (floor_div (-12L) 0L); false with Division_by_zero -> true
-*)
-
-(*$Q
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1L in \
-                     floor_div n m = of_float @@ floor (to_float n /. to_float m))
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1L in \
-                     floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)))
-*)
-
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 type 'a iter = ('a -> unit) -> unit
@@ -92,12 +52,6 @@ let range i j yield =
   in
   if compare i j <= 0 then up i j yield else down i j yield
 
-(*$= & ~printer:Q.Print.(list to_string)
-  [0L;1L;2L;3L;4L;5L] (range 0L 5L |> Iter.to_list)
-  [0L]                (range 0L 0L |> Iter.to_list)
-  [5L;4L;3L;2L]       (range 5L 2L |> Iter.to_list)
-*)
-
 let range' i j yield =
   if compare i j < 0 then range i (sub j 1L) yield
   else if equal i j then ()
@@ -116,29 +70,6 @@ let range_by ~step i j yield =
   else if (if compare step 0L > 0 then compare i j > 0 else compare i j < 0) then ()
   else range i (add (mul (div (sub j i) step) step) i) yield
 
-(* note: the last test checks that no error occurs due to overflows. *)
-(*$= & ~printer:Q.Print.(list to_string)
-  [0L]       (range_by ~step:1L   0L 0L      |> Iter.to_list)
-  []         (range_by ~step:1L   5L 0L      |> Iter.to_list)
-  []         (range_by ~step:2L   1L 0L      |> Iter.to_list)
-  [0L;2L;4L] (range_by ~step:2L   0L 4L      |> Iter.to_list)
-  [0L;2L;4L] (range_by ~step:2L   0L 5L      |> Iter.to_list)
-  [0L]       (range_by ~step:(neg 1L) 0L 0L  |> Iter.to_list)
-  []         (range_by ~step:(neg 1L) 0L 5L  |> Iter.to_list)
-  []         (range_by ~step:(neg 2L) 0L 1L  |> Iter.to_list)
-  [5L;3L;1L] (range_by ~step:(neg 2L) 5L 1L  |> Iter.to_list)
-  [5L;3L;1L] (range_by ~step:(neg 2L) 5L 0L  |> Iter.to_list)
-  [0L]       (range_by ~step:max_int 0L 2L   |> Iter.to_list)
-*)
-
-(*$Q
-  Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) -> \
-    let i = min i j and j = max i j in \
-    CCList.equal CCInt64.equal \
-      (CCInt64.range_by ~step:1L i j |> Iter.to_list) \
-      (CCInt64.range i j |> Iter.to_list) )
-*)
-
 let random n st = Random.State.int64 st n
 let random_small = random 100L
 let random_range i j st = add i (random (sub j i) st)
@@ -181,12 +112,6 @@ let to_string_binary n =
   to_binary_gen (Buffer.add_char buf) n;
   Buffer.contents buf
 
-(*$= & ~printer:CCFun.id
-  "0b111" (to_string_binary 7L)
-  "-0b111" (to_string_binary (-7L))
-  "0b0" (to_string_binary 0L)
-*)
-
 (** {2 Printing} *)
 
 let pp out n = Format.pp_print_string out (to_string n)
diff --git a/src/core/CCMap.ml b/src/core/CCMap.ml
index 0ffdc293..228d7dc2 100644
--- a/src/core/CCMap.ml
+++ b/src/core/CCMap.ml
@@ -162,10 +162,6 @@ module type S = sig
       contents of the map. *)
 end
 
-(*$inject
-  module M = CCMap.Make(String)
-*)
-
 module Make(O : Map.OrderedType) = struct
   module M = Map.Make(O)
 
@@ -238,15 +234,6 @@ module Make(O : Map.OrderedType) = struct
     | None -> raise Not_found
     | Some (k,v) -> k, v
 
-  (*$= & ~printer:CCFormat.(to_string @@ Dump.(list (pair string int)))
-    ["a", 1; "b", 20] \
-      (M.of_list ["b", 2; "c", 3] \
-       |> M.update "a" (function _ -> Some 1) \
-       |> M.update "c" (fun _ -> None) \
-       |> M.update "b" (CCOption.map (fun x -> x * 10)) \
-       |> M.to_list |> List.sort CCOrd.compare)
-    *)
-
   (* === include M.
      This will shadow some values depending on OCaml's current version
      === *)
@@ -333,18 +320,3 @@ module Make(O : Map.OrderedType) = struct
       m;
     pp_stop fmt ()
 end
-
-(*$inject
-  module M2 = Make(CCInt)
-*)
-
-(*$Q
-  Q.(list (pair small_int small_int)) M2.(fun l -> \
-    to_list (of_list l) = to_list (of_list_with ~f:(fun _ v _ ->v) l))
-  Q.(list (pair small_int small_int)) M2.(fun l -> \
-   to_list (of_iter @@ Iter.of_list l) = \
-   to_list (of_iter_with ~f:(fun _ v _ ->v) @@ Iter.of_list l))
-  Q.(list (pair small_int small_int)) M2.(fun l -> \
-   to_list (of_seq @@ CCSeq.of_list l) = \
-   to_list (of_seq_with ~f:(fun _ v _ ->v) @@ CCSeq.of_list l))
-*)
diff --git a/src/core/CCNativeint.ml b/src/core/CCNativeint.ml
index 030bb811..1ca041dd 100644
--- a/src/core/CCNativeint.ml
+++ b/src/core/CCNativeint.ml
@@ -24,14 +24,6 @@ let pow a b =
     | b when compare b 0n < 0 -> raise (Invalid_argument "pow: can't raise int to negative power")
     | b -> aux a b
 
-(*$T
-  pow 2n 10n = 1024n
-  pow 2n 15n = 32768n
-  pow 10n 5n = 100000n
-  pow 42n 0n = 1n
-  pow 0n 1n = 0n
-*)
-
 let floor_div a n =
   if compare a 0n < 0 && compare n 0n >= 0 then
     sub (div (add a 1n) n) 1n
@@ -40,38 +32,6 @@ let floor_div a n =
   else
     div a n
 
-(*$T
-  (floor_div 3n 5n = 0n)
-  (floor_div 5n 5n = 1n)
-  (floor_div 20n 5n = 4n)
-  (floor_div 12n 5n = 2n)
-  (floor_div 0n 5n = 0n)
-  (floor_div (-1n) 5n = -1n)
-  (floor_div (-5n) 5n = -1n)
-  (floor_div (-12n) 5n = -3n)
-
-  (floor_div 0n (-5n) = 0n)
-  (floor_div 3n (-5n) = -1n)
-  (floor_div 5n (-5n) = -1n)
-  (floor_div 9n (-5n) = -2n)
-  (floor_div 20n (-5n) = -4n)
-  (floor_div (-2n) (-5n) = 0n)
-  (floor_div (-8n) (-5n) = 1n)
-  (floor_div (-35n) (-5n) = 7n)
-
-  try ignore (floor_div 12n 0n); false with Division_by_zero -> true
-  try ignore (floor_div (-12n) 0n); false with Division_by_zero -> true
-*)
-
-(*$Q
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1n in \
-                     floor_div n m = of_float @@ floor (to_float n /. to_float m))
-  (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) \
-      (fun (n, m) -> let m = m + 1n in \
-                     floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)))
-*)
-
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 type 'a iter = ('a -> unit) -> unit
@@ -92,12 +52,6 @@ let range i j yield =
   in
   if compare i j <= 0 then up i j yield else down i j yield
 
-(*$= & ~printer:Q.Print.(list to_string)
-  [0n;1n;2n;3n;4n;5n] (range 0n 5n |> Iter.to_list)
-  [0n]                (range 0n 0n |> Iter.to_list)
-  [5n;4n;3n;2n]       (range 5n 2n |> Iter.to_list)
-*)
-
 let range' i j yield =
   if compare i j < 0 then range i (sub j 1n) yield
   else if equal i j then ()
@@ -116,29 +70,6 @@ let range_by ~step i j yield =
   else if (if compare step 0n > 0 then compare i j > 0 else compare i j < 0) then ()
   else range i (add (mul (div (sub j i) step) step) i) yield
 
-(* note: the last test checks that no error occurs due to overflows. *)
-(*$= & ~printer:Q.Print.(list to_string)
-  [0n]       (range_by ~step:1n   0n 0n      |> Iter.to_list)
-  []         (range_by ~step:1n   5n 0n      |> Iter.to_list)
-  []         (range_by ~step:2n   1n 0n      |> Iter.to_list)
-  [0n;2n;4n] (range_by ~step:2n   0n 4n      |> Iter.to_list)
-  [0n;2n;4n] (range_by ~step:2n   0n 5n      |> Iter.to_list)
-  [0n]       (range_by ~step:(neg 1n) 0n 0n  |> Iter.to_list)
-  []         (range_by ~step:(neg 1n) 0n 5n  |> Iter.to_list)
-  []         (range_by ~step:(neg 2n) 0n 1n  |> Iter.to_list)
-  [5n;3n;1n] (range_by ~step:(neg 2n) 5n 1n  |> Iter.to_list)
-  [5n;3n;1n] (range_by ~step:(neg 2n) 5n 0n  |> Iter.to_list)
-  [0n]       (range_by ~step:max_int 0n 2n   |> Iter.to_list)
-*)
-
-(*$Q
-  Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) -> \
-    let i = min i j and j = max i j in \
-    CCList.equal CCNativeint.equal \
-      (CCNativeint.range_by ~step:1n i j |> Iter.to_list) \
-      (CCNativeint.range i j |> Iter.to_list) )
-*)
-
 let random n st = Random.State.nativeint st n
 let random_small = random 100n
 let random_range i j st = add i (random (sub j i) st)
@@ -181,12 +112,6 @@ let to_string_binary n =
   to_binary_gen (Buffer.add_char buf) n;
   Buffer.contents buf
 
-(*$= & ~printer:CCFun.id
-  "0b111" (to_string_binary 7n)
-  "-0b111" (to_string_binary (-7n))
-  "0b0" (to_string_binary 0n)
-*)
-
 (** {2 Printing} *)
 
 let pp out n = Format.pp_print_string out (to_string n)
diff --git a/src/core/CCOption.ml b/src/core/CCOption.ml
index 81a522ca..a0e9f9cc 100644
--- a/src/core/CCOption.ml
+++ b/src/core/CCOption.ml
@@ -76,12 +76,6 @@ let filter p = function
   | Some x as o when p x -> o
   | _ -> None
 
-(*$=
-  None (filter ((=) 0) (Some 1))
-  (Some 0) (filter ((=) 0) (Some 0))
-  None (filter (fun _ -> true) None)
-*)
-
 let if_ p x = if p x then Some x else None
 
 let exists p = function
@@ -116,11 +110,6 @@ let get_exn_or msg = function
   | Some x -> x
   | None -> invalid_arg msg
 
-(*$T
-  (try get_exn_or "ohno" (None:unit option); false with Invalid_argument s->s= "ohno")
-  123 = get_exn_or "yes" (Some 123)
-*)
-
 let get_lazy default_fn x = match x with
   | None -> default_fn ()
   | Some y -> y
@@ -133,12 +122,6 @@ let sequence_l l =
   in
   try aux [] l with Exit -> None
 
-(*$T
-  sequence_l [None; Some 1; Some 2] = None
-  sequence_l [Some 1; Some 2; Some 3] = Some [1;2;3]
-  sequence_l [] = Some []
-*)
-
 let wrap ?(handler=fun _ -> true) f x =
   try Some (f x)
   with e ->
@@ -211,23 +194,11 @@ let choice_iter s =
   end;
   !r
 
-(*$T
-  choice_iter (Iter.of_list [None; Some 1; Some 2]) = Some 1
-  choice_iter Iter.empty = None
-  choice_iter (Iter.repeat None |> Iter.take 100) = None
-*)
-
 let rec choice_seq s = match s() with
   | Seq.Nil -> None
   | Seq.Cons (Some x, _) -> Some x
   | Seq.Cons (None, tl) -> choice_seq tl
 
-(*$T
-  choice_seq (CCSeq.of_list [None; Some 1; Some 2]) = Some 1
-  choice_seq CCSeq.empty = None
-  choice_seq (CCSeq.repeat None |> CCSeq.take 100) = None
-*)
-
 let to_gen o =
   match o with
     | None -> (fun () -> None)
@@ -251,19 +222,8 @@ let flatten = function
   | Some x -> x
   | None -> None
 
-(*$T
-  flatten None = None
-  flatten (Some None) = None
-  flatten (Some (Some 1)) = Some 1
-*)
-
 let return_if b x =
   if b then
     Some x
   else
     None
-
-(*$T
-  return_if false 1 = None
-  return_if true 1 = Some 1
-*)
diff --git a/src/core/CCOrd.ml b/src/core/CCOrd.ml
index 9a6b8513..c2c13bd8 100644
--- a/src/core/CCOrd.ml
+++ b/src/core/CCOrd.ml
@@ -18,35 +18,11 @@ let equiv i j =
   else if i>0 then j>0
   else j=0
 
-(*$T
-  equiv 1 2
-  equiv ~-1 ~-10
-  equiv 0 0
-  equiv ~-1 ~-1
-  not (equiv 0 1)
-  not (equiv 1 ~-1)
-  not (equiv 1 0)
-*)
-
-(*$Q
-  Q.(pair int int) (fun (x,y) -> \
-    (equiv x y) = (equiv y x))
-  Q.(triple int int int) (fun (x,y,z) -> \
-    if (equiv x y && equiv y z) then (equiv x z) else true)
-*)
-
 let int (x:int) y = Stdlib.compare x y
 let string (x:string) y = Stdlib.compare x y
 let bool (x:bool) y = Stdlib.compare x y
 let float (x:float) y = Stdlib.compare x y
 
-(*$T
-  bool true false > 0
-  bool false true < 0
-  bool true true = 0
-  bool false false = 0
-*)
-
 (** {2 Lexicographic Combination} *)
 
 let (<?>) c (ord,x,y) =
@@ -60,22 +36,12 @@ let option c o1 o2 = match o1, o2 with
   | Some _, None -> 1
   | Some x1, Some x2 -> c x1 x2
 
-(*$Q
-  Q.(option int) (fun o -> option int None o <= 0)
-*)
-
 let pair o_x o_y (x1,y1) (x2,y2) =
   let c = o_x x1 x2 in
   if c = 0
   then o_y y1 y2
   else c
 
-(*$T
-  pair int string (1, "b") (2, "a") < 0
-  pair int string (1, "b") (0, "a") > 0
-  pair int string (1, "b") (1, "b") = 0
-*)
-
 let triple o_x o_y o_z (x1,y1,z1) (x2,y2,z2) =
   let c = o_x x1 x2 in
   if c = 0
@@ -96,17 +62,6 @@ let rec list ord l1 l2 = match l1, l2 with
     then list ord l1' l2'
     else c
 
-(*$T
-  list int [1;2;3] [1;2;3;4] < 0
-  list int [1;2;3;4] [1;2;3] > 0
-  list int [1;2;3;4] [1;3;4] < 0
-*)
-
-(*$Q
-  Q.(pair (list int)(list int)) CCOrd.(fun (l1,l2) -> \
-    equiv (list int l1 l2) (Stdlib.compare l1 l2))
-*)
-
 let array ord a1 a2 =
   let rec aux i =
     if i = Array.length a1
@@ -121,17 +76,6 @@ let array ord a1 a2 =
   in
   aux 0
 
-(*$T
-  array int [|1;2;3|] [|1;2;3;4|] < 0
-  array int [|1;2;3;4|] [|1;2;3|] > 0
-  array int [|1;2;3;4|] [|1;3;4|] < 0
-*)
-
-(*$Q & ~small:(fun (a1, a2) -> Array.length a1+Array.length a2)
-  Q.(pair (array int)(array int)) CCOrd.(fun (a1,a2) -> \
-    equiv (array int a1 a2) (list int (Array.to_list a1) (Array.to_list a2)))
-*)
-
 let map f ord a b = ord (f a) (f b)
 
 let (>|=) x f = map f x
diff --git a/src/core/CCParse.ml b/src/core/CCParse.ml
index 26e7eafa..72587d33 100644
--- a/src/core/CCParse.ml
+++ b/src/core/CCParse.ml
@@ -4,108 +4,6 @@
 
 open CCShims_
 
-(*$inject
-  module T = struct
-    type tree = L of int | N of tree * tree
-  end
-  open T
-
-  let mk_leaf x = L x
-  let mk_node x y = N(x,y)
-
-  let ptree = fix @@ fun self ->
-    skip_space *>
-    ( (char '(' *> (pure mk_node <*> self <*> self) <* char ')')
-      <|>
-      (U.int >|= mk_leaf) )
-
-  let ptree' = fix_memo @@ fun self ->
-    skip_space *>
-    ( (char '(' *> (pure mk_node <*> self <*> self) <* char ')')
-      <|>
-      (U.int >|= mk_leaf) )
-
-  let rec pptree = function
-    | N (a,b) -> Printf.sprintf "N (%s, %s)" (pptree a) (pptree b)
-    | L x -> Printf.sprintf "L %d" x
-
-  let errpp pp = function
-    | Ok x -> "Ok " ^ pp x
-    | Error s -> "Error " ^ s
-
-  let errpptree = errpp pptree
-
-  let erreq eq x y = match x, y with
-    | Ok x, Ok y -> eq x y
-    | Error _ , Error _ -> true
-    | _ -> false ;;
-*)
-
-(*$= & ~printer:errpptree
-  (Ok (N (L 1, N (L 2, L 3)))) \
-    (parse_string ptree "(1 (2 3))" )
-  (Ok (N (N (L 1, L 2), N (L 3, N (L 4, L 5))))) \
-    (parse_string ptree "((1 2) (3 (4 5)))" )
-  (Ok (N (L 1, N (L 2, L 3)))) \
-    (parse_string ptree' "(1 (2 3))" )
-  (Ok (N (N (L 1, L 2), N (L 3, N (L 4, L 5))))) \
-    (parse_string ptree' "((1 2) (3 (4 5)))" )
-*)
-
-(*$R
-  let p = U.list ~sep:"," U.word in
-  let printer = function
-    | Ok l -> "Ok " ^ CCFormat.(to_string (Dump.list string_quoted)) l
-    | Error s -> "Error " ^ s
-  in
-  assert_equal ~printer
-    (Ok ["abc"; "de"; "hello"; "world"])
-    (parse_string p "[abc , de, hello ,world  ]");
-*)
-
-(*$R
-  let test n =
-    let p = CCParse.(U.list ~sep:"," U.int) in
-
-    let l = CCList.(1 -- n) in
-    let l_printed =
-      CCFormat.(to_string (within "[" "]" (list ~sep:(return ",") int))) l in
-
-    let l' = CCParse.parse_string_exn p l_printed in
-
-    assert_equal ~printer:Q.Print.(list int) l l'
-  in
-  test 300_000;
-
-*)
-
-(*$R
-  let open CCParse.Infix in
-  let module P = CCParse in
-
-  let parens p = P.char '(' *> p <* P.char ')' in
-  let add = P.char '+' *> P.return (+) in
-  let sub = P.char '-' *> P.return (-) in
-  let mul = P.char '*' *> P.return ( * ) in
-  let div = P.char '/' *> P.return ( / ) in
-  let integer =
-  P.chars1_if (function '0'..'9'->true|_->false) >|= int_of_string in
-
-  let chainr1 e op =
-  P.fix (fun r ->
-    e >>= fun x -> (op <*> P.return x <*> r) <|> P.return x) in
-
-  let expr : int P.t =
-  P.fix (fun expr ->
-    let factor = parens expr <|> integer in
-    let term = chainr1 factor (mul <|> div) in
-    chainr1 term (add <|> sub)) in
-
-  assert_equal (Ok 6) (P.parse_string expr "4*1+2");
-  assert_equal (Ok 12) (P.parse_string expr "4*(1+2)");
-  ()
-*)
-
 module Memo_tbl = Hashtbl.Make(struct
     type t = int * int  (* id of parser, position *)
     let equal ((a,b):t)(c,d) = a=c && b=d
@@ -381,12 +279,6 @@ let eoi = {
   else err (mk_error_ st (const_str_ "expected end of input"))
 }
 
-(*$= & ~printer:(errpp Q.Print.bool) ~cmp:(erreq (=))
-  (Ok true) (parse_string (U.bool <* eoi) "true")
-  (Error "") (parse_string (U.bool <* eoi) "true ")
-  (Ok true) (parse_string (U.bool <* skip_white <* eoi) "true")
-*)
-
 let with_pos p : _ t = {
   run=fun st ~ok ~err ->
     p.run st
@@ -399,21 +291,6 @@ let pos : _ t = {
   run=fun st ~ok ~err:_ -> ok st (pos_of_st_ st)
 }
 
-(*$= & ~printer:Q.Print.(pair int int)
-  (0,5) (let p = any_char_n 5 *> pos in \
-  match parse_string p "abcde   " with \
-    | Ok p -> Position.line_and_column p \
-    | Error _ -> assert false)
-*)
-
-(*$= & ~printer:Q.Print.(list @@ pair int int)
-  [(0,2); (1,3); (2,1); (3,0); (4,0); (5,2)] \
-   (let p = each_line (skip_space *> pos) in \
-    match parse_string p "  a\n  b\nc\n\n\n a" with \
-      | Ok ps -> List.map Position.line_and_column ps \
-      | Error _ -> assert false)
-*)
-
 (* a slice is just a state, which makes {!recurse} quite easy. *)
 type slice = state
 
@@ -443,16 +320,6 @@ let all = {
 
 let all_str = all >|= Slice.to_string
 
-(*$= & ~printer:(errpp Q.Print.string) ~cmp:(erreq (=))
-  (Ok "abcd") (parse_string all_str "abcd")
-  (Ok "cd") (parse_string (string "ab" *> all_str) "abcd")
-  (Ok "") (parse_string (string "ab" *> all_str) "ab")
-*)
-
-(*$= & ~printer:(errpp Q.Print.(pair string string)) ~cmp:(erreq (=))
-  (Ok ("foobar", "")) (parse_string (both all_str all_str) "foobar")
-  *)
-
 let fail msg : _ t = {
   run=fun st ~ok:_ ~err ->
     err (mk_error_ st (const_str_ msg))
@@ -559,19 +426,6 @@ let chars1_if ?descr p = {
       ~err
 }
 
-(*$QR
-    Q.(printable_string) (fun s ->
-        let pred = (function 'a'..'z' | 'A' .. 'Z' | '{' | '}' -> true | _ -> false) in
-        let p1 = chars1_if pred in
-        let p2 = take1_if pred >|= Slice.to_string in
-        parse_string p1 s = parse_string p2 s)
-    *)
-
-(*$T
-  let pred = (function 'a'..'z' | 'A' .. 'Z' | '{' | '}' -> true | _ -> false) in \
-  parse_string (chars_if pred) "coucou{lol} 123" = Ok "coucou{lol}"
-*)
-
 exception Fold_fail of state * string
 
 let chars_fold ~f acc0 = {
@@ -787,16 +641,6 @@ let many p : _ t = {
 }
    *)
 
-(*$R
-  let p0 = skip_white *> U.int in
-  let p = (skip_white *> char '(' *> many p0) <* (skip_white <* char ')') in
-  let printer =  CCFormat.(to_string @@ Dump.result  @@ Dump.list int) in
-  assert_equal ~printer
-    (Ok [1;2;3]) (parse_string p "(1 2 3)");
-  assert_equal ~printer
-    (Ok [1;2; -30; 4]) (parse_string p "( 1 2    -30 4 )")
-  *)
-
 
 let many1 p =
   p >>= fun x ->
@@ -836,16 +680,6 @@ let sep ~by p =
   ) in
   Lazy.force read_p
 
-(*$inject
-  let aword = chars1_if (function 'a'..'z'|'A'..'Z'->true|_ -> false);;
-*)
-(*$= & ~printer:(errpp Q.Print.(list string))
-(Ok ["a";"b";"c"]) \
-  (parse_string (optional (char '/') *> sep ~by:(char '/') aword) "/a/b/c")
-(Ok ["a";"b";"c"]) \
-  (parse_string (optional (char '/') *> sep ~by:(char '/') aword) "a/b/c")
-*)
-
 let sep1 ~by p =
   p >>= fun x ->
   sep ~by p >|= fun tl ->
@@ -871,18 +705,6 @@ let set_current_slice sl : _ t = {
     ok sl () (* jump to slice *)
 }
 
-(*$= & ~printer:(errpp Q.Print.(string))
-  (Ok "abc") (parse_string (lookahead (string "ab") *> (string "abc")) "abcd")
-*)
-
-(*$= & ~printer:(errpp Q.Print.(string))
-  (Ok "1234") (parse_string line_str "1234\nyolo")
-  *)
-
-(*$= & ~printer:(errpp Q.Print.(pair String.escaped String.escaped))
-  (Ok ("1234", "yolo")) (parse_string (line_str ||| line_str) "1234\nyolo\nswag")
-*)
-
 let split_1 ~on_char : _ t = {
   run=fun st ~ok ~err:_ ->
     if st.i >= st.j then (
@@ -922,13 +744,6 @@ let split_list_at_most ~on_char n : slice list t =
   in
   loop [] n
 
-(*$= & ~printer:(errpp Q.Print.(list string)) ~cmp:(erreq (=))
-  (Ok ["a";"b";"c";"d,e,f"]) \
-    (parse_string (split_list_at_most ~on_char:',' 3 >|= List.map Slice.to_string) "a,b,c,d,e,f")
-  (Ok ["a";"bc"]) \
-    (parse_string (split_list_at_most ~on_char:',' 3 >|= List.map Slice.to_string) "a,bc")
-*)
-
 let split_list ~on_char : _ t =
   split_list_at_most ~on_char max_int
 
@@ -986,11 +801,6 @@ let line_str = line >|= Slice.to_string
 let each_line p : _ t =
   each_split ~on_char:'\n' p
 
-(*$= & ~printer:(errpp Q.Print.(list @@ list int))
-  (Ok ([[1;1];[2;2];[3;3];[]])) \
-    (parse_string (each_line (sep ~by:skip_space U.int)) "1 1\n2 2\n3   3\n")
-*)
-
 let memo (type a) (p:a t) : a t =
   let id = !Memo_state.id_ in
   incr Memo_state.id_;
@@ -1094,13 +904,6 @@ module U = struct
     try return (int_of_string s)
     with Failure _ -> fail "expected an int"
 
-  (*$= & ~printer:(errpp Q.Print.int) ~cmp:(erreq (=))
-    (Ok 42) (parse_string U.int " 42")
-    (Ok 2) (parse_string U.int "2")
-    (Error "") (parse_string U.int "abc")
-    (Error "") (parse_string U.int "")
-  *)
-
   let in_paren (p:'a t) : 'a t =
     skip_white *>
     (char '(' *> skip_white *> p <* skip_white <* char ')')
@@ -1113,16 +916,6 @@ module U = struct
         ~f:(fun _ -> skip_white *> self <* skip_white <* char ')')
         ~else_:p)
 
-  (*$= & ~printer:(errpp Q.Print.int) ~cmp:(erreq (=))
-    (Ok 15) (parse_string (U.in_paren (U.in_paren U.int)) "( ( 15) )")
-    (Ok 2) (parse_string (U.in_paren U.int) "(2)")
-    (Error "") (parse_string (U.in_paren U.int) "2")
-    (Error "") (parse_string (U.in_paren U.int) "")
-    (Ok 2) (parse_string (U.in_parens_opt U.int) "((((2))))")
-    (Ok 2) (parse_string (U.in_parens_opt U.int) "2")
-    (Ok 200) (parse_string (U.in_parens_opt U.int) "( (  200 ) )")
-  *)
-
   let option p =
     skip_white *>
     try_or
@@ -1130,13 +923,6 @@ module U = struct
       ~f:(fun _ -> skip_white *> p >|= fun x -> Some x)
       ~else_:(string "None" *> return None)
 
-  (*$= & ~printer:(errpp Q.Print.(option int)) ~cmp:(erreq (=))
-    (Ok (Some 12)) (parse_string U.(option int) " Some 12")
-    (Ok None) (parse_string U.(option int) "  None")
-    (Ok (Some 0)) (parse_string U.(option int) "Some 0")
-    (Ok (Some 0)) (parse_string U.(in_parens_opt @@ option int) "(( Some 0) )")
-  *)
-
   let hexa_int =
     (exact "0x" <|> return "") *>
     begin
@@ -1156,13 +942,6 @@ module U = struct
       !i
     end
 
-  (*$= & ~printer:(errpp Q.Print.int) ~cmp:(erreq (=))
-    (Ok 16) (parse_string U.hexa_int "0x10")
-    (Ok 16) (parse_string U.hexa_int "10")
-    (Error "") (parse_string U.hexa_int "x10")
-    (Error "") (parse_string U.hexa_int "0xz")
-  *)
-
   let prepend_str c s = String.make 1 c ^ s
 
   let word =
@@ -1171,10 +950,6 @@ module U = struct
   let bool =
     skip_white *>
     ((string "true" *> return true) <|> (string "false" *> return false))
-  (*$= & ~printer:(errpp Q.Print.bool) ~cmp:(erreq (=))
-    (Ok true) (parse_string U.bool "true")
-    (Ok false) (parse_string U.bool "false")
-    *)
 
   let pair ?(start="(") ?(stop=")") ?(sep=",") p1 p2 =
     skip_white *> string start *> skip_white *>
@@ -1183,10 +958,6 @@ module U = struct
       p2 >>= fun x2 ->
     skip_white *> string stop *> return (x1,x2)
 
-  (*$= & ~printer:Q.Print.(errpp (pair int int))
-    (Ok(1,2)) U.(parse_string (pair int int) "(1 , 2 )")
-  *)
-
   let triple ?(start="(") ?(stop=")") ?(sep=",") p1 p2 p3 =
     string start *> skip_white *>
       p1 >>= fun x1 ->
diff --git a/src/core/CCRandom.ml b/src/core/CCRandom.ml
index c1567b65..2618f8fd 100644
--- a/src/core/CCRandom.ml
+++ b/src/core/CCRandom.ml
@@ -47,11 +47,6 @@ let pick_list l =
   fun st ->
     List.nth l (Random.State.int st n)
 
-(*$Q
-  Q.(list small_int) (fun l -> \
-    l=[] || List.mem (run (pick_list l)) l)
-*)
-
 let pick_array a =
   let n = Array.length a in
   if n=0 then raise Pick_from_empty;
@@ -123,13 +118,6 @@ let split_list i ~len st =
   ) else
     None
 
-(*$Q
-  Q.(pair small_int small_int) (fun (i,j) -> \
-    let len, n = 2+min i j, max i j in \
-    let l = QCheck.Gen.generate1 (split_list n ~len) in \
-    match l with None -> true | Some l -> l<> [] && List.for_all (fun x->x>0) l)
-*)
-
 let retry ?(max=10) g st =
   let rec aux n =
     match g st with
@@ -208,8 +196,3 @@ let (and*) = (and+)
 let __default_state = Random.State.make_self_init ()
 
 let run ?(st=__default_state) g = g st
-
-(*$R
-  let open Containers in
-  ignore @@ List.random_choose [1;2;3] (Random.get_state())
-*)
diff --git a/src/core/CCResult.ml b/src/core/CCResult.ml
index 469c143a..12a35e7a 100644
--- a/src/core/CCResult.ml
+++ b/src/core/CCResult.ml
@@ -27,10 +27,6 @@ let fail_printf format =
     (fun buf -> fail (Buffer.contents buf))
     buf format
 
-(*$T
-  (Error "ohno 42") = (fail_printf "ohno %d" 42)
-*)
-
 let fail_fprintf format =
   let buf = Buffer.create 64 in
   let out = Format.formatter_of_buffer buf in
@@ -38,10 +34,6 @@ let fail_fprintf format =
     (fun out -> Format.pp_print_flush out (); fail (Buffer.contents buf))
     out format
 
-(*$T
-  (Error "ohno 42") = (fail_fprintf "ohno %d" 42)
-*)
-
 let add_ctx msg x = match x with
   | Error e -> Error (e ^ "\ncontext:" ^ msg)
   | Ok x -> Ok x
@@ -53,11 +45,6 @@ let add_ctxf msg =
     (fun out e -> Format.pp_print_flush out (); add_ctx (Buffer.contents buf) e)
     out msg
 
-(*$=
-   (Error "error\ncontext:message(number 42, foo: true)") \
-     (add_ctxf "message(number %d, foo: %B)" 42 true (Error "error"))
-*)
-
 let of_exn e =
   let msg = Printexc.to_string e in
   Error msg
@@ -96,15 +83,6 @@ let iter_err f e = match e with
   | Ok _ -> ()
   | Error err -> f err
 
-(*$R iter_err
-  let called_with = ref None in
-  let f e = called_with := Some e in
-  iter_err f (Ok 1);
-  assert_bool "should not apply when Ok" (!called_with = None);
-  iter_err f (Error 1);
-  assert_bool "should apply f to Error" (!called_with = Some 1)
-*)
-
 exception Get_error
 
 let get_exn = function
@@ -123,20 +101,10 @@ let get_or_failwith = function
   | Ok x -> x
   | Error msg -> failwith msg
 
-(*$T
-  get_or_failwith (Ok 1) = 1
-  try ignore @@ get_or_failwith (Error "e"); false with Failure msg -> msg = "e"
-*)
-
 let get_lazy default_fn x = match x with
   | Ok x -> x
   | Error e -> default_fn e
 
-(*$= get_lazy
-  (get_lazy (fun _ -> 2) (Ok 1)) (1)
-  (get_lazy (fun _ -> 2) (Error "error")) (2)
-*)
-
 let map_or f e ~default = match e with
   | Ok x -> f x
   | Error _ -> default
@@ -168,11 +136,6 @@ let fold_ok f acc r = match r with
   | Ok x -> f acc x
   | Error _ -> acc
 
-(*$=
-  42 (fold_ok (+) 2 (Ok 40))
-  40 (fold_ok (+) 40 (Error "foo"))
-*)
-
 let is_ok = function
   | Ok _ -> true
   | Error _ -> false
@@ -243,12 +206,6 @@ let flatten_l l =
     | Error e::_ -> Error e
   in loop [] l
 
-(*$=
-  (Ok []) (flatten_l [])
-  (Ok [1;2;3]) (flatten_l [Ok 1; Ok 2; Ok 3])
-  (Error "ohno") (flatten_l [Ok 1; Error "ohno"; Ok 2; Ok 3; Error "wut"])
-*)
-
 exception LocalExit
 
 let fold_iter f acc seq =
diff --git a/src/core/CCSeq.ml b/src/core/CCSeq.ml
index b911caeb..1a9e68d6 100644
--- a/src/core/CCSeq.ml
+++ b/src/core/CCSeq.ml
@@ -27,12 +27,6 @@ let repeat ?n x = match n with
   | None -> _forever x
   | Some n -> _repeat n x
 
-(*$T
-  repeat ~n:4 0 |> to_list = [0;0;0;0]
-  repeat ~n:0 1 |> to_list = []
-  repeat 1 |> take 20 |> to_list = (repeat ~n:20 1 |> to_list)
-*)
-
 let is_empty l = match l () with
   | Nil -> true
   | Cons _ -> false
@@ -89,10 +83,6 @@ let rec take_while p l () = match l () with
   | Cons (x,l') ->
     if p x then Cons (x, take_while p l') else Nil
 
-(*$T
-  of_list [1;2;3;4] |> take_while (fun x->x < 4) |> to_list = [1;2;3]
-*)
-
 let rec drop n (l:'a t) () = match l () with
   | l' when n=0 -> l'
   | Nil -> Nil
@@ -103,20 +93,10 @@ let rec drop_while p l () = match l() with
   | Cons (x,l') when p x -> drop_while p l' ()
   | Cons _ as res -> res
 
-(*$Q
-  (Q.pair (Q.list Q.small_int) Q.small_int) (fun (l,n) -> \
-    let s = of_list l in let s1, s2 = take n s, drop n s in \
-    append s1 s2 |> to_list = l  )
-*)
-
 let rec map f l () = match l () with
   | Nil -> Nil
   | Cons (x, l') -> Cons (f x, map f l')
 
-(*$T
-  (map ((+) 1) (1 -- 5) |> to_list) = (2 -- 6 |> to_list)
-*)
-
 let mapi f l =
   let rec aux f l i () = match l() with
     | Nil -> Nil
@@ -125,10 +105,6 @@ let mapi f l =
   in
   aux f l 0
 
-(*$T
-  mapi (fun i x -> i,x) (1 -- 3) |> to_list = [0, 1; 1, 2; 2, 3]
-*)
-
 let rec fmap f (l:'a t) () = match l() with
   | Nil -> Nil
   | Cons (x, l') ->
@@ -137,11 +113,6 @@ let rec fmap f (l:'a t) () = match l() with
       | Some y -> Cons (y, fmap f l')
     end
 
-(*$T
-  fmap (fun x -> if x mod 2=0 then Some (x*3) else None) (1--10) |> to_list \
-    = [6;12;18;24;30]
-*)
-
 let rec filter p l () = match l () with
   | Nil -> Nil
   | Cons (x, l') ->
@@ -155,54 +126,20 @@ let rec append l1 l2 () = match l1 () with
 
 let rec cycle l () = append l (cycle l) ()
 
-(*$T
-  cycle (of_list [1;2]) |> take 5 |> to_list = [1;2;1;2;1]
-  cycle (of_list [1; ~-1]) |> take 100_000 |> fold (+) 0 = 0
-*)
-
 let rec unfold f acc () = match f acc with
   | None -> Nil
   | Some (x, acc') -> Cons (x, unfold f acc')
 
-(*$T
-  let f = function  10 -> None | x -> Some (x, x+1) in \
-  unfold f 0 |> to_list = [0;1;2;3;4;5;6;7;8;9]
-*)
-
 let rec for_all p l =
   match l () with
   | Nil -> true
   | Cons (x, tl) -> p x && for_all p tl
 
-(*$T
-  for_all ((=) 1) (of_list []) = true
-  for_all ((=) 1) (of_list [0]) = false
-  for_all ((=) 1) (of_list [1]) = true
-  for_all ((=) 1) (of_list [1; 0]) = false
-  for_all ((=) 1) (of_list [0; 1]) = false
-  for_all ((=) 1) (of_list [1; 1]) = true
-
-  let l () = Cons (0, fun () -> failwith "no second element") in \
-  try ignore (for_all ((=) 1) l); true with Failure _ -> false
-*)
-
 let rec exists p l =
   match l () with
   | Nil -> false
   | Cons (x, tl) -> p x || exists p tl
 
-(*$T
-  exists ((=) 1) (of_list []) = false
-  exists ((=) 1) (of_list [0]) = false
-  exists ((=) 1) (of_list [1]) = true
-  exists ((=) 1) (of_list [1; 0]) = true
-  exists ((=) 1) (of_list [0; 1]) = true
-  exists ((=) 1) (of_list [0; 0]) = false
-
-  let l () = Cons (1, fun () -> failwith "no second element") in \
-  try ignore (exists ((=) 1) l); true with Failure _ -> false
-*)
-
 let rec flat_map f l () = match l () with
   | Nil -> Nil
   | Cons (x, l') ->
@@ -245,11 +182,6 @@ let rec group eq l () = match l() with
   | Cons (x, l') ->
     Cons (cons x (take_while (eq x) l'), group eq (drop_while (eq x) l'))
 
-(*$T
-  of_list [1;1;1;2;2;3;3;1] |> group (=) |> map to_list |> to_list = \
-    [[1;1;1]; [2;2]; [3;3]; [1]]
-*)
-
 let rec _uniq eq prev l () = match prev, l() with
   | _, Nil -> Nil
   | None, Cons (x, l') ->
@@ -278,12 +210,6 @@ let range i j =
     else Cons (i, aux (i-1) j)
   in aux i j
 
-(*$T
-  range 0 5 |> to_list = [0;1;2;3;4;5]
-  range 0 0 |> to_list = [0]
-  range 5 2 |> to_list = [5;4;3;2]
-*)
-
 let (--) = range
 
 let (--^) i j =
@@ -291,13 +217,6 @@ let (--^) i j =
   else if i<j then range i (j-1)
   else range i (j+1)
 
-(*$T
-  1 --^ 5 |> to_list = [1;2;3;4]
-  5 --^ 1 |> to_list = [5;4;3;2]
-  1 --^ 2 |> to_list = [1]
-  0 --^ 0 |> to_list = []
-*)
-
 let rec fold2 f acc l1 l2 = match l1(), l2() with
   | Nil, _
   | _, Nil -> acc
@@ -351,11 +270,6 @@ let unzip l =
   in
   first l, second l
 
-(*$Q
-  Q.(list (pair int int)) (fun l -> \
-    let l = of_list l in let a, b = unzip l in equal (=) l (zip a b))
-*)
-
 let zip_i seq =
   let rec loop i seq () = match seq() with
     | Nil -> Nil
@@ -363,10 +277,6 @@ let zip_i seq =
   in
   loop 0 seq
 
-(*$=
-  [0,'a'; 1, 'b'; 2, 'c'] (of_string "abcde" |> zip_i |> take 3 |> to_list)
-*)
-
 (** {2 Implementations} *)
 
 let return x () = Cons (x, nil)
@@ -428,18 +338,6 @@ let to_array l =
       ignore (List.fold_left (fun i x -> a.(i) <- x; i - 1) idx rest : int);
       a
 
-(*$Q
-   Q.(array int) (fun a -> of_array a |> to_array = a)
-*)
-
-(*$T
-  of_array [| 1; 2; 3 |] |> to_list = [1;2;3]
-  of_list [1;2;3] |> to_array = [| 1; 2; 3; |]
-  let r = ref 1 in \
-  let s = unfold (fun i -> if i < 3 then let x = !r in incr r; Some (x, succ i) else None) 0 in \
-  to_array s = [| 1; 2; 3; |]
-*)
-
 let rec to_iter res k = match res () with
   | Nil -> ()
   | Cons (s, f) -> k s; to_iter f k
@@ -474,14 +372,6 @@ let of_gen g =
   in
   consume (ref (Of_gen_thunk g))
 
-(*$R
-  let g = let n = ref 0 in fun () -> Some (incr n; !n) in
-  let l = of_gen g in
-  assert_equal [1;2;3;4;5;6;7;8;9;10] (take 10 l |> to_list);
-  assert_equal [1;2;3;4;5;6;7;8;9;10] (take 10 l |> to_list);
-  assert_equal [11;12] (drop 10 l |> take 2 |> to_list);
-*)
-
 let sort ~cmp l =
   let l = to_list l in
   of_list (List.sort cmp l)
@@ -506,20 +396,6 @@ let rec memoize f =
       r := MemoSave l;
       l
 
-(*$R
-  let printer = Q.Print.(list int) in
-  let gen () =
-    let rec l = let r = ref 0 in fun () -> incr r; Cons (!r, l) in l
-  in
-  let l1 = gen () in
-  assert_equal ~printer [1;2;3;4] (take 4 l1 |> to_list);
-  assert_equal ~printer [5;6;7;8] (take 4 l1 |> to_list);
-  let l2 = gen () |> memoize in
-  assert_equal ~printer [1;2;3;4] (take 4 l2 |> to_list);
-  assert_equal ~printer [1;2;3;4] (take 4 l2 |> to_list);
-*)
-
-
 (** {2 Fair Combinations} *)
 
 let rec interleave a b () = match a() with
@@ -540,12 +416,6 @@ let rec fair_app f a () = match f() with
 let (>>-) a f = fair_flat_map f a
 let (<.>) f a = fair_app f a
 
-(*$T
-  interleave (of_list [1;3;5]) (of_list [2;4;6]) |> to_list = [1;2;3;4;5;6]
-  fair_app (of_list [(+)1; ( * ) 3]) (of_list [1; 10]) \
-    |> to_list |> List.sort Stdlib.compare = [2; 3; 11; 30]
-*)
-
 (** {2 Infix} *)
 
 module Infix = struct
diff --git a/src/core/CCSet.ml b/src/core/CCSet.ml
index 16f17ea1..47e18616 100644
--- a/src/core/CCSet.ml
+++ b/src/core/CCSet.ml
@@ -8,13 +8,6 @@ type 'a printer = Format.formatter -> 'a -> unit
 
 module type OrderedType = Set.OrderedType
 
-(*$inject
-  module S = CCSet.Make(struct
-    type t = int
-    let compare x y = Stdlib.compare x y
-  end)
-*)
-
 module type S = sig
   include Set.S
 
@@ -165,22 +158,6 @@ module Make(O : Map.OrderedType) = struct
     to_list h
     |> CCList.to_string ~start ~stop ~sep elt_to_string
 
-  (*$= & ~printer:(fun s -> s)
-    (S.to_string string_of_int (S.of_list [4; 3])) "3,4"
-  *)
-  (*$Q
-    Q.(list int) (fun l -> \
-      let s = S.of_list l in \
-      (S.to_string string_of_int s) \
-        = (CCList.sort_uniq ~cmp:CCInt.compare l \
-           |> List.map string_of_int |> String.concat ","))
-    Q.(list int) (fun l -> \
-      let s = S.of_list l in \
-      (S.to_string ~sep:" " string_of_int s) \
-        = (CCList.sort_uniq ~cmp:CCInt.compare l \
-           |> List.map string_of_int |> String.concat " "))
-  *)
-
   let pp ?(pp_start=fun _ () -> ()) ?(pp_stop=fun _ () -> ())
       ?(pp_sep=fun fmt () -> Format.fprintf fmt ",@ ") pp_x fmt m =
     pp_start fmt ();
diff --git a/src/core/CCSexp.ml b/src/core/CCSexp.ml
index e4fb37ba..c1e6234a 100644
--- a/src/core/CCSexp.ml
+++ b/src/core/CCSexp.ml
@@ -347,92 +347,4 @@ end
 
 include (Make(Basic_) : S with type t := t and type loc = unit)
 
-(*$T
-  CCResult.to_opt (parse_string "(abc d/e/f \"hello \\\" () world\" )") <> None
-  CCResult.to_opt (parse_string "(abc ( d e ffff   ) \"hello/world\")") <> None
-  CCResult.to_opt (parse_string "\"\123\bcoucou\"") <> None
-*)
-
-(*$= & ~printer:(function Ok x -> to_string x | Error e -> "error " ^ e)
-  (parse_string "(a b)") (Ok (`List [`Atom "a"; `Atom "b"]))
-  (parse_string "(a\n ;coucou\n b)") (Ok (`List [`Atom "a"; `Atom "b"]))
-  (parse_string "(a #; (foo bar\n (1 2 3)) b)") (Ok (`List [`Atom "a"; `Atom "b"]))
-  (parse_string "#; (a b) (c d)") (Ok (`List [`Atom "c"; `Atom "d"]))
-  (parse_string "#; (a b) 1") (Ok (`Atom "1"))
-*)
-
-(*$= & ~printer:(function Ok x -> String.concat ";" @@ List.map to_string x | Error e -> "error " ^ e)
-  (parse_string_list "(a b)(c)") (Ok [`List [`Atom "a"; `Atom "b"]; `List [`Atom "c"]])
-  (parse_string_list "  ") (Ok [])
-  (parse_string_list "(a\n ;coucou\n b)") (Ok [`List [`Atom "a"; `Atom "b"]])
-  (parse_string_list "#; (a b) (c d) e ") (Ok [`List [`Atom "c"; `Atom "d"]; `Atom "e"])
-  (parse_string_list "#; (a b) 1") (Ok [`Atom "1"])
-*)
-
-
-(*$inject
-  let sexp_bijective s = to_string s |> parse_string = Ok s
-*)
-
-(*$= & ~printer:CCFormat.(to_string (Dump.result pp))
-  (Ok (`List [`Atom ""])) (parse_string "(\"\")")
-*)
-
-(*$T
-  sexp_bijective (`List [`Atom ""])
-*)
-
-(*$inject
-  let sexp_gen =
-    let mkatom a = `Atom a and mklist l = `List l in
-    let atom = Q.Gen.(map mkatom (string_size ~gen:printable (1 -- 30))) in
-    let gen = Q.Gen.(
-      sized (fix
-        (fun self n st -> match n with
-        | 0 -> atom st
-        | _ ->
-          frequency
-            [ 1, atom
-            ; 2, map mklist (list_size (0 -- 10) (self (n/10)))
-            ] st
-        )
-    )) in
-    let rec small = function
-      | `Atom s -> String.length s
-      |  `List l -> List.fold_left (fun n x->n+small x) 0 l
-    and print = function
-      | `Atom s -> Printf.sprintf "`Atom \"%s\"" s
-      | `List l -> "`List " ^ Q.Print.list print l
-    and shrink = function
-      | `Atom s -> Q.Iter.map mkatom (Q.Shrink.string s)
-      | `List l -> Q.Iter.map mklist (Q.Shrink.list ~shrink l)
-    in
-    Q.make ~print ~small ~shrink gen
-*)
-
-(*$Q & ~count:100
-    sexp_gen sexp_bijective
-*)
-
 let atom s : t = `Atom s
-
-(* regression for #338 *)
-(*$R
-  Printexc.record_backtrace true;
-  let cases = [
-    "\"\\256\"";
-    "\"\\722\02622222\\\\\n\r<\\\\\\\\\"\\222222222\\\\\"\"\2032!2222\\\\\"\"";
-    "\"\n\r<\\t\023\n\203\\622222222\\\\\"\"\2032!2222\\\\\"\"";
-    "\"\n\r<@t\023\n\203\\2222D2\n\r22222\01622222222222222222222222\203\\292242\222 2\\\\\">K2";
-    "\"\n\r<\\t\023\n\203\\272222222\\\\\"\"\2032\0042222\\\\\"\"";
-    "\"\023\n\203\\5222\n\r<\\t\023\n\203\\52222222\\\\\"2\\\216\216\216\216\216\\\\\"\216\216\216\216\216\216\216\216\216222222222222222\147";
-    "\"\\722\02622222\\\\\n\r<\\\\\\\\\"\\222222222\\\\\"\"\2032!2222\\\\\"\"";
-  ] in
-  cases
-  |> List.iter (fun s ->
-    try ignore (parse_string s);
-    with e ->
-      let st = Printexc.get_backtrace() in
-      print_endline @@ Printexc.to_string e ^ "\n" ^ st;
-      assert false)
-*)
diff --git a/src/core/CCString.ml b/src/core/CCString.ml
index aab63806..facf7da0 100644
--- a/src/core/CCString.ml
+++ b/src/core/CCString.ml
@@ -3,10 +3,6 @@
 
 (** {1 Basic String Utils} *)
 
-(*$inject
-  open CCShims_.Stdlib
-*)
-
 open CCShims_
 
 type 'a iter = ('a -> unit) -> unit
@@ -29,23 +25,6 @@ let rev s =
   let n = length s in
   init n (fun i -> s.[n-i-1])
 
-(*$Q
-  Q.printable_string (fun s -> s = rev (rev s))
-  Q.printable_string (fun s -> length s = length (rev s))
-*)
-
-(*$Q
-  Q.printable_string (fun s -> \
-    rev s = (to_list s |> List.rev |> of_list))
-*)
-
-
-(*$=
-  "abc" (rev "cba")
-  "" (rev "")
-  " " (rev " ")
-*)
-
 let rec _to_list s acc i len =
   if len=0 then List.rev acc
   else _to_list s (s.[i]::acc) (i+1) (len-1)
@@ -234,19 +213,6 @@ let find ?(start=0) ~sub =
   let pattern = Find.compile sub in
   fun s -> Find.find ~start ~pattern s
 
-(*$= & ~printer:string_of_int
-  1 (find ~sub:"bc" "abcd")
-  ~-1 (find ~sub:"bc" "abd")
-  1 (find ~sub:"a" "_a_a_a_")
-  6 (find ~start:5 ~sub:"a" "a1a234a")
-*)
-
-(*$Q & ~count:10_000
-  Q.(pair printable_string printable_string) (fun (s1,s2) -> \
-    let i = find ~sub:s2 s1 in \
-    i < 0 || String.sub s1 i (length s2) = s2)
-*)
-
 let find_all ?(start=0) ~sub =
   let pattern = Find.compile sub in
   fun s ->
@@ -266,38 +232,12 @@ let find_all_l ?start ~sub s =
   in
   aux [] (find_all ?start ~sub s)
 
-(*$= & ~printer:Q.Print.(list int)
-  [1; 6] (find_all_l ~sub:"bc" "abc aabc  aab")
-  [] (find_all_l ~sub:"bc" "abd")
-  [76] (find_all_l ~sub:"aaaaaa" \
-    "aabbaabbaaaaabbbbabababababbbbabbbabbaaababbbaaabaabbaabbaaaabbababaaaabbaabaaaaaabbbaaaabababaabaaabbaabaaaabbababbaabbaaabaabbabababbbaabababaaabaaababbbaaaabbbaabaaababbabaababbaabbaaaaabababbabaababbbaaabbabbabababaaaabaaababaaaaabbabbaabbabbbbbbbbbbbbbbaabbabbbbbabbaaabbabbbbabaaaaabbababbbaaaa")
-*)
-
 let mem ?start ~sub s = find ?start ~sub s >= 0
 
-(*$T
-   mem ~sub:"bc" "abcd"
-   not (mem ~sub:"a b" "abcd")
-*)
-
 let rfind ~sub =
   let pattern = Find.rcompile sub in
   fun s -> Find.rfind ~start:(String.length s-1) ~pattern s
 
-(*$= & ~printer:string_of_int
-  1 (rfind ~sub:"bc" "abcd")
-  ~-1 (rfind ~sub:"bc" "abd")
-  5 (rfind ~sub:"a" "_a_a_a_")
-  4 (rfind ~sub:"bc" "abcdbcd")
-  6 (rfind ~sub:"a" "a1a234a")
-*)
-
-(*$Q & ~count:10_000
-  Q.(pair printable_string printable_string) (fun (s1,s2) -> \
-    let i = rfind ~sub:s2 s1 in \
-    i < 0 || String.sub s1 i (length s2) = s2)
-*)
-
 (* Replace substring [s.[pos] … s.[pos+len-1]] by [by] in [s] *)
 let replace_at_ ~pos ~len ~by s =
   let b = Buffer.create (length s + length by - len) in
@@ -335,16 +275,6 @@ let replace ?(which=`All) ~sub ~by s =
       done;
       Buffer.contents b
 
-(*$= & ~printer:CCFun.id
-  (replace ~which:`All ~sub:"a" ~by:"b" "abcdabcd") "bbcdbbcd"
-  (replace ~which:`Left ~sub:"a" ~by:"b" "abcdabcd") "bbcdabcd"
-  (replace ~which:`Right ~sub:"a" ~by:"b" "abcdabcd") "abcdbbcd"
-  (replace ~which:`All ~sub:"ab" ~by:"hello" "  abab cdabb a") \
-    "  hellohello cdhellob a"
-  (replace ~which:`Left ~sub:"ab" ~by:"nope" " a b c d ") " a b c d "
-  (replace ~sub:"a" ~by:"b" "1aa234a") "1bb234b"
-*)
-
 module Split = struct
   type drop_if_empty = {
     first: bool;
@@ -403,12 +333,6 @@ module Split = struct
 
   let list_cpy ?(drop=default_drop) ~by s = _mklist ~drop ~by s String.sub
 
-  (*$T
-    Split.list_cpy ~by:"," "aa,bb,cc" = ["aa"; "bb"; "cc"]
-    Split.list_cpy ~by:"--" "a--b----c--" = ["a"; "b"; ""; "c"; ""]
-    Split.list_cpy ~by:" " "hello  world aie" = ["hello"; ""; "world"; "aie"]
-  *)
-
   let _mkseq ~drop ~by s k =
     let by = Find.compile by in
     let rec make state () = match _split ~by s state with
@@ -444,14 +368,6 @@ module Split = struct
 
   let left ~by s = try Some (left_exn ~by s) with Not_found -> None
 
-  (*$T
-    Split.left ~by:" " "ab cde f g " = Some ("ab", "cde f g ")
-    Split.left ~by:"__" "a__c__e_f" = Some ("a", "c__e_f")
-    Split.left ~by:"_" "abcde" = None
-    Split.left ~by:"bb" "abbc" = Some ("a", "c")
-    Split.left ~by:"a_" "abcde" = None
-  *)
-
   let right_exn ~by s =
     let i = rfind ~sub:by s in
     if i = ~-1 then raise Not_found
@@ -460,13 +376,6 @@ module Split = struct
       String.sub s 0 i, String.sub s right (String.length s - right)
 
   let right ~by s = try Some (right_exn ~by s) with Not_found -> None
-
-  (*$T
-    Split.right ~by:" " "ab cde f g" = Some ("ab cde f", "g")
-    Split.right ~by:"__" "a__c__e_f" = Some ("a__c", "e_f")
-    Split.right ~by:"_" "abcde" = None
-    Split.right ~by:"a_" "abcde" = None
-  *)
 end
 
 [@@@ifge 4.04]
@@ -477,17 +386,6 @@ let split_on_char c s: _ list =
 
 [@@@endif]
 
-(*$= & ~printer:Q.Print.(list string)
-  ["a"; "few"; "words"; "from"; "our"; "sponsors"] \
-    (split_on_char ' ' "a few words from our sponsors")
-*)
-
-(*$Q
-  Q.(printable_string) (fun s -> \
-    let s = split_on_char ' ' s |> String.concat " " in \
-    s = (split_on_char ' ' s |> String.concat " "))
-*)
-
 let split ~by s = Split.list_cpy ~by s
 
 let compare_versions a b =
@@ -509,20 +407,6 @@ let compare_versions a b =
   in
   cmp_rec (Split.gen_cpy ~by:"." a) (Split.gen_cpy ~by:"." b)
 
-(*$T
-  compare_versions "0.1.3" "0.1" > 0
-  compare_versions "10.1" "2.0" > 0
-  compare_versions "0.1.alpha" "0.1" > 0
-  compare_versions "0.3.dev" "0.4" < 0
-  compare_versions "0.foo" "0.0" < 0
-  compare_versions "1.2.3.4" "01.2.4.3" < 0
-*)
-
-(*$Q
-  Q.(pair printable_string printable_string) (fun (a,b) -> \
-    CCOrd.equiv (compare_versions a b) (CCOrd.opp compare_versions b a))
-*)
-
 type nat_chunk =
   | NC_char of char
   | NC_int of int
@@ -561,25 +445,6 @@ let compare_natural a b =
   in
   cmp_rec (chunks a) (chunks b)
 
-(*$T
-  compare_natural "foo1" "foo2" < 0
-  compare_natural "foo11" "foo2" > 0
-  compare_natural "foo11" "foo11" = 0
-  compare_natural "foo011" "foo11" = 0
-  compare_natural "foo1a" "foo1b" < 0
-  compare_natural "foo1a1" "foo1a2" < 0
-  compare_natural "foo1a17" "foo1a2" > 0
-*)
-
-(*Q
-  (Q.pair printable_string printable_string) (fun (a,b) -> \
-    CCOrd.opp (compare_natural a b) = compare_natural b a)
-  (Q.printable_string) (fun a -> compare_natural a a = 0)
-  (Q.triple printable_string printable_string printable_string) (fun (a,b,c) -> \
-    if compare_natural a b < 0 && compare_natural b c < 0 \
-    then compare_natural a c < 0 else Q.assume_fail())
-*)
-
 let edit_distance ?(cutoff=max_int) s1 s2 =
   let n1 = length s1 in
   let n2 = length s2 in
@@ -622,52 +487,6 @@ let edit_distance ?(cutoff=max_int) s1 s2 =
     v1.(length s2)
   with Exit -> cutoff
 
-(*$Q
-  Q.(string_of_size Gen.(0 -- 30)) (fun s -> \
-    edit_distance s s = 0)
-  Q.(let p = string_of_size Gen.(0 -- 20) in pair p p) (fun (s1,s2) -> \
-    edit_distance s1 s2 = edit_distance s2 s1)
-  Q.(let p = string_of_size Gen.(0 -- 20) in pair p p) (fun (s1,s2) -> \
-    let e = edit_distance s1 s2 in \
-    let e' = edit_distance ~cutoff:3 s1 s2 in \
-    (if e' < 3 then e=e' else e >= 3) && \
-    (if e <= 3 then e=e' else true))
-*)
-
-(*$= & ~printer:string_of_int
-  2 (edit_distance "hello" "helo!")
-  5 (edit_distance "abcde" "tuvwx")
-  2 (edit_distance ~cutoff:2 "abcde" "tuvwx")
-  1 (edit_distance ("a" ^ String.make 100 '_') ("b"^String.make 100 '_'))
-  1 (edit_distance ~cutoff:4 ("a" ^ String.make 1000 '_') ("b"^String.make 1000 '_'))
-  2 (edit_distance ~cutoff:3 ("a" ^ String.make 1000 '_' ^ "c")\
-       ("b" ^ String.make 1000 '_' ^ "d"))
-*)
-
-(* test that building a from s, and mutating one char of s, yields
-   a string s' that is accepted by a.
-
-   --> generate triples (s, i, c) where c is a char, s a non empty string
-   and i a valid index in s.
-*)
-
-(*$QR
-  (
-    let gen = Q.Gen.(
-      3 -- 10 >>= fun len ->
-      0 -- (len-1) >>= fun i ->
-      string_size (return len) >>= fun s ->
-      char >|= fun c -> (s,i,c)
-    ) in
-    let small (s,_,_) = String.length s in
-    Q.make ~small gen
-  )
-  (fun (s,i,c) ->
-    let s' = Bytes.of_string s in
-    Bytes.set s' i c;
-    edit_distance s (Bytes.to_string s') <= 1)
-*)
-
 let repeat s n =
   assert (n>=0);
   let len = String.length s in
@@ -686,16 +505,6 @@ let prefix ~pre s =
     check 0
   )
 
-(*$T
-  prefix ~pre:"aab" "aabcd"
-  not (prefix ~pre:"ab" "aabcd")
-  not (prefix ~pre:"abcd" "abc")
-  prefix ~pre:"abc" "abcde"
-  prefix ~pre:"" ""
-  prefix ~pre:"" "abc"
-  prefix ~pre:"abc" "abc"
-*)
-
 let suffix ~suf s =
   let len = String.length suf in
   if len > String.length s then false
@@ -709,14 +518,6 @@ let suffix ~suf s =
     check 0
   )
 
-(*$T
-  suffix ~suf:"cd" "abcd"
-  suffix ~suf:"" ""
-  suffix ~suf:"" "abc"
-  not (suffix ~suf:"cd" "abcde")
-  not (suffix ~suf:"abcd" "cd")
-*)
-
 let take n s =
   if n < String.length s
   then String.sub s 0 n
@@ -729,34 +530,16 @@ let drop n s =
 
 let take_drop n s = take n s, drop n s
 
-(*$=
-  ("ab", "cd") (take_drop 2 "abcd")
-  ("abc", "") (take_drop 3 "abc")
-  ("abc", "") (take_drop 5 "abc")
-*)
-
 let chop_suffix ~suf s =
   if suffix ~suf s
   then Some (String.sub s 0 (String.length s-String.length suf))
   else None
 
-(*$= & ~printer:Q.Print.(option string)
-  (Some "ab") (chop_suffix ~suf:"cd" "abcd")
-  None (chop_suffix ~suf:"cd" "abcde")
-  None (chop_suffix ~suf:"abcd" "cd")
-*)
-
 let chop_prefix ~pre s =
   if prefix ~pre s
   then Some (String.sub s (String.length pre) (String.length s-String.length pre))
   else None
 
-(*$= & ~printer:Q.Print.(option string)
-  (Some "cd") (chop_prefix ~pre:"aab" "aabcd")
-  None (chop_prefix ~pre:"ab" "aabcd")
-  None (chop_prefix ~pre:"abcd" "abc")
-*)
-
 let blit = String.blit
 
 let fold f acc s =
@@ -780,15 +563,6 @@ let pad ?(side=`Left) ?(c=' ') n s =
       | `Left -> init n (fun i -> if i < pad_len then c else s.[i-pad_len])
       | `Right -> init n (fun i -> if i < len_s then s.[i] else c)
 
-(*$= & ~printer:Q.Print.string
-  "  42" (pad 4 "42")
-  "0042" (pad ~c:'0' 4 "42")
-  "4200" (pad ~side:`Right ~c:'0' 4 "42")
-  "hello" (pad 4 "hello")
-  "aaa" (pad ~c:'a' 3 "")
-  "aaa" (pad ~side:`Right ~c:'a' 3 "")
-*)
-
 let _to_gen s i0 len =
   let i = ref i0 in
   fun () ->
@@ -835,11 +609,6 @@ let of_list l =
   List.iter (Buffer.add_char buf) l;
   Buffer.contents buf
 
-(*$T
-  of_list ['a'; 'b'; 'c'] = "abc"
-  of_list [] = ""
-*)
-
 let of_array a =
   init (Array.length a) (fun i -> a.(i))
 
@@ -854,21 +623,6 @@ let lines_seq s = Split.seq_cpy ~drop:{Split.first=false; last=true} ~by:"\n" s
 
 let lines s = Split.list_cpy ~drop:{Split.first=false; last=true} ~by:"\n" s
 
-(*$= & ~printer:Q.Print.(list @@ Printf.sprintf "%S")
-  ["ab"; "c"] (lines "ab\nc")
-  ["ab"; "c"] (lines "ab\nc\n")
-  [] (lines "")
-  [""] (lines "\n")
-  [""; "a"] (lines "\na")
-*)
-
-(*$Q
-  Q.(printable_string) (fun s -> \
-    lines s = (lines_gen s |> Gen.to_list))
-  Q.(printable_string) (fun s -> \
-    lines s = (lines_iter s |> Iter.to_list))
-*)
-
 let concat_gen_buf ~sep g : Buffer.t =
   let b = Buffer.create 256 in
   let rec aux ~first () = match g () with
@@ -909,15 +663,6 @@ let concat_seq ~sep seq =
   let buf = concat_seq_buf ~sep seq in
   Buffer.contents buf
 
-(*$Q
-  Q.(small_list printable_string) (fun l -> \
-    concat_iter ~sep:"\n" (Iter.of_list l) = concat "\n" l)
-  Q.(small_list printable_string) (fun l -> \
-    concat_gen ~sep:"\n" (Gen.of_list l) = concat "\n" l)
-  Q.(small_list printable_string) (fun l -> \
-    concat_seq ~sep:"\n" (CCSeq.of_list l) = concat "\n" l)
-*)
-
 let unlines l =
   let len = List.fold_left (fun n s -> n + 1 + String.length s) 0 l in
   let buf = Bytes.create len in
@@ -948,32 +693,10 @@ let unlines_seq seq =
   Buffer.add_char buf '\n';
   Buffer.contents buf
 
-(*$= & ~printer:CCFun.id
-  "" (unlines [])
-  "ab\nc\n" (unlines ["ab"; "c"])
-*)
-
-(*$Q
-  Q.printable_string (fun s -> trim (unlines (lines s)) = trim s)
-  Q.printable_string (fun s -> trim (unlines_gen (lines_gen s)) = trim s)
-*)
-
-(*$Q
-  Q.(small_list small_string) (fun l -> \
-    let l = unlines l |> lines in \
-    l = (unlines l |> lines))
-*)
-
 let set s i c =
   if i<0 || i>= String.length s then invalid_arg "CCString.set";
   init (String.length s) (fun j -> if i=j then c else s.[j])
 
-(*$T
-  set "abcd" 1 '_' = "a_cd"
-  set "abcd" 0 '-' = "-bcd"
-  (try ignore (set "abc" 5 '_'); false with Invalid_argument _ -> true)
-*)
-
 let iter = String.iter
 
 let filter_map f s =
@@ -985,11 +708,6 @@ let filter_map f s =
     s;
   Buffer.contents buf
 
-(*$= & ~printer:Q.Print.string
-  "bcef" (filter_map \
-     (function 'c' -> None | c -> Some (Char.chr (Char.code c + 1))) "abcde")
-*)
-
 let filter f s =
   let buf = Buffer.create (String.length s) in
   iter
@@ -997,14 +715,6 @@ let filter f s =
     s;
   Buffer.contents buf
 
-(*$= & ~printer:Q.Print.string
-  "abde" (filter (function 'c' -> false | _ -> true) "abcdec")
-*)
-
-(*$Q
-  Q.printable_string (fun s -> filter (fun _ -> true) s = s)
-*)
-
 let uniq eq s =
   if String.length s = 0 then s
   else begin
@@ -1019,10 +729,6 @@ let uniq eq s =
     Buffer.contents buf
   end
 
-(*$= & ~printer:Q.Print.string
-  "abcde" (uniq CCShims_.Stdlib.(=) "abbccdeeeee")
-*)
-
 let flat_map ?sep f s =
   let buf = Buffer.create (String.length s) in
   iteri
@@ -1064,24 +770,6 @@ let is_space_ = function
 let ltrim s = drop_while is_space_ s
 let rtrim s = rdrop_while is_space_ s
 
-(*$= & ~printer:id
-  "abc " (ltrim " abc ")
-  " abc" (rtrim " abc ")
-*)
-
-(*$Q
-  Q.(printable_string) (fun s -> \
-    String.trim s = (s |> ltrim |> rtrim))
-  Q.(printable_string) (fun s -> ltrim s = ltrim (ltrim s))
-  Q.(printable_string) (fun s -> rtrim s = rtrim (rtrim s))
-  Q.(printable_string) (fun s -> \
-    let s' = ltrim s in \
-    if s'="" then Q.assume_fail() else s'.[0] <> ' ')
-  Q.(printable_string) (fun s -> \
-    let s' = rtrim s in \
-    if s'="" then Q.assume_fail() else s'.[String.length s'-1] <> ' ')
-*)
-
 let map2 f s1 s2 =
   if length s1 <> length s2 then invalid_arg "CCString.map2";
   init (String.length s1) (fun i -> f s1.[i] s2.[i])
@@ -1122,18 +810,6 @@ let equal_caseless s1 s2: bool =
     (fun c1 c2 -> CCChar.equal (CCChar.lowercase_ascii c1) (CCChar.lowercase_ascii c2))
     s1 s2
 
-(*$T
-  equal_caseless "foo" "FoO"
-  equal_caseless "helLo" "HEllO"
-*)
-
-(*$Q
-  Q.(pair printable_string printable_string) (fun (s1,s2) -> \
-    equal_caseless s1 s2 = (lowercase_ascii s1=lowercase_ascii s2))
-  Q.(printable_string) (fun s -> equal_caseless s s)
-  Q.(printable_string) (fun s -> equal_caseless (uppercase_ascii s) s)
-*)
-
 let to_hex (s:string) : string =
   let i_to_hex (i:int) =
     if i < 10 then Char.chr (i + Char.code '0')
@@ -1167,20 +843,6 @@ let of_hex_exn (s:string) : string =
 
 let of_hex s = try Some (of_hex_exn s) with Invalid_argument _ -> None
 
-(*$= & ~printer:(Printf.sprintf "%S")
-  "0068656c6c6f20776f726c64" (to_hex "\000hello world")
-  "" (to_hex "")
-  "\000hello world" (of_hex_exn "0068656c6c6f20776f726c64")
-  "hello world" (of_hex_exn "68656C6C6F20776F726C64")
-*)
-
-(*$Q
-  Q.(string) (fun s -> \
-    of_hex_exn (to_hex s) = s)
-  Q.(string) (fun s -> \
-    CCString.for_all (function 'A'..'F'|'a'..'f'|'0'..'9' -> true |  _ -> false) @@ to_hex s)
-*)
-
 let pp_buf buf s =
   Buffer.add_char buf '"';
   Buffer.add_string buf s;
@@ -1199,8 +861,3 @@ module Infix = struct
 end
 
 include Infix
-
-(*$T
-  "ab" < "abc"
-  "123" < "14"
- *)
diff --git a/src/core/CCUtf8_string.ml b/src/core/CCUtf8_string.ml
index abc4666d..b9f3893d 100644
--- a/src/core/CCUtf8_string.ml
+++ b/src/core/CCUtf8_string.ml
@@ -141,22 +141,6 @@ let to_seq ?(idx=0) s : uchar Seq.t =
   let st = Dec.make ~idx s in
   loop st
 
-(*$= & ~cmp:(=) ~printer:Q.Print.(list (fun c -> string_of_int@@ Uchar.to_int c))
-  (to_list (of_string_exn "aébõ😀")) (to_seq (of_string_exn "aébõ😀") |> CCList.of_seq)
-  *)
-
-(* make sure it's persisted correctly *)
-(*$R
-  let s = (of_string_exn "aébõ😀") in
-  let seq = to_seq s in
-  let l = to_list s in
-  let testeq seq = assert_equal ~cmp:(=) l (CCList.of_seq seq) in
-  testeq seq;
-  testeq seq;
-  testeq seq;
-  *)
-
-
 let iter ?idx f s = to_iter ?idx s f
 
 let fold ?idx f acc s =
@@ -318,168 +302,3 @@ let of_string_exn s =
   else invalid_arg "CCUtf8_string.of_string_exn"
 
 let of_string s = if is_valid s then Some s else None
-
-(*$inject
-
-  let printer s = String.escaped (to_string s)
-  let pp_uchar (c:Uchar.t) = Printf.sprintf "0x%x" (Uchar.to_int c)
-
-  let arb_uchar =
-    let rec gen  = lazy (
-      let open Q.Gen in
-      Q.Gen.int_range Uchar.(to_int min) Uchar.(to_int max) >>= fun n ->
-      try return (Uchar.of_int n)
-      with _ -> Lazy.force gen
-    ) in
-    Q.make
-      ~print:(fun c -> Printf.sprintf "<uchar '%d'>" (Uchar.to_int c))
-      (Lazy.force gen)
-
-  let uutf_is_valid s =
-  try
-    Uutf.String.fold_utf_8
-      (fun () _ -> function
-         | `Malformed _ -> raise Exit
-         | `Uchar _ -> ())
-      () s;
-    true
-  with Exit ->
-    false
-
-  let uutf_to_iter s f =
-  Uutf.String.fold_utf_8
-    (fun () _ -> function
-       | `Malformed _ -> f (Uchar.of_int 0xfffd)
-       | `Uchar c -> f c)
-      () s
-
-  let uutf_of_l l =
-    let buf = Buffer.create 32 in
-    List.iter (Uutf.Buffer.add_utf_8 buf) l;
-    Buffer.contents buf
-*)
-
-(*$R
-  let s = of_string_exn "このため、" in
-  let s' = to_iter s |> of_iter in
-  assert_equal ~cmp:equal ~printer s s'
-*)
-
-(*$QR
-  Q.small_string (fun s ->
-    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
-    is_valid s)
-*)
-
-(*$QR & ~long_factor:10
-  Q.small_string (fun s ->
-    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
-    s = (of_string_exn s |> to_iter|> of_iter|> to_string)
-  )
-*)
-
-(*$QR & ~long_factor:10
-  Q.string (fun s ->
-    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
-    String.length s = List.length (of_string_exn s |> to_list)
-  )
-*)
-
-(*$QR & ~long_factor:10 ~count:20_000
-  Q.(small_list arb_uchar) (fun l ->
-      let s = of_list l in
-      l = to_list s)
-*)
-
-(*$QR & ~long_factor:10
-  Q.(small_list arb_uchar) (fun l ->
-      let s = of_list l in
-      l = (to_list @@ of_gen @@ to_gen s)
-  )
-*)
-
-(*$QR & ~long_factor:10
-  Q.(small_list arb_uchar) (fun l ->
-      let s = of_list l in
-      l = (to_list @@ of_iter @@ to_iter s)
-  )
-*)
-
-(*$T
-  not (is_valid "\192\181")
-  not (is_valid "\193\143")
-  not (is_valid "\224\151\167")
-  not (is_valid "\224\137\165")
-  is_valid "\240\151\189\163"
-*)
-
-(*$QR & ~long_factor:40
-  Q.string (fun s ->
-    Q.assume (is_valid s);
-    let s = of_string_exn s in
-    let s2 = s |> to_iter|> of_iter in
-    if s=s2 then true
-    else Q.Test.fail_reportf "s=%S, s2=%S" (to_string s)(to_string s2)
-  )
-*)
-
-(*$QR & ~long_factor:40
-  Q.string (fun s ->
-    Q.assume (is_valid s);
-    let s = of_string_exn s in
-    let s2 = s |> to_gen |> of_gen in
-    if s=s2 then true
-    else Q.Test.fail_reportf "s=%S, s2=%S" (to_string s)(to_string s2)
-  )
-*)
-
-(* compare with uutf *)
-
-(*$QR & ~long_factor:40 ~count:50_000
-  Q.small_string (fun s ->
-    let v1 = is_valid s in
-    let v2 = uutf_is_valid s in
-    if v1=v2 then true
-    else Q.Test.fail_reportf "s:%S, valid: %B, uutf_valid: %B" s v1 v2
-  )
-*)
-
-(*$QR & ~long_factor:40 ~count:50_000
-  Q.(small_list arb_uchar) (fun l ->
-    let pp s = Q.Print.(list pp_uchar) s in
-    let uutf = uutf_of_l l in
-    let s = (of_list l:>string) in
-    if uutf = s then true
-    else Q.Test.fail_reportf "l: '%s', uutf: '%s', containers: '%s'"
-      (pp l) uutf s
-  )
-*)
-
-(*$QR & ~long_factor:40 ~count:50_000
-  Q.small_string (fun s ->
-    Q.assume (is_valid s && uutf_is_valid s);
-    let pp s = Q.Print.(list pp_uchar) s in
-    let l_uutf = uutf_to_iter s |> Iter.to_list in
-    let l_co = of_string_exn s |> to_iter |> Iter.to_list in
-    if l_uutf = l_co then true
-    else Q.Test.fail_reportf "uutf: '%s', containers: '%s', is_valid %B, uutf_is_valid %B"
-      (pp l_uutf) (pp l_co) (is_valid s) (uutf_is_valid s)
-  )
-*)
-
-(*$R
-  for i = 0 to 127 do
-    let c = Uchar.of_int i in
-    assert_equal 1 (n_bytes (of_list [c]))
-  done
-*)
-
-(*$QR
-  Q.(small_list arb_uchar) (fun l ->
-        of_list l = concat empty (List.map of_uchar l))
-  *)
-
-(*$QR
-    Q.(pair small_nat arb_uchar) (fun (i,c) ->
-        make i c = concat empty (CCList.init i (fun _ -> of_uchar c)))
-  *)
diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 8d512537..07ccf4da 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -54,20 +54,11 @@ let create_with ?(capacity=128) x =
   vec
 }
 
-(*$T
-  (create_with ~capacity:200 1 |> capacity) >= 200
-*)
-
 let return x = {
   size=1;
   vec= [| x |];
 }
 
-(*$T
-  return 42 |> to_list = [42]
-  return 42 |> length = 1
-*)
-
 let make n x = {
   size=n;
   vec=Array.make n x;
@@ -96,33 +87,6 @@ let resize_ v newcapacity x =
   v.vec <- new_vec;
   ()
 
-(*$T
-  let v = create_with ~capacity:10 1 in \
-    ensure v 200; capacity v >= 200
-*)
-
-(*$T
-  let v = create() in push v 0.; push v 1.; push v 2.; 3=length v
-  let v = create() in push v 1.; push v 2.; push v 3.; 6. = (get v 0 +. get v 1 +. get v 2)
-  let v = create() in push v 0; push v 1; push v 2; 3=length v
-  let v = create() in push v 1; push v 2; push v 3; 6 = (get v 0 + get v 1 + get v 2)
-  let v = create() in push v "a"; push v "b"; push v "c"; 3=length v
-  let v = create() in push v "a"; push v "b"; push v "c"; "abc" = String.concat "" (to_list v)
-*)
-
-(*$R
-  let v = create() in
-  push v 0.; push v 1.;
-  clear v;
-  push v 0.; push v 1.; push v 7.; push v 10.; push v 12.;
-  truncate v 2;
-  assert_equal 1. (fold (+.) 0. v);
-  clear v;
-  assert_equal 0 (size v);
-  push v 0.; push v 1.; push v 7.; push v 10.; push v 12.;
-  assert_equal (1. +. 7. +. 10. +. 12.) (fold (+.) 0. v);
-  *)
-
 (* grow the array, using [x] as a filler if required *)
 let grow_with_ v ~filler:x =
   if array_is_empty_ v then (
@@ -168,14 +132,6 @@ let ensure v size =
 let[@inline] clear v =
   v.size <- 0
 
-(*$R
-  let v = of_iter Iter.(1 -- 10) in
-  OUnit2.assert_equal 10 (size v);
-  clear v;
-  OUnit2.assert_equal 0 (size v);
-  OUnit2.assert_bool "empty_after_clear" (Iter.is_empty (to_iter v));
-*)
-
 let clear_and_reset v =
   v.size <- 0;
   v.vec <- [||]
@@ -202,11 +158,6 @@ let push v x =
   if v.size = Array.length v.vec then grow_with_ v ~filler:x;
   push_unsafe_ v x
 
-(*$T
-  let v = create () in push v 1; to_list v = [1]
-  let v = of_list [1;2;3] in push v 4; to_list v = [1;2;3;4]
-*)
-
 let resize_with v f size =
   if size<0 then invalid_arg "Vec.resize_with";
   if Array.length v.vec = 0 then (
@@ -221,17 +172,6 @@ let resize_with v f size =
     v.size <- size
   )
 
-(*$T
-  let v = make 1 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4]
-  let v = make 1 0 in resize_with v (fun i -> i) 5; CCList.length (to_list v) = 5
-  let v = create_with ~capacity:2 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4]
-  let v = make 5 0 in resize_with v (fun i -> i) 5; to_list v = [0;0;0;0;0]
-  let v = make 5 0 in resize_with v (fun i -> i) 6; to_list v = [0;0;0;0;0;5]
-  let v = make 5 0 in try resize_with v (fun i -> i) (-1); false \
-    with Invalid_argument _ -> true
-  let v = make 5 0 in resize_with v (fun i -> i) 5; List.length (to_list v) = 5
-*)
-
 let resize_with_init v ~init size =
   if size<0 then invalid_arg "Vec.resize_with_init";
   if Array.length v.vec = 0 then (
@@ -246,23 +186,6 @@ let resize_with_init v ~init size =
     v.size <- size;
   )
 
-(*$T
-  let v = make 1 0 in resize_with_init v ~init:1 5; to_list v = [0;1;1;1;1]
-  let v = make 1 0 in resize_with_init v ~init:1 5; List.length (to_list v) = 5
-
-  let v = create_with ~capacity:2 0 in resize_with_init v ~init:1 5; to_list v = [1;1;1;1;1]
-  let v = make 5 0 in resize_with_init v ~init:1 5; to_list v = [0;0;0;0;0]
-  let v = make 3 0 in resize_with_init v ~init:1 5; to_list v = [0;0;0;1;1]
-  let v = make 5 0 in try resize_with_init v  ~init:1 (-1); false \
-    with Invalid_argument _ -> true
-  let v = make 5 0 in resize_with_init v ~init:1 5; List.length (to_list v) = 5
-*)
-
-(* test for asymptotic behavior *)
-(*$T
-  let v =make 1 0 in for i=0 to 100_000 do resize_with_init v ~init:10 i; done; true
-  *)
-
 (** Add all elements of b to a *)
 let append a b =
   if array_is_empty_ a then (
@@ -278,28 +201,6 @@ let append a b =
     a.size <- a.size + b.size
   )
 
-(*$T
-  let v1 = init 5 (fun i->i) and v2 = init 5 (fun i->i+5) in \
-  append v1 v2; to_list v1 = CCList.(0--9)
-  let empty = create () and v2 = init 5 (fun i->i) in \
-  append empty v2; to_list empty = CCList.(0--4)
-  let v1 = init 5 (fun i->i) and empty = create () in \
-  append v1 empty; to_list v1 = CCList.(0--4)
-  let v = init 3 (fun i->i) in \
-  append v v; to_list v = [0; 1; 2; 0; 1; 2]
-  let empty = create () in \
-  append empty empty; to_list empty = []
-*)
-
-(*$R
-  let a = of_iter Iter.(1 -- 5) in
-  let b = of_iter Iter.(6 -- 10) in
-  append a b;
-  OUnit2.assert_equal 10 (size a);
-  OUnit2.assert_equal (Iter.to_array Iter.(1 -- 10)) (to_array a);
-  OUnit2.assert_equal (Iter.to_array Iter.(6 -- 10)) (to_array b);
-*)
-
 let[@inline] get v i =
   if i < 0 || i >= v.size then invalid_arg "CCVector.get";
   Array.unsafe_get v.vec i
@@ -326,25 +227,6 @@ let remove_unordered v i =
   v.size <- v.size - 1;
   fill_with_junk_ v.vec v.size 1
 
-(*$Q remove_and_shift
-  Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l -> \
-    let v1 = of_list l and v2 = of_list l in \
-    remove_and_shift v1 9; \
-    remove_unordered v2 9; \
-    to_list v1 = (to_list v2))
-  Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l -> \
-    let l = List.sort CCInt.compare l in \
-    let v = of_list l in\
-    remove_and_shift v 3; \
-    to_list v = (List.sort CCInt.compare (to_list v)))
-  Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l -> \
-    let l = List.sort CCInt.compare l in \
-    let v1 = of_list l and v2 = of_list l in \
-    remove_and_shift v1 3; \
-    remove_unordered v2 3; \
-    to_list v1 = (List.sort CCInt.compare (to_list v2)))
-*)
-
 let insert v i x =
   (* Note that we can insert at i=v.size *)
   if i < 0 || i > v.size then invalid_arg "CCVector.insert";
@@ -355,14 +237,6 @@ let insert v i x =
   v.vec.(i) <- x;
   v.size <- v.size + 1
 
-(*$T
-  let v = (1 -- 5) in insert v 3 9; to_list v = [1;2;3;9;4;5]
-  let v = create () in insert v 0 2; to_list v = [2]
-  let v = (1 -- 3) in remove_and_shift v 1; insert v 1 5; to_list v = [1;5;3]
-  let v = (1 -- 3) in remove_and_shift v 0; insert v 2 5; to_list v = [2;3;5]
-  let v = (1 -- 3) in insert v 3 5; to_list v = [1;2;3;5]
-*)
-
 let[@inline] append_iter a i = i (fun x -> push a x)
 
 let append_seq a seq = Seq.iter (fun x -> push a x) seq
@@ -378,17 +252,6 @@ let append_array a b =
     a.size <- a.size + len_b
   )
 
-(*$T
-  let v1 = init 5 (fun i->i) and v2 = Array.init 5 (fun i->i+5) in \
-  append_array v1 v2; to_list v1 = CCList.(0--9)
-  let empty = create () in \
-  append_array empty CCArray.(0--5); to_list empty = CCList.(0--5)
-  let v1 = init 5 (fun i->i) in \
-  append_array v1 [| |]; to_list v1 = CCList.(0--4)
-  let empty = create () in \
-  append_array empty [| |]; to_list empty = []
-*)
-
 let append_list a b = match b with
   | [] -> ()
   | x :: _ ->
@@ -399,45 +262,10 @@ let append_list a b = match b with
     List.iter (push_unsafe_ a) b;
     ()
 
-(*$Q
-  Q.(pair (list int)(list int)) (fun (l1,l2) -> \
-    let v = of_list l1 in append_list v l2; \
-    to_list v = (l1 @ l2))
-  Q.(pair (list int)(list int)) (fun (l1,l2) -> \
-    let v = of_list l1 in append_list v l2; \
-    length v = List.length l1 + List.length l2)
-*)
-
 let rec append_gen a b = match b() with
   | None -> ()
   | Some x -> push a x; append_gen a b
 
-(*$Q
-  Q.(pair (list int)(list int)) (fun (l1,l2) -> \
-    let v = of_list l1 in append_gen v (Gen.of_list l2); \
-    to_list v = (l1 @ l2))
-  Q.(pair (list int)(list int)) (fun (l1,l2) -> \
-    let v = of_list l1 in append_gen v (Gen.of_list l2); \
-    length v = List.length l1 + List.length l2)
-*)
-
-
-(*$inject
-  let gen x =
-    let small = length in
-    let print = CCOption.map (fun p x -> Q.Print.list p (CCVector.to_list x)) x.Q.print in
-    Q.make ?print ~small Q.Gen.(list x.Q.gen >|= of_list)
-*)
-
-(*$QR
-  (Q.pair (gen Q.int) (gen Q.int)) (fun (v1,v2) ->
-    let l1 = to_list v1 in
-    append v1 v2;
-    Iter.to_list (to_iter v1) =
-      Iter.(to_list (append (of_list l1) (to_iter v2)))
-  )
-*)
-
 let equal eq v1 v2 =
   v1.size = v2.size
   &&
@@ -447,25 +275,6 @@ let equal eq v1 v2 =
   in
   check 0
 
-(*$T
-  equal (=) (create ()) (create ())
-  equal (=) (return 42) (return 42)
-  not (equal (=) (create ()) (return 42))
-  not (equal (=) (return 42) (create ()))
-*)
-
-(*$Q
-  Q.(let g = list_of_size Gen.(0--10) small_int in pair g g) (fun (l1,l2) -> \
-    equal (=) (of_list l1) (of_list l2) = (l1=l2))
-*)
-
-(*$QR
-  Q.(pair (small_list small_int)(small_list small_int)) (fun (l1,l2) ->
-    let v1 = of_list l1 in
-    let v2 = of_list l2 in
-    equal (=) v1 v2 = (l1=l2))
-*)
-
 let compare cmp v1 v2 =
   let n = min v1.size v2.size in
   let rec check i =
@@ -477,13 +286,6 @@ let compare cmp v1 v2 =
     )
   in check 0
 
-(*$QR
-  Q.(pair (small_list small_int)(small_list small_int)) (fun (l1,l2) ->
-    let v1 = of_list l1 in
-    let v2 = of_list l2 in
-    compare Stdlib.compare v1 v2 = CCList.compare Stdlib.compare l1 l2)
-*)
-
 exception Empty
 
 let pop_exn v =
@@ -506,40 +308,11 @@ let[@inline] top_exn v =
   if v.size = 0 then raise Empty;
   Array.unsafe_get v.vec (v.size-1)
 
-(*$T
-  1 -- 10 |> top = Some 10
-  create () |> top = None
-  1 -- 10 |> top_exn = 10
-*)
-
 let[@inline] copy v = {
   size = v.size;
   vec = Array.sub v.vec 0 v.size;
 }
 
-(*$T
-  (let v = of_list [1;2;3] in let v' = copy v in \
-    to_list v' = [1;2;3])
-  create () |> copy |> is_empty
-*)
-
-(*$R
-  let v = of_iter Iter.(1 -- 100) in
-  OUnit2.assert_equal 100 (size v);
-  let v' = copy v in
-  OUnit2.assert_equal 100 (size v');
-  clear v';
-  OUnit2.assert_bool "empty" (is_empty v');
-  OUnit2.assert_bool "not_empty" (not (is_empty v));
-*)
-
-(*$QR
-  Q.(small_list small_int) (fun l ->
-    let v = of_list l in
-    let v' = copy v in
-    equal (=) v v')
-*)
-
 let truncate v n =
   let old_size = v.size in
   if n < old_size then (
@@ -548,23 +321,6 @@ let truncate v n =
     fill_with_junk_ v.vec n (old_size-n);
   )
 
-(*$R
-  let v = of_iter Iter.(1 -- 10) in
-  truncate v 5;
-  OUnit2.assert_equal [1;2;3;4;5] (to_list v);
-*)
-
-(*$QR
-  (gen Q.small_int) (fun v ->
-    let n = size v / 2 in
-    let l = to_list v in
-    let h = Iter.(to_list (take n (of_list l))) in
-    let v' = copy v in
-    truncate v' n;
-    h = to_list v'
-  )
-*)
-
 let shrink_to_fit v : unit =
   if v.size = 0 then (
     v.vec <- [| |]
@@ -572,14 +328,6 @@ let shrink_to_fit v : unit =
     v.vec <- Array.sub v.vec 0 v.size
   )
 
-(*$QR
-  (gen Q.small_int) (fun v ->
-    let v' = copy v in
-    shrink_to_fit v;
-    to_list v = to_list v'
-  )
-*)
-
 let sort' cmp v =
   (* possibly copy array (to avoid junk at its end), then sort the array *)
   let a =
@@ -597,15 +345,6 @@ let sort cmp v =
   Array.sort cmp v'.vec;
   v'
 
-(*$QR
-  (gen Q.small_int) (fun v ->
-    let v' = copy v in
-    sort' Stdlib.compare v';
-    let l = to_list v' in
-    List.sort Stdlib.compare l = l
-  )
-*)
-
 let uniq_sort cmp v =
   sort' cmp v;
   let n = v.size in
@@ -628,18 +367,6 @@ let uniq_sort cmp v =
   then traverse v.vec.(0) 1 1
 (* start at 1, to get the first element in hand *)
 
-(*$T
-  let v = of_list [1;4;5;3;2;4;1] in \
-  uniq_sort Stdlib.compare v; to_list v = [1;2;3;4;5]
-*)
-
-(*$QR & ~long_factor:10
-  Q.(small_list small_int) (fun l ->
-    let v = of_list l in
-    uniq_sort Stdlib.compare v;
-    to_list v = (CCList.sort_uniq ~cmp:Stdlib.compare l))
-*)
-
 let iter k v =
   let n = v.size in
   for i = 0 to n-1 do
@@ -652,11 +379,6 @@ let iteri k v =
     k i (Array.unsafe_get v.vec i)
   done
 
-(*$T
-  let v = (0--6) in \
-    iteri (fun i x ->  if i = 3 then remove_unordered v i) v; length v = 6
-*)
-
 let map f v =
   if array_is_empty_ v
   then create ()
@@ -665,17 +387,6 @@ let map f v =
     { size=v.size; vec; }
   )
 
-(*$T
-  let v = create() in push v 1; push v 2; push v 3; \
-  to_list (map string_of_int v) = ["1"; "2"; "3"]
-*)
-
-(*$QR
-  Q.(pair (fun1 Observable.int small_int) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    to_list (map f v) = List.map f l)
-*)
-
 let mapi f v =
   if array_is_empty_ v
   then create ()
@@ -684,30 +395,11 @@ let mapi f v =
     { size=v.size; vec; }
   )
 
-(*$T mapi
-  let v = create() in push v 1; push v 2; push v 3; \
-  to_list (mapi (fun i e -> Printf.sprintf "%i %i" i e) v) = ["0 1"; "1 2"; "2 3"]
-*)
-
-(*$QR mapi
-  Q.(pair (fun2 Observable.int Observable.int small_int) (small_list small_int))
-    (fun (Q.Fun (_,f),l) ->
-      let v = of_list l in
-      to_list (mapi f v) = List.mapi f l)
-*)
-
 let map_in_place f v =
   iteri
     (fun i x -> Array.unsafe_set v.vec i (f x))
     v
 
-(*$QR
-  Q.(pair (fun1 Observable.int small_int) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    map_in_place f v;
-    to_list v = List.map f l)
-*)
-
 
 let filter_in_place p v =
   let i = ref 0 in (* cur element *)
@@ -726,18 +418,6 @@ let filter_in_place p v =
   fill_with_junk_ v.vec !j (v.size - !j);
   v.size <- !j
 
-(*$T
-  let v = 1 -- 10 in filter_in_place (fun x->x<4) v; \
-    to_list v = [1;2;3]
-*)
-
-(*$QR
-  Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    filter_in_place f v;
-    to_list v = List.filter f l)
-*)
-
 let filter p v =
   if array_is_empty_ v then (
     create ()
@@ -749,17 +429,6 @@ let filter p v =
     v'
   )
 
-(*$T
-  filter (fun x-> x mod 2=0) (of_list [1;2;3;4;5]) |> to_list = [2;4]
-  filter (fun x-> x mod 2=0) (1 -- 1_000_000) |> length = 500_000
-*)
-
-(*$QR
-  Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    to_list (filter f v) = List.filter f l)
-*)
-
 let fold f acc v =
   let rec fold acc i =
     if i = v.size then acc
@@ -768,17 +437,6 @@ let fold f acc v =
       fold (f acc x) (i+1)
   in fold acc 0
 
-(*$T
-  fold (+) 0 (of_list [1;2;3;4;5]) = 15
-  fold (+) 0 (create ()) = 0
-*)
-
-(*$QR
-  Q.(pair (fun2 Observable.int Observable.int small_int) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    fold f 0 v = List.fold_left f 0 l)
-*)
-
 let exists p v =
   let n = v.size in
   let rec check i =
@@ -786,12 +444,6 @@ let exists p v =
     else p v.vec.(i) || check (i+1)
   in check 0
 
-(*$QR
-  Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    exists f v = List.exists f l)
-*)
-
 let for_all p v =
   let n = v.size in
   let rec check i =
@@ -799,12 +451,6 @@ let for_all p v =
     else p v.vec.(i) && check (i+1)
   in check 0
 
-(*$QR
-  Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    for_all f v = List.for_all f l)
-*)
-
 let member ~eq x v =
   exists (eq x) v
 
@@ -828,12 +474,6 @@ let find p v =
   try Some (find_internal_ p v)
   with Not_found -> None
 
-(*$QR
-  Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    find f v = CCList.find_pred f l)
-*)
-
 let find_map f v =
   let n = v.size in
   let rec search i =
@@ -844,13 +484,6 @@ let find_map f v =
   in
   search 0
 
-(*$Q
-  Q.(list small_int) (fun l -> \
-    let v = of_list l in \
-    let f x = x>30 && x < 35 in \
-    find_map (fun x -> if f x then Some x else None) v = find f v)
-*)
-
 let filter_map f v =
   let v' = create () in
   iter
@@ -860,12 +493,6 @@ let filter_map f v =
     v;
   v'
 
-(*$QR
-  Q.(pair (fun1 Observable.int (option bool)) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    to_list (filter_map f v) = CCList.filter_map f l)
-*)
-
 let filter_map_in_place f v =
   let i = ref 0 in (* cur element *)
   let j = ref 0 in  (* cur insertion point *)
@@ -884,26 +511,6 @@ let filter_map_in_place f v =
   fill_with_junk_ v.vec !j (v.size - !j);
   v.size <- !j
 
-(*$QR
-  Q.(pair (fun1 Observable.int (option small_int)) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
-    let v = of_list l in
-    filter_map_in_place f v;
-    to_list v = CCList.filter_map f l)
-*)
-
-(* check it frees memory properly *)
-(*$R
-  let s = "coucou" ^ "lol" in
-  let w = Weak.create 1 in
-  Weak.set w 0 (Some s);
-  let v = of_list ["a"; s] in
-  filter_in_place (fun s -> String.length s <= 1) v;
-  assert_equal 1 (length v);
-  assert_equal "a" (get v 0);
-  Gc.full_major();
-  assert_equal None (Weak.get w 0);
-*)
-
 let flat_map f v =
   let v' = create () in
   iter (fun x -> iter (push v') (f x)) v;
@@ -944,13 +551,6 @@ let monoid_product f a1 a2 : _ t =
        let j = i_prod / na1 in
        f a1.vec.(i) a2.vec.(j))
 
-(*$= & ~cmp:(=) ~printer:Q.Print.(list int)
-  [ 11; 12; 21; 22 ] (List.sort CCInt.compare @@ \
-                      to_list @@ monoid_product (+) (of_list [10; 20]) (of_list [1; 2]))
-  [ 11; 12; 13; 14 ] (List.sort CCInt.compare @@ \
-                      to_list @@ monoid_product (+) (of_list [10]) (of_list [1; 2; 3; 4]))
-*)
-
 let (>>=) x f = flat_map f x
 
 let (>|=) x f = map f x
@@ -968,46 +568,17 @@ let rev_in_place v =
     done
   )
 
-(*$QR
-  Q.(small_list small_int) (fun l ->
-    let v = of_list l in
-    rev_in_place v;
-    to_list v = List.rev l)
-*)
-
 let rev v =
   let v' = copy v in
   rev_in_place v';
   v'
 
-(*$T
-  rev (of_list [1;2;3;4]) |> to_list = [4;3;2;1]
-  rev (of_list [1;2;3;4;5]) |> to_list = [5;4;3;2;1]
-  rev (create ()) |> to_list = []
-*)
-
-(*$QR
-  Q.(small_list small_int) (fun l ->
-    let v = of_list l in
-    to_list (rev v) = List.rev l)
-*)
-
 let rev_iter f v =
   let n = v.size in
   for i = n-1 downto 0 do
     f (Array.unsafe_get v.vec i)
   done
 
-(*$T
-  let v = of_list [1;2;3] in (fun f->rev_iter f v) |> Iter.to_list = [3;2;1]
-*)
-
-(*$Q
-  Q.(list int) (fun l -> \
-    let v = of_list l in \
-    (fun f->rev_iter f v) |> Iter.to_list = List.rev l)
-*)
-
 let size v = v.size
 
 let length v = v.size
@@ -1024,10 +595,6 @@ let of_seq ?(init=create ()) seq =
   append_seq init seq;
   init
 
-(*$T
-  of_iter Iter.(1 -- 10) |> to_list = CCList.(1 -- 10)
-*)
-
 let to_iter v k = iter k v
 
 let to_iter_rev v k =
@@ -1050,11 +617,6 @@ let to_seq_rev v =
   in
   aux (size v-1)
 
-(*$Q
-  Q.(list int) (fun l -> \
-    let v= of_list l in v |> to_iter_rev |> Iter.to_rev_list = l)
-*)
-
 let slice_iter v start len =
   assert (start >= 0 && len >= 0);
   fun k ->
@@ -1064,12 +626,6 @@ let slice_iter v start len =
       k x
     done
 
-(*$T
-  slice_iter (of_list [0;1;2;3;4]) 1 3 |> CCList.of_iter = [1;2;3]
-  slice_iter (of_list [0;1;2;3;4]) 1 4 |> CCList.of_iter = [1;2;3;4]
-  slice_iter (of_list [0;1;2;3;4]) 0 5 |> CCList.of_iter = [0;1;2;3;4]
-*)
-
 let slice v = (v.vec, 0, v.size)
 
 let (--) i j =
@@ -1077,28 +633,12 @@ let (--) i j =
   then init (i-j+1) (fun k -> i-k)
   else init (j-i+1) (fun k -> i+k)
 
-(*$T
-  (1 -- 4) |> to_list = [1;2;3;4]
-  (4 -- 1) |> to_list = [4;3;2;1]
-  (0 -- 0) |> to_list = [0]
-*)
-
-(*$Q
-  Q.(pair small_int small_int) (fun (a,b) -> \
-    (a -- b) |> to_list = CCList.(a -- b))
-*)
-
 let (--^) i j =
   if i=j then create()
   else if i>j
   then init (i-j) (fun k -> i-k)
   else init (j-i) (fun k -> i+k)
 
-(*$Q
-  Q.(pair small_int small_int) (fun (a,b) -> \
-    (a --^ b) |> to_list = CCList.(a --^ b))
-*)
-
 let of_array a =
   if Array.length a = 0
   then create ()
@@ -1116,10 +656,6 @@ let of_list l = match l with
     List.iter (push_unsafe_ v) l;
     v
 
-(*$T
-  of_list CCList.(1--300_000) |> to_list = CCList.(1--300_000)
-*)
-
 let to_array v =
   Array.sub v.vec 0 v.size
 
@@ -1142,10 +678,6 @@ let to_gen v =
       Some x
     ) else None
 
-(*$T
-  let v = (1--10) in to_list v = Gen.to_list (to_gen v)
-*)
-
 let to_string ?(start="") ?(stop="") ?(sep=", ") item_to_string v =
   start ^ (to_list v |> List.map item_to_string |> String.concat sep) ^ stop
 
diff --git a/src/testlib/containers_testlib.ml b/src/testlib/containers_testlib.ml
index e9c9df7c..aa0a7d83 100644
--- a/src/testlib/containers_testlib.ml
+++ b/src/testlib/containers_testlib.ml
@@ -18,6 +18,7 @@ module Test = struct
       count: int option;
       arb: 'a Q.arbitrary;
       prop: 'a -> bool;
+      long_factor: int option;
     } -> run
 
   type t = {
@@ -45,7 +46,7 @@ module Test = struct
           in
           Error msg
         )
-      | Q {count; arb; prop} ->
+      | Q {count; arb; prop; long_factor} ->
 
         (* create a random state from the seed *)
         let rand =
@@ -54,7 +55,7 @@ module Test = struct
         in
 
         let module Fmt = CCFormat in
-        let cell = Q.Test.make_cell ?count ~name:(str_loc self) arb prop in
+        let cell = Q.Test.make_cell ?count ?long_factor ~name:(str_loc self) arb prop in
 
         let pp_cex out (cx: _ Q.TestResult.counter_ex) =
           let {Q.TestResult.instance; shrink_steps=n; msg_l} = cx in
@@ -98,7 +99,7 @@ module type S = sig
 
   val eq : ?cmp:'a eq -> ?printer:'a print -> 'a -> 'a -> unit
 
-  val q : ?count:int -> 'a Q.arbitrary -> ('a -> bool) -> unit
+  val q : ?count:int -> ?long_factor:int -> 'a Q.arbitrary -> ('a -> bool) -> unit
 
   val assert_equal :
     ?printer:('a -> string) -> ?cmp:('a -> 'a -> bool) ->
@@ -130,8 +131,8 @@ module Make_test(X:sig val file: string end) = struct
   let eq ?cmp ?printer lhs rhs : unit =
     add_ @@ mk @@ Test.Eq {eq=cmp; print=printer; lhs; rhs}
 
-  let q ?count arb prop : unit =
-    add_ @@ mk @@ Test.Q {arb; prop; count}
+  let q ?count ?long_factor arb prop : unit =
+    add_ @@ mk @@ Test.Q {arb; prop; count; long_factor}
 
   let assert_equal ?printer ?(cmp=(=)) x y : unit =
     if not @@ cmp x y then (
diff --git a/src/testlib/containers_testlib.mli b/src/testlib/containers_testlib.mli
index 2084c11f..217c9331 100644
--- a/src/testlib/containers_testlib.mli
+++ b/src/testlib/containers_testlib.mli
@@ -13,7 +13,7 @@ module type S = sig
 
   val eq : ?cmp:'a eq -> ?printer:'a print -> 'a -> 'a -> unit
 
-  val q : ?count:int -> 'a Q.arbitrary -> ('a -> bool) -> unit
+  val q : ?count:int -> ?long_factor:int -> 'a Q.arbitrary -> ('a -> bool) -> unit
 
   val assert_equal :
     ?printer:('a -> string) -> ?cmp:('a -> 'a -> bool) ->
diff --git a/src/unix/CCUnix.ml b/src/unix/CCUnix.ml
index c3c10352..aadeb43a 100644
--- a/src/unix/CCUnix.ml
+++ b/src/unix/CCUnix.ml
@@ -50,12 +50,6 @@ let escape_str s =
     Buffer.contents buf
   ) else s
 
-(*$T
-  escape_str "foo" = "foo"
-  escape_str "foo bar" = "'foo bar'"
-  escape_str "fo'o b'ar" = "'fo'\\''o b'\\''ar'"
-*)
-
 let read_all ?(size=1024) ic =
   let buf = ref (Bytes.create size) in
   let len = ref 0 in
@@ -113,12 +107,6 @@ let call_full ?bufsize ?stdin ?env cmd =
         method errcode = int_of_process_status status
       end)
 
-(*$T
-  call_full ~stdin:(`Str "abc") "cat" |> stdout = "abc"
-  call_full "echo %s" (escape_str "a'b'c") |> stdout = "a'b'c\n"
-  call_full "echo %s" "a'b'c" |> stdout = "abc\n"
-*)
-
 let call ?bufsize ?stdin ?env cmd =
   call_full_inner ?bufsize ?stdin ?env cmd
     ~f:(fun (out,err,status) -> out, err, int_of_process_status status)
@@ -127,12 +115,6 @@ let call_stdout ?bufsize ?stdin ?env cmd =
   call_full_inner ?bufsize ?stdin ?env cmd
     ~f:(fun (out,_err,_status) -> out)
 
-(*$T
-  call_stdout ~stdin:(`Str "abc") "cat" = "abc"
-  call_stdout "echo %s" (escape_str "a'b'c") = "a'b'c\n"
-  call_stdout "echo %s" "a'b'c" = "abc\n"
-*)
-
 type line = string
 
 type async_call_result =
@@ -270,29 +252,6 @@ let with_file_lock ~kind filename f =
     Unix.close lock_file;
     raise e
 
-(*$R
-  let m = 200 in
-  let n = 50 in
-  let write_atom filename s =
-    with_file_lock ~kind:`Write filename
-      (fun () ->
-        CCIO.with_out ~flags:[Open_append; Open_creat]
-          filename (fun oc -> output_string oc s; flush oc))
-  in
-  let f filename =
-    for j=1 to m do
-      write_atom filename "foo\n"
-    done
-  in
-  CCIO.File.with_temp ~prefix:"containers_" ~suffix:".txt"
-    (fun filename ->
-        let a = Array.init n (fun _ -> Thread.create f filename) in
-        Array.iter Thread.join a;
-        let lines = CCIO.with_in filename CCIO.read_lines_l in
-        assert_equal ~printer:string_of_int (n * m) (List.length lines);
-        assert_bool "all valid" (List.for_all ((=) "foo") lines))
-*)
-
 module Infix = struct
   let (?|) fmt = call_full fmt
 
@@ -334,15 +293,3 @@ let with_temp_dir ?(mode=0o700) ?dir pat (f: string -> 'a) : 'a =
     )
   in
   loop 1000
-
-(*$R
-  let filename = with_temp_dir "test_containers"
-      (fun dir ->
-         let name = Filename.concat dir "test" in
-         CCIO.with_out name (fun oc -> output_string oc "content"; flush oc);
-         assert_bool ("file exists:"^name) (Sys.file_exists name);
-         name)
-  in
-  assert_bool ("file does not exist"^filename) (not (Sys.file_exists filename));
-  ()
-*)
diff --git a/tests/core/compat/dune b/tests/core/compat/dune
new file mode 100644
index 00000000..67bd6259
--- /dev/null
+++ b/tests/core/compat/dune
@@ -0,0 +1,5 @@
+
+(tests
+  (names t_compat)
+  (flags :standard -nolabels)
+  (libraries containers))
diff --git a/tests/core/compat/t_compat.ml b/tests/core/compat/t_compat.ml
new file mode 100644
index 00000000..c14764e7
--- /dev/null
+++ b/tests/core/compat/t_compat.ml
@@ -0,0 +1,9 @@
+
+(* test consistency of interfaces *)
+module type L = module type of CCEqual
+module type LL = module type of CCEqualLabels ;;
+
+ignore (module CCEqualLabels : L);;
+
+ignore (module CCEqual : LL);;
+
diff --git a/tests/core/dune b/tests/core/dune
index 44f81944..3bb08d4c 100644
--- a/tests/core/dune
+++ b/tests/core/dune
@@ -1,4 +1,6 @@
 (test
  (name t)
  (flags :standard -strict-sequence -warn-error -a+8)
- (libraries containers containers_testlib))
+ (modes native)
+ (libraries containers containers.bencode containers.unix threads
+   containers_testlib iter gen uutf))
diff --git a/tests/core/t.ml b/tests/core/t.ml
index 301e80b6..f3c74c44 100644
--- a/tests/core/t.ml
+++ b/tests/core/t.ml
@@ -13,4 +13,25 @@ Containers_testlib.run_all ~descr:"containers" [
   T_format.get();
   T_fun.get ();
   T_hash.get();
+  T_hashtbl.get();
+  T_heap.get();
+  T_IO.get();
+  T_int.get();
+  T_int32.get();
+  T_int64.get();
+  T_map.get();
+  T_nativeint.get();
+  T_option.get();
+  T_ord.get();
+  T_parse.get();
+  T_random.get();
+  T_result.get();
+  T_set.get();
+  T_seq.get();
+  T_sexp.get();
+  T_string.get();
+  T_utf8string.get();
+  T_vector.get();
+  T_bencode.get();
+  T_unix.get();
 ];;
diff --git a/tests/core/t_IO.ml b/tests/core/t_IO.ml
new file mode 100644
index 00000000..50b7b02d
--- /dev/null
+++ b/tests/core/t_IO.ml
@@ -0,0 +1,69 @@
+
+open CCIO
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+
+t @@ fun () ->
+  let s = String.make 200 'y' in
+  let s = Printf.sprintf "a\nb\n %s\nlast line\n" s in
+  File.with_temp ~prefix:"test_containers" ~suffix:""
+    (fun name ->
+      with_out name @@ fun oc ->
+      output_string oc s;
+      flush oc;
+      let s' = with_in name read_all in
+      assert_equal ~printer:(fun s->s) s s'
+    );
+    true;;
+
+q  Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
+     let l' = ref [] in
+     File.with_temp ~prefix:"test_containers" ~suffix:""
+      (fun name ->
+        with_out name @@ fun oc ->
+        write_lines_l oc l;
+        flush oc;
+        l' := with_in name read_lines_l;
+      );
+     String.concat "\n" l = String.concat "\n" !l'
+);;
+
+q  Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
+     let l' = ref [] in
+     File.with_temp ~prefix:"test_containers" ~suffix:""
+      (fun name ->
+        with_out name @@ fun oc ->
+        write_lines oc (Gen.of_list l);
+        flush oc;
+        l' := with_in name (fun ic -> read_lines_gen ic |> Gen.to_list);
+      );
+     String.concat "\n" l = String.concat "\n" !l'
+);;
+
+q  Q.(list_of_size Gen.(0 -- 40) printable_string) (fun l ->
+     let s = ref "" in
+     File.with_temp ~prefix:"test_containers1" ~suffix:""
+      (fun name1 ->
+        with_out name1 @@ fun oc1 ->
+        write_gen ~sep:"" oc1 (Gen.of_list l);
+        flush oc1;
+        File.with_temp ~prefix:"test_containers2" ~suffix:""
+          (fun name2 ->
+             with_out name2 @@ fun oc2 ->
+             CCIO.with_in name1 (fun ic1 -> copy_into ic1 oc2);
+             flush oc2;
+             s := with_in name2 read_all;);
+      );
+     String.concat "" l = !s
+);;
+
+t @@ fun () ->
+      File.walk "."
+        |> Gen.for_all
+          (function
+            | `File, f -> not (Sys.is_directory f)
+            | `Dir, f -> Sys.is_directory f
+          )
+      ;;
diff --git a/tests/core/t_bencode.ml b/tests/core/t_bencode.ml
new file mode 100644
index 00000000..377b54a8
--- /dev/null
+++ b/tests/core/t_bencode.ml
@@ -0,0 +1,57 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+open Containers_bencode;;
+
+
+eq ~printer:to_string_debug
+  (map_of_list []) (Decode.of_string_exn "de");;
+eq ~printer:to_string_debug
+  (list [int 1; int 2; string "foo"]) (Decode.of_string_exn "li1ei2e3:fooe");;
+
+module B = Containers_bencode
+
+let rec size = function
+  | Int _ | String _ -> 1
+  | List l -> List.fold_left (fun n x -> n + size x) 0 l
+  | Map m -> Str_map.fold(fun _ v n -> size v + n) m 0
+
+let g_rand_b =
+  Q.Gen.(
+    sized_size (0--7) @@ fix @@ fun self n ->
+      let str n = string_size ~gen:char (0 -- n) in
+      let base = [
+       int >|= B.int;
+       str 100 >|= B.string;
+     ] in
+    match n with
+   | 0 -> oneof base
+   | n ->
+     frequency @@
+      List.map (fun x -> 2, x) base @
+      [ 1, list_size (0 -- 10) (self (n-1)) >|= B.list;
+        1, list_size (0 -- 10) (pair (str 10) (self (n-1)) ) >|= B.map_of_list;
+      ]
+  )
+
+let rec shrink_b self = Q.(Iter.(
+  match self with
+  | Int i -> Shrink.int64 i >|= B.int64
+  | String s -> Shrink.string s >|= B.string
+  | List l -> Shrink.list ~shrink:shrink_b l >|= B.list
+  | Map l ->
+      let l = Str_map.fold (fun k v l -> (k,v) :: l) l [] in
+      Shrink.list ~shrink:(fun (k,v) ->
+        (Shrink.string k >|= fun k -> k,v) <+>
+        (shrink_b v >|= fun v -> k,v))
+        l
+      >|= B.map_of_list
+  ))
+
+let rand_b = Q.make ~print:to_string_debug ~stats:["size", size]
+~shrink:shrink_b g_rand_b ;;
+
+q rand_b (fun b ->
+    let s=Encode.to_string b in
+    equal (Decode.of_string_exn s) b) ;;
diff --git a/tests/core/t_eq.ml b/tests/core/t_eq.ml
index 19569565..7e802a0d 100644
--- a/tests/core/t_eq.ml
+++ b/tests/core/t_eq.ml
@@ -5,4 +5,4 @@ module T = (val Containers_testlib.make ~__FILE__ ())
 include T;;
 
 q Q.(let p = small_list (pair small_int bool) in pair p p) (fun (l1,l2) ->
-  CCEqual.(list (pair int bool)) l1 l2 = (l1=l2));;
+  (list (pair int bool)) l1 l2 = (l1=l2));;
diff --git a/tests/core/t_hashtbl.ml b/tests/core/t_hashtbl.ml
new file mode 100644
index 00000000..08a2ff0e
--- /dev/null
+++ b/tests/core/t_hashtbl.ml
@@ -0,0 +1,55 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+open CCHashtbl;;
+
+eq "c" (let tbl = of_list [1,"a"; 2,"b"] in get_or tbl 3 ~default:"c");;
+eq "b" (let tbl = of_list [1,"a"; 2,"b"] in get_or tbl 2 ~default:"c");;
+
+t @@ fun () -> of_list [1,"a"; 2,"b"] |> map_list (fun x y -> string_of_int x ^ y)
+    |> List.sort Stdlib.compare = ["1a"; "2b"];;
+
+t @@ fun () ->
+  let tbl = Hashtbl.create 32 in
+  update tbl ~f:(fun _ _ -> Some "1") ~k:1;
+  assert_equal (Some "1") (get tbl 1);
+  update tbl ~f:(fun _ v->match v with Some _ -> assert false | None -> Some "2") ~k:2;
+  assert_equal (Some "2") (get tbl 2);
+  assert_equal 2 (Hashtbl.length tbl);
+  update tbl ~f:(fun _ _ -> None) ~k:1;
+  assert_equal None (get tbl 1);
+  true
+;;
+
+t @@ fun () ->
+  let tbl = Hashtbl.create 32 in
+  let v1 = get_or_add tbl ~f:(fun _ -> "1") ~k:1 in
+  assert_equal "1" v1;
+  assert_equal (Some "1") (get tbl 1);
+  let v2 = get_or_add tbl ~f:(fun _ ->"2") ~k:2 in
+  assert_equal "2" v2;
+  assert_equal (Some "2") (get tbl 2);
+  assert_equal "2" (get_or_add tbl ~f:(fun _ -> assert false) ~k:2);
+  assert_equal 2 (Hashtbl.length tbl);
+  true
+;;
+
+module TI = Make(CCInt);;
+
+eq  "c" (let tbl = TI.of_list [1,"a"; 2,"b"] in TI.get_or tbl 3 ~default:"c");;
+eq  "b" (let tbl = TI.of_list [1,"a"; 2,"b"] in TI.get_or tbl 2 ~default:"c");;
+
+t @@ fun () ->
+  let tbl = TI.create 32 in
+  TI.incr tbl 1 ;
+  TI.incr tbl 2;
+  TI.incr tbl 1;
+  assert_equal 2 (TI.find tbl 1);
+  assert_equal 1 (TI.find tbl 2);
+  assert_equal 2 (TI.length tbl);
+  TI.decr tbl 2;
+  assert_equal 0 (TI.get_or tbl 2 ~default:0);
+  assert_equal 1 (TI.length tbl);
+  assert(not (TI.mem tbl 2));
+  true;;
diff --git a/tests/core/t_heap.ml b/tests/core/t_heap.ml
new file mode 100644
index 00000000..cc908f4e
--- /dev/null
+++ b/tests/core/t_heap.ml
@@ -0,0 +1,87 @@
+
+open CCHeap
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+module H = CCHeap.Make(struct
+  type t = int
+  let leq x y = x<=y
+end)
+
+let rec is_sorted l = match l with
+  | [_]
+  | [] -> true
+  | x::((y::_) as l') -> x <= y && is_sorted l'
+
+let extract_list = H.to_list_sorted;;
+
+t @@ fun () ->
+  let h = H.of_list [5;3;4;1;42;0] in
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 0 x;
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 1 x;
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 3 x;
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 4 x;
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 5 x;
+  let h, x = H.take_exn h in
+  assert_equal ~printer:string_of_int 42 x;
+  assert_raises (function H.Empty ->true| _ -> false)(fun () -> H.take_exn h);
+  true;;
+
+q ~count:30
+  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
+    (* put elements into a heap *)
+    let h = H.of_iter (Iter.of_list l) in
+    assert_equal 1_000 (H.size h);
+    let l' = extract_list h in
+    is_sorted l'
+  )
+;;
+
+(* test filter *)
+q ~count:30
+  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
+    (* put elements into a heap *)
+    let h = H.of_iter (Iter.of_list l) in
+    let h = H.filter (fun x->x mod 2=0) h in
+    assert
+      (H.to_iter h |> Iter.for_all (fun x -> x mod 2 = 0));
+    let l' = extract_list h in
+    is_sorted l'
+  );;
+
+q Q.(list_of_size Gen.(return 1_000) int) (fun l ->
+    (* put elements into a heap *)
+    let h = H.of_iter (Iter.of_list l) in
+    let l' = H.to_iter_sorted h |> Iter.to_list in
+    is_sorted l'
+) ;;
+
+q Q.(list int) (fun l ->
+    extract_list (H.of_list l) =
+      extract_list (H.of_gen (CCList.to_gen l))) ;;
+q Q.(list int) (fun l ->
+    let h = H.of_list l in
+    (H.to_gen h |> CCList.of_gen |> List.sort Stdlib.compare)
+      = (H.to_list h |> List.sort Stdlib.compare)) ;;
+
+q Q.(list int) (fun l ->
+    let h = H.of_list l in
+    (H.to_string string_of_int h)
+      = (List.sort Stdlib.compare l |> List.map string_of_int |> String.concat ","));;
+q Q.(list int) (fun l ->
+    let h = H.of_list l in
+    (H.to_string ~sep:" " string_of_int h)
+      = (List.sort Stdlib.compare l |> List.map string_of_int |> String.concat " "));;
+
+q Q.(list_of_size Gen.(return 1_000) int) (fun l ->
+    let module H' = Make_from_compare(CCInt) in
+    let h = H'.of_list l in
+    let l' = H'.to_list_sorted h in
+    is_sorted l'
+);;
diff --git a/tests/core/t_int.ml b/tests/core/t_int.ml
new file mode 100644
index 00000000..0310f337
--- /dev/null
+++ b/tests/core/t_int.ml
@@ -0,0 +1,132 @@
+
+open CCInt
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+
+eq ~printer:Q.Print.(list int) [0;1;2;3;4;5] (range 0 5 |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0]           (range 0 0 |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [5;4;3;2]     (range 5 2 |> Iter.to_list);;
+
+
+eq ~printer:Q.Print.(list int) []          (range' 0 0 |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0;1;2;3;4] (range' 0 5 |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [5;4;3]     (range' 5 2 |> Iter.to_list);;
+
+t @@ fun () -> pow 2 10 = 1024;;
+t @@ fun () -> pow 2 15 = 32768;;
+t @@ fun () -> pow 10 5 = 100000;;
+t @@ fun () -> pow 1 0 = 1;;
+t @@ fun () -> pow 0 1 = 0;;
+
+t @@ fun () -> (floor_div 3 5 = 0);;
+t @@ fun () -> (floor_div 5 5 = 1);;
+t @@ fun () -> (floor_div 20 5 = 4);;
+t @@ fun () -> (floor_div 12 5 = 2);;
+t @@ fun () -> (floor_div 0 5 = 0);;
+t @@ fun () -> (floor_div (-1) 5 = -1);;
+t @@ fun () -> (floor_div (-5) 5 = -1);;
+t @@ fun () -> (floor_div (-12) 5 = -3);;
+t @@ fun () -> (floor_div 0 (-5) = 0);;
+t @@ fun () -> (floor_div 3 (-5) = -1);;
+t @@ fun () -> (floor_div 5 (-5) = -1);;
+t @@ fun () -> (floor_div 9 (-5) = -2);;
+t @@ fun () -> (floor_div 20 (-5) = -4);;
+t @@ fun () -> (floor_div (-2) (-5) = 0);;
+t @@ fun () -> (floor_div (-8) (-5) = 1);;
+t @@ fun () -> (floor_div (-35) (-5) = 7);;
+t @@ fun () -> try ignore (floor_div 12 0); false with Division_by_zero -> true;;
+t @@ fun () -> try ignore (floor_div (-12) 0); false with Division_by_zero -> true;;
+
+q (Q.pair Q.small_signed_int Q.pos_int)
+      (fun (n, m) -> floor_div n m = int_of_float @@ floor (float n /. float m));;
+q (Q.pair Q.small_signed_int Q.pos_int)
+      (fun (n, m) -> floor_div n (-m) = int_of_float @@ floor (float n /. float (-m)));;
+
+t @@ fun () -> (rem 3 5 = 3);;
+t @@ fun () -> (rem 5 5 = 0);;
+t @@ fun () -> (rem 9 5 = 4);;
+t @@ fun () -> (rem (-1) 5 = 4);;
+t @@ fun () -> (rem (-5) 5 = 0);;
+t @@ fun () -> (rem (-20) 5 = 0);;
+t @@ fun () -> (rem (-9) 5 = 1);;
+t @@ fun () -> (rem 0 5 = 0);;
+t @@ fun () -> (rem 0 (-5) = 0);;
+t @@ fun () -> (rem 3 (-5) = -2);;
+t @@ fun () -> (rem 5 (-5) = 0);;
+t @@ fun () -> (rem 9 (-5) = -1);;
+t @@ fun () -> (rem (-2) (-5) = -2);;
+t @@ fun () -> (rem (-8) (-5) = -3);;
+t @@ fun () -> (rem (-35) (-5) = 0);;
+t @@ fun () -> try ignore (rem 12 0); false with Division_by_zero -> true;;
+t @@ fun () -> try ignore (rem (-12) 0); false with Division_by_zero -> true;;
+
+q (Q.pair Q.int Q.pos_int) (fun (n, m) -> let y = rem n m in y >= 0 && y < m);;
+q (Q.pair Q.int Q.pos_int) (fun (n, m) -> let y = rem n (-m) in y > (-m) && y <= 0);;
+q (Q.pair Q.int Q.pos_int) (fun (n, m) -> n = m * floor_div n m + rem n m);;
+q (Q.pair Q.int Q.pos_int) (fun (n, m) -> n = (-m) * floor_div n (-m) + rem n (-m));;
+
+eq None (of_string "moo");;
+eq (Some 42) (of_string "42");;
+
+eq 1 (of_float 1.2);;
+
+
+eq ~printer:CCFun.id "0b111" (to_string_binary 7);;
+eq ~printer:CCFun.id "-0b111" (to_string_binary (-7));;
+eq ~printer:CCFun.id "0b0" (to_string_binary 0);;
+
+q ~count:10_000
+  Q.int (fun n -> n = int_of_string (to_string_binary n));;
+
+(* note: the last test checks that no error occurs due to overflows. *)
+
+eq ~printer:Q.Print.(list int) [0]     (range_by ~step:1   0 0     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) []      (range_by ~step:1   5 0     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) []      (range_by ~step:2   1 0     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0;2;4] (range_by ~step:2   0 4     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0;2;4] (range_by ~step:2   0 5     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0]     (range_by ~step:~-1 0 0     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) []      (range_by ~step:~-1 0 5     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) []      (range_by ~step:~-2 0 1     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [5;3;1] (range_by ~step:~-2 5 1     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [5;3;1] (range_by ~step:~-2 5 0     |> Iter.to_list);;
+eq ~printer:Q.Print.(list int) [0]     (range_by ~step:max_int 0 2 |> Iter.to_list);;
+
+q Q.(pair small_int small_int) (fun (i,j) -> 
+    let i = min i j and j = max i j in 
+    CCList.equal CCInt.equal 
+      (CCInt.range_by ~step:1 i j |> Iter.to_list) 
+      (CCInt.range i j |> Iter.to_list) );;
+
+eq  0 (popcount 0);;
+eq  1 (popcount 1);;
+eq  (Sys.word_size-2) (popcount max_int);;
+eq  1 (popcount min_int);;
+eq  10 (popcount 0b1110010110110001010);;
+eq  5 (popcount 0b1101110000000000);;
+
+let simple_popcnt i =
+  let rec loop n i =
+    if i=0 then n
+    else if i land 0b1 = 1 then loop (n+1) (i lsr 1)
+    else loop n (i lsr 1)
+  in
+  loop 0 i ;;
+
+eq  0 (simple_popcnt 0);;
+eq  1 (simple_popcnt 1);;
+eq  (Sys.word_size-2) (simple_popcnt max_int);;
+eq  1 (simple_popcnt min_int);;
+eq  5 (simple_popcnt 0b1101110000000000);;
+
+q ~count:3_000 ~long_factor:10
+ Q.(let g = int in
+    set_gen (Gen.graft_corners g.gen [min_int; max_int; 0; -1; 1] ()) g)
+ (fun i ->
+  if simple_popcnt i <> popcount i then (
+    Q.Test.fail_reportf "on %d: simple-popcount=%d, popcount=%d"
+      i (simple_popcnt i) (popcount i)
+  );
+  true);;
diff --git a/tests/core/t_int32.ml b/tests/core/t_int32.ml
new file mode 100644
index 00000000..3f5cb40d
--- /dev/null
+++ b/tests/core/t_int32.ml
@@ -0,0 +1,66 @@
+
+open CCInt32
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+t @@ fun () -> pow 2l 10l = 1024l;;
+t @@ fun () -> pow 2l 15l = 32768l;;
+t @@ fun () -> pow 10l 5l = 100000l;;
+t @@ fun () -> pow 42l 0l = 1l;;
+t @@ fun () -> pow 0l 1l = 0l;;
+t @@ fun () -> (floor_div 3l 5l = 0l);;
+t @@ fun () -> (floor_div 5l 5l = 1l);;
+t @@ fun () -> (floor_div 20l 5l = 4l);;
+t @@ fun () -> (floor_div 12l 5l = 2l);;
+t @@ fun () -> (floor_div 0l 5l = 0l);;
+t @@ fun () -> (floor_div (-1l) 5l = -1l);;
+t @@ fun () -> (floor_div (-5l) 5l = -1l);;
+t @@ fun () -> (floor_div (-12l) 5l = -3l);;
+t @@ fun () -> (floor_div 0l (-5l) = 0l);;
+t @@ fun () -> (floor_div 3l (-5l) = -1l);;
+t @@ fun () -> (floor_div 5l (-5l) = -1l);;
+t @@ fun () -> (floor_div 9l (-5l) = -2l);;
+t @@ fun () -> (floor_div 20l (-5l) = -4l);;
+t @@ fun () -> (floor_div (-2l) (-5l) = 0l);;
+t @@ fun () -> (floor_div (-8l) (-5l) = 1l);;
+t @@ fun () -> (floor_div (-35l) (-5l) = 7l);;
+t @@ fun () -> try ignore (floor_div 12l 0l); false with Division_by_zero -> true;;
+t @@ fun () -> try ignore (floor_div (-12l) 0l); false with Division_by_zero -> true;;
+
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat))
+      (fun (n, m) -> let m = m + 1l in
+                     floor_div n m = of_float @@ floor (to_float n /. to_float m));;
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat))
+      (fun (n, m) -> let m = m + 1l in
+                     floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)));;
+
+let eq' = eq ~printer:Q.Print.(list to_string);;
+eq'  [0l;1l;2l;3l;4l;5l] (range 0l 5l |> Iter.to_list);;
+eq'  [0l]                (range 0l 0l |> Iter.to_list);;
+eq'  [5l;4l;3l;2l]       (range 5l 2l |> Iter.to_list);;
+
+(* note: the last test checks that no error occurs due to overflows. *)
+let eq'= eq~printer:Q.Print.(list to_string);;
+eq'  [0l]       (range_by ~step:1l   0l 0l      |> Iter.to_list);;
+eq'  []         (range_by ~step:1l   5l 0l      |> Iter.to_list);;
+eq'  []         (range_by ~step:2l   1l 0l      |> Iter.to_list);;
+eq'  [0l;2l;4l] (range_by ~step:2l   0l 4l      |> Iter.to_list);;
+eq'  [0l;2l;4l] (range_by ~step:2l   0l 5l      |> Iter.to_list);;
+eq'  [0l]       (range_by ~step:(neg 1l) 0l 0l  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 1l) 0l 5l  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 2l) 0l 1l  |> Iter.to_list);;
+eq'  [5l;3l;1l] (range_by ~step:(neg 2l) 5l 1l  |> Iter.to_list);;
+eq'  [5l;3l;1l] (range_by ~step:(neg 2l) 5l 0l  |> Iter.to_list);;
+eq'  [0l]       (range_by ~step:max_int 0l 2l   |> Iter.to_list);;
+
+q Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) ->
+    let i = min i j and j = max i j in
+    CCList.equal CCInt32.equal
+      (CCInt32.range_by ~step:1l i j |> Iter.to_list)
+      (CCInt32.range i j |> Iter.to_list) );;
+
+eq ~printer:CCFun.id "0b111" (to_string_binary 7l);;
+eq ~printer:CCFun.id "-0b111" (to_string_binary (-7l));;
+eq ~printer:CCFun.id "0b0" (to_string_binary 0l);;
+
diff --git a/tests/core/t_int64.ml b/tests/core/t_int64.ml
new file mode 100644
index 00000000..9fab16d7
--- /dev/null
+++ b/tests/core/t_int64.ml
@@ -0,0 +1,65 @@
+
+open CCInt64
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+t @@ fun () -> pow 2L 10L = 1024L;;
+t @@ fun () -> pow 2L 15L = 32768L;;
+t @@ fun () -> pow 10L 5L = 100000L;;
+t @@ fun () -> pow 42L 0L = 1L;;
+t @@ fun () -> pow 0L 1L = 0L;;
+t @@ fun () -> (floor_div 3L 5L = 0L);;
+t @@ fun () -> (floor_div 5L 5L = 1L);;
+t @@ fun () -> (floor_div 20L 5L = 4L);;
+t @@ fun () -> (floor_div 12L 5L = 2L);;
+t @@ fun () -> (floor_div 0L 5L = 0L);;
+t @@ fun () -> (floor_div (-1L) 5L = -1L);;
+t @@ fun () -> (floor_div (-5L) 5L = -1L);;
+t @@ fun () -> (floor_div (-12L) 5L = -3L);;
+t @@ fun () -> (floor_div 0L (-5L) = 0L);;
+t @@ fun () -> (floor_div 3L (-5L) = -1L);;
+t @@ fun () -> (floor_div 5L (-5L) = -1L);;
+t @@ fun () -> (floor_div 9L (-5L) = -2L);;
+t @@ fun () -> (floor_div 20L (-5L) = -4L);;
+t @@ fun () -> (floor_div (-2L) (-5L) = 0L);;
+t @@ fun () -> (floor_div (-8L) (-5L) = 1L);;
+t @@ fun () -> (floor_div (-35L) (-5L) = 7L);;
+t @@ fun () -> try ignore (floor_div 12L 0L); false with Division_by_zero -> true;;
+t @@ fun () -> try ignore (floor_div (-12L) 0L); false with Division_by_zero -> true;;
+
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat))
+      (fun (n, m) -> let m = m + 1L in
+      floor_div n m = of_float @@ floor (to_float n /. to_float m));;
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat))
+      (fun (n, m) -> let m = m + 1L in
+      floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)));;
+
+
+eq ~printer:Q.Print.(list to_string) [0L;1L;2L;3L;4L;5L] (range 0L 5L |> Iter.to_list);;
+eq ~printer:Q.Print.(list to_string) [0L]                (range 0L 0L |> Iter.to_list);;
+eq ~printer:Q.Print.(list to_string) [5L;4L;3L;2L]       (range 5L 2L |> Iter.to_list);;
+
+(* note: the last test checks that no error occurs due to overflows. *)
+let eq' = eq ~printer:Q.Print.(list to_string);;
+eq'  [0L]       (range_by ~step:1L   0L 0L      |> Iter.to_list);;
+eq'  []         (range_by ~step:1L   5L 0L      |> Iter.to_list);;
+eq'  []         (range_by ~step:2L   1L 0L      |> Iter.to_list);;
+eq'  [0L;2L;4L] (range_by ~step:2L   0L 4L      |> Iter.to_list);;
+eq'  [0L;2L;4L] (range_by ~step:2L   0L 5L      |> Iter.to_list);;
+eq'  [0L]       (range_by ~step:(neg 1L) 0L 0L  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 1L) 0L 5L  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 2L) 0L 1L  |> Iter.to_list);;
+eq'  [5L;3L;1L] (range_by ~step:(neg 2L) 5L 1L  |> Iter.to_list);;
+eq'  [5L;3L;1L] (range_by ~step:(neg 2L) 5L 0L  |> Iter.to_list);;
+eq'  [0L]       (range_by ~step:max_int 0L 2L   |> Iter.to_list);;
+
+q Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) ->
+    let i = min i j and j = max i j in
+    CCList.equal CCInt64.equal
+      (CCInt64.range_by ~step:1L i j |> Iter.to_list)
+      (CCInt64.range i j |> Iter.to_list) );;
+
+eq ~printer:CCFun.id "0b111" (to_string_binary 7L);;
+eq ~printer:CCFun.id "-0b111" (to_string_binary (-7L));;
+eq ~printer:CCFun.id "0b0" (to_string_binary 0L);;
diff --git a/tests/core/t_map.ml b/tests/core/t_map.ml
new file mode 100644
index 00000000..fdf8b13f
--- /dev/null
+++ b/tests/core/t_map.ml
@@ -0,0 +1,27 @@
+
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+open CCMap;;
+
+module M = CCMap.Make(String);;
+
+let eq' = eq ~printer:CCFormat.(to_string @@ Dump.(list (pair string int)));;
+eq'  ["a", 1; "b", 20]
+    (M.of_list ["b", 2; "c", 3]
+     |> M.update "a" (function _ -> Some 1)
+     |> M.update "c" (fun _ -> None)
+     |> M.update "b" (CCOption.map (fun x -> x * 10))
+    |> M.to_list |> List.sort CCOrd.poly);;
+
+module M2 = Make(CCInt);;
+
+q Q.(list (pair small_int small_int)) M2.(fun l ->
+  to_list (of_list l) = to_list (of_list_with ~f:(fun _ v _ ->v) l));;
+q Q.(list (pair small_int small_int)) M2.(fun l ->
+  to_list (of_iter @@ Iter.of_list l) =
+    to_list (of_iter_with ~f:(fun _ v _ ->v) @@ Iter.of_list l));;
+q Q.(list (pair small_int small_int)) M2.(fun l ->
+  to_list (of_seq @@ CCSeq.of_list l) =
+    to_list (of_seq_with ~f:(fun _ v _ ->v) @@ CCSeq.of_list l));;
diff --git a/tests/core/t_nativeint.ml b/tests/core/t_nativeint.ml
new file mode 100644
index 00000000..505efcd5
--- /dev/null
+++ b/tests/core/t_nativeint.ml
@@ -0,0 +1,67 @@
+
+open CCNativeint
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+
+t @@ fun () -> pow 2n 10n = 1024n;;
+t @@ fun () -> pow 2n 15n = 32768n;;
+t @@ fun () -> pow 10n 5n = 100000n;;
+t @@ fun () -> pow 42n 0n = 1n;;
+t @@ fun () -> pow 0n 1n = 0n;;
+t @@ fun () -> (floor_div 3n 5n = 0n);;
+t @@ fun () -> (floor_div 5n 5n = 1n);;
+t @@ fun () -> (floor_div 20n 5n = 4n);;
+t @@ fun () -> (floor_div 12n 5n = 2n);;
+t @@ fun () -> (floor_div 0n 5n = 0n);;
+t @@ fun () -> (floor_div (-1n) 5n = -1n);;
+t @@ fun () -> (floor_div (-5n) 5n = -1n);;
+t @@ fun () -> (floor_div (-12n) 5n = -3n);;
+t @@ fun () -> (floor_div 0n (-5n) = 0n);;
+t @@ fun () -> (floor_div 3n (-5n) = -1n);;
+t @@ fun () -> (floor_div 5n (-5n) = -1n);;
+t @@ fun () -> (floor_div 9n (-5n) = -2n);;
+t @@ fun () -> (floor_div 20n (-5n) = -4n);;
+t @@ fun () -> (floor_div (-2n) (-5n) = 0n);;
+t @@ fun () -> (floor_div (-8n) (-5n) = 1n);;
+t @@ fun () -> (floor_div (-35n) (-5n) = 7n);;
+t @@ fun () -> try ignore (floor_div 12n 0n); false with Division_by_zero -> true;;
+t @@ fun () -> try ignore (floor_div (-12n) 0n); false with Division_by_zero -> true;;
+
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) 
+      (fun (n, m) -> let m = m + 1n in 
+      floor_div n m = of_float @@ floor (to_float n /. to_float m));;
+q (Q.pair (Q.map of_int Q.small_signed_int) (Q.map of_int Q.small_nat)) 
+      (fun (n, m) -> let m = m + 1n in 
+      floor_div n (-m) = of_float @@ floor (to_float n /. to_float (-m)));;
+
+let eq' = eq ~printer:Q.Print.(list to_string);;
+eq' [0n;1n;2n;3n;4n;5n] (range 0n 5n |> Iter.to_list);;
+eq' [0n]                (range 0n 0n |> Iter.to_list);;
+eq' [5n;4n;3n;2n]       (range 5n 2n |> Iter.to_list);;
+
+(* note: the last test checks that no error occurs due to overflows. *)
+let eq' = eq ~printer:Q.Print.(list to_string);;
+eq'  [0n]       (range_by ~step:1n   0n 0n      |> Iter.to_list);;
+eq'  []         (range_by ~step:1n   5n 0n      |> Iter.to_list);;
+eq'  []         (range_by ~step:2n   1n 0n      |> Iter.to_list);;
+eq'  [0n;2n;4n] (range_by ~step:2n   0n 4n      |> Iter.to_list);;
+eq'  [0n;2n;4n] (range_by ~step:2n   0n 5n      |> Iter.to_list);;
+eq'  [0n]       (range_by ~step:(neg 1n) 0n 0n  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 1n) 0n 5n  |> Iter.to_list);;
+eq'  []         (range_by ~step:(neg 2n) 0n 1n  |> Iter.to_list);;
+eq'  [5n;3n;1n] (range_by ~step:(neg 2n) 5n 1n  |> Iter.to_list);;
+eq'  [5n;3n;1n] (range_by ~step:(neg 2n) 5n 0n  |> Iter.to_list);;
+eq'  [0n]       (range_by ~step:max_int 0n 2n   |> Iter.to_list);;
+
+q Q.(pair (map of_int small_int) (map of_int small_int)) (fun (i,j) ->
+    let i = min i j and j = max i j in
+    CCList.equal CCNativeint.equal
+      (CCNativeint.range_by ~step:1n i j |> Iter.to_list)
+      (CCNativeint.range i j |> Iter.to_list) );;
+
+
+eq ~printer:CCFun.id "0b111" (to_string_binary 7n);;
+eq ~printer:CCFun.id "-0b111" (to_string_binary (-7n));;
+eq ~printer:CCFun.id "0b0" (to_string_binary 0n);;
diff --git a/tests/core/t_option.ml b/tests/core/t_option.ml
new file mode 100644
index 00000000..60a7d1dd
--- /dev/null
+++ b/tests/core/t_option.ml
@@ -0,0 +1,25 @@
+
+open CCOption
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+eq None (filter ((=) 0) (Some 1));;
+eq (Some 0) (filter ((=) 0) (Some 0));;
+eq None (filter (fun _ -> true) None);;
+eq (try get_exn_or "ohno" (None:unit option); false with Invalid_argument s->s= "ohno");;
+t @@ fun () -> 123 = get_exn_or "yes" (Some 123);;
+t @@ fun () -> sequence_l [None; Some 1; Some 2] = None;;
+t @@ fun () -> sequence_l [Some 1; Some 2; Some 3] = Some [1;2;3];;
+t @@ fun () -> sequence_l [] = Some [];;
+t @@ fun () -> choice_iter (Iter.of_list [None; Some 1; Some 2]) = Some 1;;
+t @@ fun () -> choice_iter Iter.empty = None;;
+t @@ fun () -> choice_iter (Iter.repeat None |> Iter.take 100) = None;;
+t @@ fun () -> choice_seq (CCSeq.of_list [None; Some 1; Some 2]) = Some 1;;
+t @@ fun () -> choice_seq CCSeq.empty = None;;
+t @@ fun () -> choice_seq (CCSeq.repeat None |> CCSeq.take 100) = None;;
+t @@ fun () -> flatten None = None;;
+t @@ fun () -> flatten (Some None) = None;;
+t @@ fun () -> flatten (Some (Some 1)) = Some 1;;
+t @@ fun () -> return_if false 1 = None;;
+t @@ fun () -> return_if true 1 = Some 1;;
diff --git a/tests/core/t_ord.ml b/tests/core/t_ord.ml
new file mode 100644
index 00000000..a3dc64aa
--- /dev/null
+++ b/tests/core/t_ord.ml
@@ -0,0 +1,43 @@
+
+open CCOrd
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+t @@ fun () -> equiv 1 2;;
+t @@ fun () -> equiv ~-1 ~-10;;
+t @@ fun () -> equiv 0 0;;
+t @@ fun () -> equiv ~-1 ~-1;;
+t @@ fun () -> not (equiv 0 1);;
+t @@ fun () -> not (equiv 1 ~-1);;
+t @@ fun () -> not (equiv 1 0);;
+
+q Q.(pair int int) (fun (x,y) ->
+    (equiv x y) = (equiv y x));;
+q Q.(triple int int int) (fun (x,y,z) ->
+    if (equiv x y && equiv y z) then (equiv x z) else true);;
+
+t @@ fun () -> bool true false > 0;;
+t @@ fun () -> bool false true < 0;;
+t @@ fun () -> bool true true = 0;;
+t @@ fun () -> bool false false = 0;;
+
+q Q.(option int) (fun o -> option int None o <= 0);;
+
+t @@ fun () -> pair int string (1, "b") (2, "a") < 0;;
+t @@ fun () -> pair int string (1, "b") (0, "a") > 0;;
+t @@ fun () -> pair int string (1, "b") (1, "b") = 0;;
+t @@ fun () -> list int [1;2;3] [1;2;3;4] < 0;;
+t @@ fun () -> list int [1;2;3;4] [1;2;3] > 0;;
+t @@ fun () -> list int [1;2;3;4] [1;3;4] < 0;;
+
+q Q.(pair (list int)(list int)) CCOrd.(fun (l1,l2) ->
+  equiv (list int l1 l2) (Stdlib.compare l1 l2));;
+
+t @@ fun () -> array int [|1;2;3|] [|1;2;3;4|] < 0;;
+t @@ fun () -> array int [|1;2;3;4|] [|1;2;3|] > 0;;
+t @@ fun () -> array int [|1;2;3;4|] [|1;3;4|] < 0;;
+
+q
+  Q.(pair (array int)(array int)) CCOrd.(fun (a1,a2) ->
+    equiv (array int a1 a2) (list int (Array.to_list a1) (Array.to_list a2)));;
diff --git a/tests/core/t_parse.ml b/tests/core/t_parse.ml
new file mode 100644
index 00000000..f377bcd7
--- /dev/null
+++ b/tests/core/t_parse.ml
@@ -0,0 +1,214 @@
+
+module Tst = (val Containers_testlib.make ~__FILE__ ())
+include Tst;;
+
+open CCParse
+
+module T = struct
+  type tree = L of int | N of tree * tree
+end
+open T
+
+let mk_leaf x = L x
+let mk_node x y = N(x,y)
+
+let ptree = fix @@ fun self ->
+  skip_space *>
+  ( (char '(' *> (pure mk_node <*> self <*> self) <* char ')')
+    <|>
+    (U.int >|= mk_leaf) )
+
+let ptree' = fix_memo @@ fun self ->
+  skip_space *>
+  ( (char '(' *> (pure mk_node <*> self <*> self) <* char ')')
+    <|>
+    (U.int >|= mk_leaf) )
+
+let rec pptree = function
+  | N (a,b) -> Printf.sprintf "N (%s, %s)" (pptree a) (pptree b)
+  | L x -> Printf.sprintf "L %d" x
+
+let errpp pp = function
+  | Ok x -> "Ok " ^ pp x
+  | Error s -> "Error " ^ s
+
+let errpptree = errpp pptree
+
+let erreq eq x y = match x, y with
+  | Ok x, Ok y -> eq x y
+  | Error _ , Error _ -> true
+  | _ -> false ;;
+
+(* ### start tests ### *)
+
+eq ~printer:errpptree  (Ok (N (L 1, N (L 2, L 3))))
+    (parse_string ptree "(1 (2 3))" );;
+eq ~printer:errpptree  (Ok (N (N (L 1, L 2), N (L 3, N (L 4, L 5)))))
+    (parse_string ptree "((1 2) (3 (4 5)))" );;
+eq ~printer:errpptree  (Ok (N (L 1, N (L 2, L 3))))
+    (parse_string ptree' "(1 (2 3))" );;
+eq ~printer:errpptree  (Ok (N (N (L 1, L 2), N (L 3, N (L 4, L 5)))))
+    (parse_string ptree' "((1 2) (3 (4 5)))" );;
+
+t @@ fun () ->
+  let p = U.list ~sep:"," U.word in
+  let printer = function
+    | Ok l -> "Ok " ^ CCFormat.(to_string (Dump.list string_quoted)) l
+    | Error s -> "Error " ^ s
+  in
+  assert_equal ~printer
+    (Ok ["abc"; "de"; "hello"; "world"])
+    (parse_string p "[abc , de, hello ,world  ]");
+    true;;
+
+t @@ fun () ->
+  let test n =
+    let p = CCParse.(U.list ~sep:"," U.int) in
+
+    let l = CCList.(1 -- n) in
+    let l_printed =
+      CCFormat.(to_string (within "[" "]" (list ~sep:(return ",") int))) l in
+
+    let l' = CCParse.parse_string_exn p l_printed in
+
+    assert_equal ~printer:Q.Print.(list int) l l'
+  in
+  test 300_000;
+  true ;;
+
+t @@ fun () ->
+  let open CCParse.Infix in
+  let module P = CCParse in
+
+  let parens p = P.char '(' *> p <* P.char ')' in
+  let add = P.char '+' *> P.return (+) in
+  let sub = P.char '-' *> P.return (-) in
+  let mul = P.char '*' *> P.return ( * ) in
+  let div = P.char '/' *> P.return ( / ) in
+  let integer =
+  P.chars1_if (function '0'..'9'->true|_->false) >|= int_of_string in
+
+  let chainr1 e op =
+  P.fix (fun r ->
+    e >>= fun x -> (op <*> P.return x <*> r) <|> P.return x) in
+
+  let expr : int P.t =
+  P.fix (fun expr ->
+    let factor = parens expr <|> integer in
+    let term = chainr1 factor (mul <|> div) in
+    chainr1 term (add <|> sub)) in
+
+  assert_equal (Ok 6) (P.parse_string expr "4*1+2");
+  assert_equal (Ok 12) (P.parse_string expr "4*(1+2)");
+  true;;
+
+let eq' = eq ~printer:(errpp Q.Print.bool) ~cmp:(erreq (=)) ;;
+eq'  (Ok true) (parse_string (U.bool <* eoi) "true");;
+eq'  (Error "") (parse_string (U.bool <* eoi) "true ");;
+eq'  (Ok true) (parse_string (U.bool <* skip_white <* eoi) "true");;
+
+let eq' = eq ~printer:Q.Print.(pair int int);;
+eq' (0,5) (let p = any_char_n 5 *> pos in
+  match parse_string p "abcde   " with
+    | Ok p -> Position.line_and_column p
+    | Error _ -> assert false);;
+
+eq ~printer:Q.Print.(list @@ pair int int)
+  [(0,2); (1,3); (2,1); (3,0); (4,0); (5,2)]
+   (let p = each_line (skip_space *> pos) in
+    match parse_string p "  a\n  b\nc\n\n\n a" with
+      | Ok ps -> List.map Position.line_and_column ps
+      | Error _ -> assert false);;
+
+let eq' = eq ~printer:(errpp Q.Print.string) ~cmp:(erreq (=));;
+eq'  (Ok "abcd") (parse_string all_str "abcd");;
+eq'  (Ok "cd") (parse_string (string "ab" *> all_str) "abcd");;
+eq'  (Ok "") (parse_string (string "ab" *> all_str) "ab");;
+
+eq ~printer:(errpp Q.Print.(pair string string)) ~cmp:(erreq (=))
+  (Ok ("foobar", "")) (parse_string (both all_str all_str) "foobar");;
+
+q Q.(printable_string) (fun s ->
+      let pred = (function 'a'..'z' | 'A' .. 'Z' | '{' | '}' -> true | _ -> false) in
+      let p1 = chars1_if pred in
+      let p2 = take1_if pred >|= Slice.to_string in
+      parse_string p1 s = parse_string p2 s);;
+
+t @@ fun () ->
+  let pred = (function 'a'..'z' | 'A' .. 'Z' | '{' | '}' -> true | _ -> false) in
+  parse_string (chars_if pred) "coucou{lol} 123" = Ok "coucou{lol}" ;;
+
+t @@ fun () ->
+  let p0 = skip_white *> U.int in
+  let p = (skip_white *> char '(' *> many p0) <* (skip_white <* char ')') in
+  let printer =  CCFormat.(to_string @@ Dump.result  @@ Dump.list int) in
+  assert_equal ~printer
+    (Ok [1;2;3]) (parse_string p "(1 2 3)");
+  assert_equal ~printer
+    (Ok [1;2; -30; 4]) (parse_string p "( 1 2    -30 4 )");
+  true;;
+
+let aword = chars1_if (function 'a'..'z'|'A'..'Z'->true|_ -> false);;
+
+eq ~printer:(errpp Q.Print.(list string))
+  (Ok ["a";"b";"c"])
+  (parse_string (optional (char '/') *> sep ~by:(char '/') aword) "/a/b/c");;
+eq ~printer:(errpp Q.Print.(list string))
+  (Ok ["a";"b";"c"])
+  (parse_string (optional (char '/') *> sep ~by:(char '/') aword) "a/b/c");;
+
+eq ~printer:(errpp Q.Print.(string))
+  (Ok "abc") (parse_string (lookahead (string "ab") *> (string "abc")) "abcd");;
+
+eq ~printer:(errpp Q.Print.(string))
+  (Ok "1234") (parse_string line_str "1234\nyolo");;
+
+eq ~printer:(errpp Q.Print.(pair String.escaped String.escaped))
+  (Ok ("1234", "yolo")) (parse_string (line_str ||| line_str) "1234\nyolo\nswag");;
+
+eq ~printer:(errpp Q.Print.(list string)) ~cmp:(erreq (=))
+  (Ok ["a";"b";"c";"d,e,f"])
+    (parse_string (split_list_at_most ~on_char:',' 3 >|= List.map Slice.to_string) "a,b,c,d,e,f");;
+eq ~printer:(errpp Q.Print.(list string)) ~cmp:(erreq (=))
+  (Ok ["a";"bc"])
+    (parse_string (split_list_at_most ~on_char:',' 3 >|= List.map Slice.to_string) "a,bc");;
+
+eq ~printer:(errpp Q.Print.(list @@ list int))
+  (Ok ([[1;1];[2;2];[3;3];[]]))
+    (parse_string (each_line (sep ~by:skip_space U.int)) "1 1\n2 2\n3   3\n");;
+
+let eq' = eq ~printer:(errpp Q.Print.int) ~cmp:(erreq (=)) ;;
+eq'  (Ok 42) (parse_string U.int " 42");;
+eq'  (Ok 2) (parse_string U.int "2");;
+eq'  (Error "") (parse_string U.int "abc");;
+eq'  (Error "") (parse_string U.int "");;
+
+let eq' = eq ~printer:(errpp Q.Print.int) ~cmp:(erreq (=));;
+eq'  (Ok 15) (parse_string (U.in_paren (U.in_paren U.int)) "( ( 15) )");;
+eq'  (Ok 2) (parse_string (U.in_paren U.int) "(2)");;
+eq'  (Error "") (parse_string (U.in_paren U.int) "2");;
+eq'  (Error "") (parse_string (U.in_paren U.int) "");;
+eq'  (Ok 2) (parse_string (U.in_parens_opt U.int) "((((2))))");;
+eq'  (Ok 2) (parse_string (U.in_parens_opt U.int) "2");;
+eq'  (Ok 200) (parse_string (U.in_parens_opt U.int) "( (  200 ) )");;
+
+let eq' = eq ~printer:(errpp Q.Print.(option int)) ~cmp:(erreq (=));;
+eq'  (Ok (Some 12)) (parse_string U.(option int) " Some 12");;
+eq'  (Ok None) (parse_string U.(option int) "  None");;
+eq'  (Ok (Some 0)) (parse_string U.(option int) "Some 0");;
+eq'  (Ok (Some 0)) (parse_string U.(in_parens_opt @@ option int) "(( Some 0) )");;
+
+let eq' = eq ~printer:(errpp Q.Print.int) ~cmp:(erreq (=)) ;;
+eq'  (Ok 16) (parse_string U.hexa_int "0x10");;
+eq'  (Ok 16) (parse_string U.hexa_int "10");;
+eq'  (Error "") (parse_string U.hexa_int "x10");;
+eq'  (Error "") (parse_string U.hexa_int "0xz");;
+
+eq ~printer:(errpp Q.Print.bool) ~cmp:(erreq (=))
+  (Ok true) (parse_string U.bool "true");;
+eq ~printer:(errpp Q.Print.bool) ~cmp:(erreq (=))
+  (Ok false) (parse_string U.bool "false");;
+
+eq ~printer:Q.Print.(errpp (pair int int))
+  (Ok(1,2)) U.(parse_string (pair int int) "(1 , 2 )");;
+
diff --git a/tests/core/t_random.ml b/tests/core/t_random.ml
new file mode 100644
index 00000000..591906e9
--- /dev/null
+++ b/tests/core/t_random.ml
@@ -0,0 +1,19 @@
+
+open CCRandom
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+
+q Q.(list small_int) (fun l ->
+  l=[] || List.mem (run (pick_list l)) l);;
+
+q Q.(pair small_int small_int) (fun (i,j) ->
+    let len, n = 2+min i j, max i j in
+    let l = QCheck.Gen.generate1 (split_list n ~len) in
+    match l with None -> true | Some l -> l<> [] && List.for_all (fun x->x>0) l);;
+
+t @@ fun () ->
+  let open Containers in
+  ignore (List.random_choose [1;2;3] (Random.get_state()) : int);
+  true;;
diff --git a/tests/core/t_result.ml b/tests/core/t_result.ml
new file mode 100644
index 00000000..313b3b0b
--- /dev/null
+++ b/tests/core/t_result.ml
@@ -0,0 +1,32 @@
+
+open CCResult
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+t @@ fun () -> (Error "ohno 42") = (fail_printf "ohno %d" 42);;
+t @@ fun () -> (Error "ohno 42") = (fail_fprintf "ohno %d" 42);;
+
+eq (Error "error\ncontext:message(number 42, foo: true)")
+     (add_ctxf "message(number %d, foo: %B)" 42 true (Error "error"));;
+
+t @@ fun () ->
+  let called_with = ref None in
+  let f e = called_with := Some e in
+  iter_err f (Ok 1);
+  assert (!called_with = None);
+  iter_err f (Error 1);
+  assert (!called_with = Some 1);
+  true ;;
+
+t @@ fun () -> get_or_failwith (Ok 1) = 1;;
+t @@ fun () -> try ignore @@ get_or_failwith (Error "e"); false with Failure msg -> msg = "e";;
+
+eq (get_lazy (fun _ -> 2) (Ok 1)) (1);;
+eq (get_lazy (fun _ -> 2) (Error "error")) (2);;
+
+eq 42 (fold_ok (+) 2 (Ok 40));;
+eq 40 (fold_ok (+) 40 (Error "foo"));;
+eq (Ok []) (flatten_l []);;
+eq (Ok [1;2;3]) (flatten_l [Ok 1; Ok 2; Ok 3]);;
+eq (Error "ohno") (flatten_l [Ok 1; Error "ohno"; Ok 2; Ok 3; Error "wut"]);;
diff --git a/tests/core/t_seq.ml b/tests/core/t_seq.ml
new file mode 100644
index 00000000..2ab9e1c4
--- /dev/null
+++ b/tests/core/t_seq.ml
@@ -0,0 +1,88 @@
+
+open CCSeq
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+t @@ fun () -> repeat ~n:4 0 |> to_list = [0;0;0;0];;
+t @@ fun () -> repeat ~n:0 1 |> to_list = [];;
+t @@ fun () -> repeat 1 |> take 20 |> to_list = (repeat ~n:20 1 |> to_list);;
+t @@ fun () -> of_list [1;2;3;4] |> take_while (fun x->x < 4) |> to_list = [1;2;3];;
+
+q (Q.pair (Q.list Q.small_int) Q.small_int) (fun (l,n) ->
+    let s = of_list l in let s1, s2 = take n s, drop n s in
+    append s1 s2 |> to_list = l  );;
+
+t @@ fun () -> (map ((+) 1) (1 -- 5) |> to_list) = (2 -- 6 |> to_list);;
+t @@ fun () -> mapi (fun i x -> i,x) (1 -- 3) |> to_list = [0, 1; 1, 2; 2, 3];;
+t @@ fun () -> fmap (fun x -> if x mod 2=0 then Some (x*3) else None) (1--10) |> to_list
+    = [6;12;18;24;30];;
+
+t @@ fun () -> cycle (of_list [1;2]) |> take 5 |> to_list = [1;2;1;2;1];;
+t @@ fun () -> cycle (of_list [1; ~-1]) |> take 100_000 |> fold (+) 0 = 0;;
+t @@ fun () -> let f = function  10 -> None | x -> Some (x, x+1) in
+  unfold f 0 |> to_list = [0;1;2;3;4;5;6;7;8;9];;
+t @@ fun () -> for_all ((=) 1) (of_list []) = true;;
+t @@ fun () -> for_all ((=) 1) (of_list [0]) = false;;
+t @@ fun () -> for_all ((=) 1) (of_list [1]) = true;;
+t @@ fun () -> for_all ((=) 1) (of_list [1; 0]) = false;;
+t @@ fun () -> for_all ((=) 1) (of_list [0; 1]) = false;;
+t @@ fun () -> for_all ((=) 1) (of_list [1; 1]) = true;;
+t @@ fun () -> let l () = Cons (0, fun () -> failwith "no second element") in
+  try ignore (for_all ((=) 1) l); true with Failure _ -> false;;
+t @@ fun () -> exists ((=) 1) (of_list []) = false;;
+t @@ fun () -> exists ((=) 1) (of_list [0]) = false;;
+t @@ fun () -> exists ((=) 1) (of_list [1]) = true;;
+t @@ fun () -> exists ((=) 1) (of_list [1; 0]) = true;;
+t @@ fun () -> exists ((=) 1) (of_list [0; 1]) = true;;
+t @@ fun () -> exists ((=) 1) (of_list [0; 0]) = false;;
+t @@ fun () -> let l () = Cons (1, fun () -> failwith "no second element") in
+  try ignore (exists ((=) 1) l); true with Failure _ -> false;;
+t @@ fun () -> of_list [1;1;1;2;2;3;3;1] |> group (=)
+  |> map to_list |> to_list = [[1;1;1]; [2;2]; [3;3]; [1]];;
+t @@ fun () -> range 0 5 |> to_list = [0;1;2;3;4;5];;
+t @@ fun () -> range 0 0 |> to_list = [0];;
+t @@ fun () -> range 5 2 |> to_list = [5;4;3;2];;
+t @@ fun () -> 1 --^ 5 |> to_list = [1;2;3;4];;
+t @@ fun () -> 5 --^ 1 |> to_list = [5;4;3;2];;
+t @@ fun () -> 1 --^ 2 |> to_list = [1];;
+t @@ fun () -> 0 --^ 0 |> to_list = [];;
+
+q Q.(list (pair int int)) (fun l ->
+  let l = of_list l in let a, b = unzip l in equal (=) l (zip a b));;
+
+eq [0,'a'; 1, 'b'; 2, 'c'] (of_string "abcde" |> zip_i |> take 3 |> to_list);;
+
+q Q.(array int) (fun a -> of_array a |> to_array = a);;
+
+t @@ fun () -> of_array [| 1; 2; 3 |] |> to_list = [1;2;3];;
+t @@ fun () -> of_list [1;2;3] |> to_array = [| 1; 2; 3; |];;
+t @@ fun () ->
+  let r = ref 1 in
+  let s = unfold (fun i -> if i < 3 then let x = !r in incr r; Some (x, succ i) else None) 0 in
+  to_array s = [| 1; 2; 3; |];;
+
+t @@ fun () ->
+  let g = let n = ref 0 in fun () -> Some (incr n; !n) in
+  let l = of_gen g in
+  assert_equal [1;2;3;4;5;6;7;8;9;10] (take 10 l |> to_list);
+  assert_equal [1;2;3;4;5;6;7;8;9;10] (take 10 l |> to_list);
+  assert_equal [11;12] (drop 10 l |> take 2 |> to_list);
+  true;;
+
+t @@ fun () ->
+  let printer = Q.Print.(list int) in
+  let gen () =
+    let rec l = let r = ref 0 in fun () -> incr r; Cons (!r, l) in l
+  in
+  let l1 = gen () in
+  assert_equal ~printer [1;2;3;4] (take 4 l1 |> to_list);
+  assert_equal ~printer [5;6;7;8] (take 4 l1 |> to_list);
+  let l2 = gen () |> memoize in
+  assert_equal ~printer [1;2;3;4] (take 4 l2 |> to_list);
+  assert_equal ~printer [1;2;3;4] (take 4 l2 |> to_list);
+  true;;
+
+t @@ fun () -> interleave (of_list [1;3;5]) (of_list [2;4;6]) |> to_list = [1;2;3;4;5;6];;
+t @@ fun () -> fair_app (of_list [(+)1; ( * ) 3]) (of_list [1; 10])
+    |> to_list |> List.sort Stdlib.compare = [2; 3; 11; 30];;
diff --git a/tests/core/t_set.ml b/tests/core/t_set.ml
new file mode 100644
index 00000000..4bfa330d
--- /dev/null
+++ b/tests/core/t_set.ml
@@ -0,0 +1,22 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+module S = CCSet.Make(struct
+  type t = int
+  let compare x y = Stdlib.compare x y
+end);;
+
+eq ~printer:(fun s -> s)
+  (S.to_string string_of_int (S.of_list [4; 3])) "3,4";;
+
+q Q.(list int) (fun l ->
+    let s = S.of_list l in
+    (S.to_string string_of_int s)
+      = (CCList.sort_uniq ~cmp:CCInt.compare l
+         |> List.map string_of_int |> String.concat ","));;
+q Q.(list int) (fun l ->
+    let s = S.of_list l in
+    (S.to_string ~sep:" " string_of_int s)
+      = (CCList.sort_uniq ~cmp:CCInt.compare l
+         |> List.map string_of_int |> String.concat " "));;
diff --git a/tests/core/t_sexp.ml b/tests/core/t_sexp.ml
new file mode 100644
index 00000000..f0004b43
--- /dev/null
+++ b/tests/core/t_sexp.ml
@@ -0,0 +1,80 @@
+
+open CCSexp
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+
+t @@ fun () -> CCResult.to_opt (parse_string "(abc d/e/f \"hello \\\" () world\" )") <> None;;
+t @@ fun () -> CCResult.to_opt (parse_string "(abc ( d e ffff   ) \"hello/world\")") <> None;;
+t @@ fun () -> CCResult.to_opt (parse_string "\"\123\bcoucou\"") <> None;;
+
+let eq' = eq ~printer:(function Ok x -> to_string x | Error e -> "error " ^ e);;
+eq'  (parse_string "(a b)") (Ok (`List [`Atom "a"; `Atom "b"]));;
+eq'  (parse_string "(a\n ;coucou\n b)") (Ok (`List [`Atom "a"; `Atom "b"]));;
+eq'  (parse_string "(a #; (foo bar\n (1 2 3)) b)") (Ok (`List [`Atom "a"; `Atom "b"]));;
+eq'  (parse_string "#; (a b) (c d)") (Ok (`List [`Atom "c"; `Atom "d"]));;
+eq'  (parse_string "#; (a b) 1") (Ok (`Atom "1"));;
+
+let eq' = eq ~printer:(function Ok x -> String.concat ";" @@ List.map to_string x | Error e -> "error " ^ e) ;;
+eq'  (parse_string_list "(a b)(c)") (Ok [`List [`Atom "a"; `Atom "b"]; `List [`Atom "c"]]);;
+eq'  (parse_string_list "  ") (Ok []);;
+eq'  (parse_string_list "(a\n ;coucou\n b)") (Ok [`List [`Atom "a"; `Atom "b"]]);;
+eq'  (parse_string_list "#; (a b) (c d) e ") (Ok [`List [`Atom "c"; `Atom "d"]; `Atom "e"]);;
+eq'  (parse_string_list "#; (a b) 1") (Ok [`Atom "1"]);;
+
+let sexp_bijective s = to_string s |> parse_string = Ok s;;
+
+eq ~printer:CCFormat.(to_string (Dump.result pp))
+  (Ok (`List [`Atom ""])) (parse_string "(\"\")");;
+
+t @@ fun () -> sexp_bijective (`List [`Atom ""]);;
+
+let sexp_gen =
+  let mkatom a = `Atom a and mklist l = `List l in
+  let atom = Q.Gen.(map mkatom (string_size ~gen:printable (1 -- 30))) in
+  let gen = Q.Gen.(
+    sized (fix
+      (fun self n st -> match n with
+      | 0 -> atom st
+      | _ ->
+        frequency
+          [ 1, atom
+          ; 2, map mklist (list_size (0 -- 10) (self (n/10)))
+          ] st
+      )
+  )) in
+  let rec small = function
+    | `Atom s -> String.length s
+    |  `List l -> List.fold_left (fun n x->n+small x) 0 l
+  and print = function
+    | `Atom s -> Printf.sprintf "`Atom \"%s\"" s
+    | `List l -> "`List " ^ Q.Print.list print l
+  and shrink = function
+    | `Atom s -> Q.Iter.map mkatom (Q.Shrink.string s)
+    | `List l -> Q.Iter.map mklist (Q.Shrink.list ~shrink l)
+  in
+  Q.make ~print ~small ~shrink gen;;
+
+q ~count:100 sexp_gen sexp_bijective;;
+
+(* regression for #338 *)
+t @@ fun () ->
+  Printexc.record_backtrace true;
+  let cases = [
+    "\"\\256\"";
+    "\"\\722\02622222\\\\\n\r<\\\\\\\\\"\\222222222\\\\\"\"\2032!2222\\\\\"\"";
+    "\"\n\r<\\t\023\n\203\\622222222\\\\\"\"\2032!2222\\\\\"\"";
+    "\"\n\r<@t\023\n\203\\2222D2\n\r22222\01622222222222222222222222\203\\292242\222 2\\\\\">K2";
+    "\"\n\r<\\t\023\n\203\\272222222\\\\\"\"\2032\0042222\\\\\"\"";
+    "\"\023\n\203\\5222\n\r<\\t\023\n\203\\52222222\\\\\"2\\\216\216\216\216\216\\\\\"\216\216\216\216\216\216\216\216\216222222222222222\147";
+    "\"\\722\02622222\\\\\n\r<\\\\\\\\\"\\222222222\\\\\"\"\2032!2222\\\\\"\"";
+  ] in
+  cases
+  |> List.iter (fun s ->
+    try ignore (parse_string s);
+    with e ->
+      let st = Printexc.get_backtrace() in
+      print_endline @@ Printexc.to_string e ^ "\n" ^ st;
+      assert false);
+  true;;
diff --git a/tests/core/t_string.ml b/tests/core/t_string.ml
new file mode 100644
index 00000000..71a1f35e
--- /dev/null
+++ b/tests/core/t_string.ml
@@ -0,0 +1,264 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+open CCString;;
+
+open CCShims_.Stdlib;;
+
+q Q.printable_string (fun s -> s = rev (rev s));;
+q Q.printable_string (fun s -> length s = length (rev s));;
+q Q.printable_string (fun s -> rev s = (to_list s |> List.rev |> of_list));;
+
+
+eq  "abc" (rev "cba");;
+eq  "" (rev "");;
+eq  " " (rev " ");;
+
+let eq' = eq ~printer:string_of_int;;
+eq'  1 (find ~sub:"bc" "abcd");;
+eq'  ~-1 (find ~sub:"bc" "abd");;
+eq'  1 (find ~sub:"a" "_a_a_a_");;
+eq'  6 (find ~start:5 ~sub:"a" "a1a234a");;
+
+q ~count:10_000
+  Q.(pair printable_string printable_string) (fun (s1,s2) ->
+    let i = find ~sub:s2 s1 in
+    i < 0 || String.sub s1 i (length s2) = s2);;
+
+let eq' = eq ~printer:Q.Print.(list int);;
+eq'  [1; 6] (find_all_l ~sub:"bc" "abc aabc  aab");;
+eq'  [] (find_all_l ~sub:"bc" "abd");;
+eq'  [76] (find_all_l ~sub:"aaaaaa"
+    "aabbaabbaaaaabbbbabababababbbbabbbabbaaababbbaaabaabbaabbaaaabbababaaaabbaabaaaaaabbbaaaabababaabaaabbaabaaaabbababbaabbaaabaabbabababbbaabababaaabaaababbbaaaabbbaabaaababbabaababbaabbaaaaabababbabaababbbaaabbabbabababaaaabaaababaaaaabbabbaabbabbbbbbbbbbbbbbaabbabbbbbabbaaabbabbbbabaaaaabbababbbaaaa");;
+
+t @@ fun () -> mem ~sub:"bc" "abcd";;
+t @@ fun () -> not (mem ~sub:"a b" "abcd");;
+
+let eq' = eq ~printer:string_of_int ;;
+eq'  1 (rfind ~sub:"bc" "abcd");;
+eq'  ~-1 (rfind ~sub:"bc" "abd");;
+eq'  5 (rfind ~sub:"a" "_a_a_a_");;
+eq'  4 (rfind ~sub:"bc" "abcdbcd");;
+eq'  6 (rfind ~sub:"a" "a1a234a");;
+
+q ~count:10_000
+  Q.(pair printable_string printable_string) (fun (s1,s2) ->
+    let i = rfind ~sub:s2 s1 in
+    i < 0 || String.sub s1 i (length s2) = s2);;
+
+
+eq ~printer:CCFun.id (replace ~which:`All ~sub:"a" ~by:"b" "abcdabcd") "bbcdbbcd";;
+eq ~printer:CCFun.id (replace ~which:`Left ~sub:"a" ~by:"b" "abcdabcd") "bbcdabcd";;
+eq ~printer:CCFun.id (replace ~which:`Right ~sub:"a" ~by:"b" "abcdabcd") "abcdbbcd";;
+eq ~printer:CCFun.id (replace ~which:`All ~sub:"ab" ~by:"hello" "  abab cdabb a")
+    "  hellohello cdhellob a";;
+eq ~printer:CCFun.id (replace ~which:`Left ~sub:"ab" ~by:"nope" " a b c d ") " a b c d ";;
+eq ~printer:CCFun.id (replace ~sub:"a" ~by:"b" "1aa234a") "1bb234b";;
+
+t @@ fun () -> Split.list_cpy ~by:"," "aa,bb,cc" = ["aa"; "bb"; "cc"];;
+t @@ fun () -> Split.list_cpy ~by:"--" "a--b----c--" = ["a"; "b"; ""; "c"; ""];;
+t @@ fun () -> Split.list_cpy ~by:" " "hello  world aie" = ["hello"; ""; "world"; "aie"];;
+t @@ fun () -> Split.left ~by:" " "ab cde f g " = Some ("ab", "cde f g ");;
+t @@ fun () -> Split.left ~by:"__" "a__c__e_f" = Some ("a", "c__e_f");;
+t @@ fun () -> Split.left ~by:"_" "abcde" = None;;
+t @@ fun () -> Split.left ~by:"bb" "abbc" = Some ("a", "c");;
+t @@ fun () -> Split.left ~by:"a_" "abcde" = None;;
+t @@ fun () -> Split.right ~by:" " "ab cde f g" = Some ("ab cde f", "g");;
+t @@ fun () -> Split.right ~by:"__" "a__c__e_f" = Some ("a__c", "e_f");;
+t @@ fun () -> Split.right ~by:"_" "abcde" = None;;
+t @@ fun () -> Split.right ~by:"a_" "abcde" = None;;
+
+eq ~printer:Q.Print.(list string)
+  ["a"; "few"; "words"; "from"; "our"; "sponsors"]
+  (split_on_char ' ' "a few words from our sponsors");;
+
+q Q.(printable_string) (fun s ->
+    let s = split_on_char ' ' s |> String.concat " " in
+    s = (split_on_char ' ' s |> String.concat " "));;
+
+t @@ fun () -> compare_versions "0.1.3" "0.1" > 0;;
+t @@ fun () -> compare_versions "10.1" "2.0" > 0;;
+t @@ fun () -> compare_versions "0.1.alpha" "0.1" > 0;;
+t @@ fun () -> compare_versions "0.3.dev" "0.4" < 0;;
+t @@ fun () -> compare_versions "0.foo" "0.0" < 0;;
+t @@ fun () -> compare_versions "1.2.3.4" "01.2.4.3" < 0;;
+
+q Q.(pair printable_string printable_string) (fun (a,b) ->
+  CCOrd.equiv (compare_versions a b) (CCOrd.opp compare_versions b a));;
+
+t @@ fun () -> compare_natural "foo1" "foo2" < 0;;
+t @@ fun () -> compare_natural "foo11" "foo2" > 0;;
+t @@ fun () -> compare_natural "foo11" "foo11" = 0;;
+t @@ fun () -> compare_natural "foo011" "foo11" = 0;;
+t @@ fun () -> compare_natural "foo1a" "foo1b" < 0;;
+t @@ fun () -> compare_natural "foo1a1" "foo1a2" < 0;;
+t @@ fun () -> compare_natural "foo1a17" "foo1a2" > 0;;
+
+q Q.(pair printable_string printable_string) (fun (a,b) ->
+  CCOrd.opp compare_natural a b = compare_natural b a);;
+q Q.(printable_string) (fun a -> compare_natural a a = 0);;
+q Q.(triple printable_string printable_string printable_string) (fun (a,b,c) ->
+    if compare_natural a b < 0 && compare_natural b c < 0
+    then compare_natural a c < 0 else Q.assume_fail());;
+
+q Q.(string_of_size Gen.(0 -- 30)) (fun s ->
+    edit_distance s s = 0);;
+q Q.(let p = string_of_size Gen.(0 -- 20) in pair p p) (fun (s1,s2) ->
+    edit_distance s1 s2 = edit_distance s2 s1);;
+q Q.(let p = string_of_size Gen.(0 -- 20) in pair p p) (fun (s1,s2) ->
+    let e = edit_distance s1 s2 in
+    let e' = edit_distance ~cutoff:3 s1 s2 in
+    (if e' < 3 then e=e' else e >= 3) &&
+    (if e <= 3 then e=e' else true));;
+
+eq ~printer:string_of_int 2 (edit_distance "hello" "helo!");;
+eq ~printer:string_of_int 5 (edit_distance "abcde" "tuvwx");;
+eq ~printer:string_of_int 2 (edit_distance ~cutoff:2 "abcde" "tuvwx");;
+eq ~printer:string_of_int 1
+  (edit_distance ("a" ^ String.make 100 '_') ("b"^String.make 100 '_'));;
+eq ~printer:string_of_int 1
+  (edit_distance ~cutoff:4 ("a" ^ String.make 1000 '_') ("b"^String.make 1000 '_'));;
+eq ~printer:string_of_int 2
+  (edit_distance ~cutoff:3 ("a" ^ String.make 1000 '_' ^ "c")
+       ("b" ^ String.make 1000 '_' ^ "d"));;
+
+(* test that building a from s, and mutating one char of s, yields
+   a string s' that is accepted by a.
+
+   --> generate triples (s, i, c) where c is a char, s a non empty string
+   and i a valid index in s.
+*)
+
+q (
+    let gen = Q.Gen.(
+      3 -- 10 >>= fun len ->
+      0 -- (len-1) >>= fun i ->
+      string_size (return len) >>= fun s ->
+      char >|= fun c -> (s,i,c)
+    ) in
+    let small (s,_,_) = String.length s in
+    Q.make ~small gen
+  )
+  (fun (s,i,c) ->
+    let s' = Bytes.of_string s in
+    Bytes.set s' i c;
+    edit_distance s (Bytes.to_string s') <= 1)
+;;
+
+t @@ fun () -> prefix ~pre:"aab" "aabcd";;
+t @@ fun () -> not (prefix ~pre:"ab" "aabcd");;
+t @@ fun () -> not (prefix ~pre:"abcd" "abc");;
+t @@ fun () -> prefix ~pre:"abc" "abcde";;
+t @@ fun () -> prefix ~pre:"" "";;
+t @@ fun () -> prefix ~pre:"" "abc";;
+t @@ fun () -> prefix ~pre:"abc" "abc";;
+t @@ fun () -> suffix ~suf:"cd" "abcd";;
+t @@ fun () -> suffix ~suf:"" "";;
+t @@ fun () -> suffix ~suf:"" "abc";;
+t @@ fun () -> not (suffix ~suf:"cd" "abcde");;
+t @@ fun () -> not (suffix ~suf:"abcd" "cd");;
+
+eq  ("ab", "cd") (take_drop 2 "abcd");;
+eq  ("abc", "") (take_drop 3 "abc");;
+eq  ("abc", "") (take_drop 5 "abc");;
+
+let eq' = eq ~printer:Q.Print.(option string);;
+eq'  (Some "ab") (chop_suffix ~suf:"cd" "abcd");;
+eq'  None (chop_suffix ~suf:"cd" "abcde");;
+eq'  None (chop_suffix ~suf:"abcd" "cd");;
+eq'  (Some "cd") (chop_prefix ~pre:"aab" "aabcd");;
+eq'  None (chop_prefix ~pre:"ab" "aabcd");;
+eq'  None (chop_prefix ~pre:"abcd" "abc");;
+
+let eq' = eq ~printer:Q.Print.string;;
+eq'  "  42" (pad 4 "42");;
+eq'  "0042" (pad ~c:'0' 4 "42");;
+eq'  "4200" (pad ~side:`Right ~c:'0' 4 "42");;
+eq'  "hello" (pad 4 "hello");;
+eq'  "aaa" (pad ~c:'a' 3 "");;
+eq'  "aaa" (pad ~side:`Right ~c:'a' 3 "");;
+
+t @@ fun () -> of_list ['a'; 'b'; 'c'] = "abc";;
+t @@ fun () -> of_list [] = "";;
+
+let eq' = eq ~printer:Q.Print.(list @@ Printf.sprintf "%S");;
+eq'  ["ab"; "c"] (lines "ab\nc");;
+eq'  ["ab"; "c"] (lines "ab\nc\n");;
+eq'  [] (lines "");;
+eq'  [""] (lines "\n");;
+eq'  [""; "a"] (lines "\na");;
+
+q Q.(printable_string) (fun s ->
+  lines s = (lines_gen s |> Gen.to_list));;
+q Q.(printable_string) (fun s ->
+  lines s = (lines_iter s |> Iter.to_list));;
+
+q Q.(small_list printable_string) (fun l ->
+  concat_iter ~sep:"\n" (Iter.of_list l) = concat "\n" l);;
+q Q.(small_list printable_string) (fun l ->
+  concat_gen ~sep:"\n" (Gen.of_list l) = concat "\n" l);;
+q Q.(small_list printable_string) (fun l ->
+  concat_seq ~sep:"\n" (CCSeq.of_list l) = concat "\n" l);;
+
+eq ~printer:CCFun.id "" (unlines []);;
+eq ~printer:CCFun.id   "ab\nc\n" (unlines ["ab"; "c"]);;
+
+q Q.printable_string (fun s -> trim (unlines (lines s)) = trim s);;
+q Q.printable_string (fun s -> trim (unlines_gen (lines_gen s)) = trim s);;
+
+q Q.(small_list small_string) (fun l ->
+    let l = unlines l |> lines in
+    l = (unlines l |> lines));;
+
+t @@ fun () -> set "abcd" 1 '_' = "a_cd";;
+t @@ fun () -> set "abcd" 0 '-' = "-bcd";;
+t @@ fun () -> (try ignore (set "abc" 5 '_'); false with Invalid_argument _ -> true);;
+
+eq ~printer:Q.Print.string
+  "bcef" (filter_map
+     (function 'c' -> None | c -> Some (Char.chr (Char.code c + 1))) "abcde");;
+
+eq ~printer:Q.Print.string
+  "abde" (filter (function 'c' -> false | _ -> true) "abcdec");;
+
+q Q.printable_string (fun s -> filter (fun _ -> true) s = s);;
+
+eq ~printer:Q.Print.string
+  "abcde" (uniq CCShims_.Stdlib.(=) "abbccdeeeee");;
+
+eq ~printer:CCFun.id "abc " (ltrim " abc ");;
+eq ~printer:CCFun.id   " abc" (rtrim " abc ");;
+
+q Q.(printable_string) (fun s ->
+    String.trim s = (s |> ltrim |> rtrim));;
+q Q.(printable_string) (fun s -> ltrim s = ltrim (ltrim s));;
+q Q.(printable_string) (fun s -> rtrim s = rtrim (rtrim s));;
+q Q.(printable_string) (fun s ->
+    let s' = ltrim s in
+    if s'="" then Q.assume_fail() else s'.[0] <> ' ');;
+q Q.(printable_string) (fun s ->
+    let s' = rtrim s in
+    if s'="" then Q.assume_fail() else s'.[String.length s'-1] <> ' ');;
+
+t @@ fun () -> equal_caseless "foo" "FoO";;
+t @@ fun () -> equal_caseless "helLo" "HEllO";;
+
+q Q.(pair printable_string printable_string) (fun (s1,s2) ->
+    equal_caseless s1 s2 = (lowercase_ascii s1=lowercase_ascii s2));;
+q Q.(printable_string) (fun s -> equal_caseless s s);;
+q Q.(printable_string) (fun s -> equal_caseless (uppercase_ascii s) s);;
+
+let eq' = eq ~printer:(Printf.sprintf "%S");;
+eq'  "0068656c6c6f20776f726c64" (to_hex "\000hello world");;
+eq'  "" (to_hex "");;
+eq'  "\000hello world" (of_hex_exn "0068656c6c6f20776f726c64");;
+eq'  "hello world" (of_hex_exn "68656C6C6F20776F726C64");;
+
+q Q.(string) (fun s ->
+  of_hex_exn (to_hex s) = s);;
+q Q.(string) (fun s ->
+    CCString.for_all (function 'A'..'F'|'a'..'f'|'0'..'9' -> true |  _ -> false) @@ to_hex s);;
+
+t @@ fun () -> "ab" < "abc";;
+t @@ fun () -> "123" < "14";;
diff --git a/tests/core/t_unix.ml b/tests/core/t_unix.ml
new file mode 100644
index 00000000..a37fcb2e
--- /dev/null
+++ b/tests/core/t_unix.ml
@@ -0,0 +1,48 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+open CCUnix;;
+
+t @@ fun () -> escape_str "foo" = "foo";;
+t @@ fun () -> escape_str "foo bar" = "'foo bar'";;
+t @@ fun () -> escape_str "fo'o b'ar" = "'fo'\\''o b'\\''ar'";;
+t @@ fun () -> call_full ~stdin:(`Str "abc") "cat" |> stdout = "abc";;
+t @@ fun () -> call_full "echo %s" (escape_str "a'b'c") |> stdout = "a'b'c\n";;
+t @@ fun () -> call_full "echo %s" "a'b'c" |> stdout = "abc\n";;
+t @@ fun () -> call_stdout ~stdin:(`Str "abc") "cat" = "abc";;
+t @@ fun () -> call_stdout "echo %s" (escape_str "a'b'c") = "a'b'c\n";;
+t @@ fun () -> call_stdout "echo %s" "a'b'c" = "abc\n";;
+
+t @@ fun () ->
+  let m = 200 in
+  let n = 50 in
+  let write_atom filename s =
+    with_file_lock ~kind:`Write filename
+      (fun () ->
+        CCIO.with_out ~flags:[Open_append; Open_creat]
+          filename (fun oc -> output_string oc s; flush oc))
+  in
+  let f filename =
+    for _j=1 to m do
+      write_atom filename "foo\n"
+    done
+  in
+  CCIO.File.with_temp ~prefix:"containers_" ~suffix:".txt"
+    (fun filename ->
+        let a = Array.init n (fun _ -> Thread.create f filename) in
+        Array.iter Thread.join a;
+        let lines = CCIO.with_in filename CCIO.read_lines_l in
+        assert_equal ~printer:string_of_int (n * m) (List.length lines);
+        assert (List.for_all ((=) "foo") lines));
+  true;;
+
+t @@ fun () ->
+  let filename = with_temp_dir "test_containers"
+      (fun dir ->
+         let name = Filename.concat dir "test" in
+         CCIO.with_out name (fun oc -> output_string oc "content"; flush oc);
+         assert (Sys.file_exists name);
+         name)
+  in
+  assert (not (Sys.file_exists filename));
+  true;;
diff --git a/tests/core/t_utf8string.ml b/tests/core/t_utf8string.ml
new file mode 100644
index 00000000..deb7bee7
--- /dev/null
+++ b/tests/core/t_utf8string.ml
@@ -0,0 +1,162 @@
+
+open CCUtf8_string
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+
+eq ~cmp:(=) ~printer:Q.Print.(list (fun c -> string_of_int@@ Uchar.to_int c))
+  (to_list (of_string_exn "aébõ😀")) (to_seq (of_string_exn "aébõ😀") |> CCList.of_seq);;
+
+(* make sure it's persisted correctly *)
+t @@ fun () ->
+  let s = (of_string_exn "aébõ😀") in
+  let seq = to_seq s in
+  let l = to_list s in
+  let testeq seq = assert_equal ~cmp:(=) l (CCList.of_seq seq) in
+  testeq seq;
+  testeq seq;
+  testeq seq;
+  true;;
+
+let printer s = String.escaped (to_string s)
+let pp_uchar (c:Uchar.t) = Printf.sprintf "0x%x" (Uchar.to_int c)
+
+let arb_uchar =
+  let rec gen  = lazy (
+    let open Q.Gen in
+    Q.Gen.int_range Uchar.(to_int min) Uchar.(to_int max) >>= fun n ->
+    try return (Uchar.of_int n)
+    with _ -> Lazy.force gen
+  ) in
+  Q.make
+    ~print:(fun c -> Printf.sprintf "<uchar '%d'>" (Uchar.to_int c))
+    (Lazy.force gen)
+
+let uutf_is_valid s =
+try
+  Uutf.String.fold_utf_8
+    (fun () _ -> function
+       | `Malformed _ -> raise Exit
+       | `Uchar _ -> ())
+    () s;
+  true
+with Exit ->
+  false
+
+let uutf_to_iter s f =
+Uutf.String.fold_utf_8
+  (fun () _ -> function
+     | `Malformed _ -> f (Uchar.of_int 0xfffd)
+     | `Uchar c -> f c)
+    () s
+
+let uutf_of_l l =
+  let buf = Buffer.create 32 in
+  List.iter (Uutf.Buffer.add_utf_8 buf) l;
+  Buffer.contents buf;;
+
+t @@ fun () ->
+  let s = of_string_exn "このため、" in
+  let s' = to_iter s |> of_iter in
+  assert_equal ~cmp:equal ~printer s s';
+  true;;
+
+q Q.small_string (fun s ->
+    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
+    is_valid s);;
+
+q ~long_factor:10
+  Q.small_string (fun s ->
+    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
+    s = (of_string_exn s |> to_iter|> of_iter|> to_string)
+  );;
+
+q ~long_factor:10
+  Q.string (fun s ->
+    Q.assume (CCString.for_all (fun c -> Char.code c < 128) s);
+    String.length s = List.length (of_string_exn s |> to_list)
+  );;
+
+q ~long_factor:10 ~count:20_000
+  Q.(small_list arb_uchar) (fun l ->
+      let s = of_list l in
+      l = to_list s);;
+
+q ~long_factor:10
+  Q.(small_list arb_uchar) (fun l ->
+      let s = of_list l in
+      l = (to_list @@ of_gen @@ to_gen s)
+  );;
+
+q ~long_factor:10
+  Q.(small_list arb_uchar) (fun l ->
+      let s = of_list l in
+      l = (to_list @@ of_iter @@ to_iter s)
+  );;
+
+t @@ fun () -> not (is_valid "\192\181");;
+t @@ fun () -> not (is_valid "\193\143");;
+t @@ fun () -> not (is_valid "\224\151\167");;
+t @@ fun () -> not (is_valid "\224\137\165");;
+t @@ fun () -> is_valid "\240\151\189\163";;
+
+q ~long_factor:40
+  Q.string (fun s ->
+    Q.assume (is_valid s);
+    let s = of_string_exn s in
+    let s2 = s |> to_iter|> of_iter in
+    if s=s2 then true
+    else Q.Test.fail_reportf "s=%S, s2=%S" (to_string s)(to_string s2)
+  );;
+
+q ~long_factor:40
+  Q.string (fun s ->
+    Q.assume (is_valid s);
+    let s = of_string_exn s in
+    let s2 = s |> to_gen |> of_gen in
+    if s=s2 then true
+    else Q.Test.fail_reportf "s=%S, s2=%S" (to_string s)(to_string s2)
+  );;
+
+(* compare with uutf *)
+
+q ~long_factor:40 ~count:50_000
+  Q.small_string (fun s ->
+    let v1 = is_valid s in
+    let v2 = uutf_is_valid s in
+    if v1=v2 then true
+    else Q.Test.fail_reportf "s:%S, valid: %B, uutf_valid: %B" s v1 v2
+  );;
+
+q ~long_factor:40 ~count:50_000
+  Q.(small_list arb_uchar) (fun l ->
+    let pp s = Q.Print.(list pp_uchar) s in
+    let uutf = uutf_of_l l in
+    let s = (of_list l:>string) in
+    if uutf = s then true
+    else Q.Test.fail_reportf "l: '%s', uutf: '%s', containers: '%s'"
+      (pp l) uutf s
+  );;
+
+q ~long_factor:40 ~count:50_000
+  Q.small_string (fun s ->
+    Q.assume (is_valid s && uutf_is_valid s);
+    let pp s = Q.Print.(list pp_uchar) s in
+    let l_uutf = uutf_to_iter s |> Iter.to_list in
+    let l_co = of_string_exn s |> to_iter |> Iter.to_list in
+    if l_uutf = l_co then true
+    else Q.Test.fail_reportf "uutf: '%s', containers: '%s', is_valid %B, uutf_is_valid %B"
+      (pp l_uutf) (pp l_co) (is_valid s) (uutf_is_valid s)
+  );;
+
+t @@ fun () ->
+  for i = 0 to 127 do
+    let c = Uchar.of_int i in
+    assert_equal 1 (n_bytes (of_list [c]))
+  done;
+  true ;;
+
+q Q.(small_list arb_uchar) (fun l ->
+  of_list l = concat empty (List.map of_uchar l));;
+
+q Q.(pair small_nat arb_uchar) (fun (i,c) ->
+  make i c = concat empty (CCList.init i (fun _ -> of_uchar c)));;
diff --git a/tests/core/t_vector.ml b/tests/core/t_vector.ml
new file mode 100644
index 00000000..db981d75
--- /dev/null
+++ b/tests/core/t_vector.ml
@@ -0,0 +1,361 @@
+
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T;;
+open CCVector;;
+
+t @@ fun () -> (create_with ~capacity:200 1 |> capacity) >= 200;;
+t @@ fun () -> return 42 |> to_list = [42];;
+t @@ fun () -> return 42 |> length = 1;;
+t @@ fun () ->
+  let v = create_with ~capacity:10 1 in
+  ensure v 200;
+  capacity v >= 200;;
+t @@ fun () -> let v = create() in push v 0.; push v 1.; push v 2.; 3=length v;;
+t @@ fun () -> let v = create() in push v 1.; push v 2.; push v 3.;
+  6. = (get v 0 +. get v 1 +. get v 2);;
+t @@ fun () -> let v = create() in push v 0; push v 1; push v 2; 3=length v;;
+t @@ fun () -> let v = create() in push v 1; push v 2; push v 3;
+  6 = (get v 0 + get v 1 + get v 2);;
+t @@ fun () -> let v = create() in push v "a"; push v "b"; push v "c"; 3=length v;;
+t @@ fun () -> let v = create() in push v "a"; push v "b"; push v "c";
+  "abc" = String.concat "" (to_list v);;
+
+t @@ fun () ->
+  let v = create() in
+  push v 0.; push v 1.;
+  clear v;
+  push v 0.; push v 1.; push v 7.; push v 10.; push v 12.;
+  truncate v 2;
+  assert_equal 1. (fold (+.) 0. v);
+  clear v;
+  assert_equal 0 (size v);
+  push v 0.; push v 1.; push v 7.; push v 10.; push v 12.;
+  assert_equal (1. +. 7. +. 10. +. 12.) (fold (+.) 0. v);
+  true;;
+
+t @@ fun () ->
+  let v = of_iter Iter.(1 -- 10) in
+  assert_equal 10 (size v);
+  clear v;
+  assert_equal 0 (size v);
+  assert (Iter.is_empty (to_iter v));
+  true;;
+
+t @@ fun () -> let v = create () in push v 1; to_list v = [1];;
+t @@ fun () -> let v = of_list [1;2;3] in push v 4; to_list v = [1;2;3;4];;
+t @@ fun () -> let v = make 1 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4];;
+t @@ fun () -> let v = make 1 0 in resize_with v (fun i -> i) 5; CCList.length (to_list v) = 5;;
+t @@ fun () -> let v = create_with ~capacity:2 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4];;
+t @@ fun () -> let v = make 5 0 in resize_with v (fun i -> i) 5; to_list v = [0;0;0;0;0];;
+t @@ fun () -> let v = make 5 0 in resize_with v (fun i -> i) 6; to_list v = [0;0;0;0;0;5];;
+t @@ fun () -> let v = make 5 0 in
+  try resize_with v (fun i -> i) (-1); false
+  with Invalid_argument _ -> true;;
+t @@ fun () -> let v = make 5 0 in resize_with v (fun i -> i) 5; List.length (to_list v) = 5;;
+
+t @@ fun () -> let v = make 1 0 in resize_with_init v ~init:1 5; to_list v = [0;1;1;1;1];;
+t @@ fun () -> let v = make 1 0 in resize_with_init v ~init:1 5; List.length (to_list v) = 5;;
+t @@ fun () ->
+  let v = create_with ~capacity:2 0 in
+  resize_with_init v ~init:1 5; to_list v = [1;1;1;1;1];;
+t @@ fun () -> let v = make 5 0 in resize_with_init v ~init:1 5; to_list v = [0;0;0;0;0];;
+t @@ fun () -> let v = make 3 0 in resize_with_init v ~init:1 5; to_list v = [0;0;0;1;1];;
+t @@ fun () -> let v = make 5 0 in
+  try resize_with_init v  ~init:1 (-1); false
+  with Invalid_argument _ -> true;;
+t @@ fun () -> let v = make 5 0 in resize_with_init v ~init:1 5; List.length (to_list v) = 5;;
+
+(* test for asymptotic behavior *)
+t @@ fun () -> let v =make 1 0 in
+  for i=0 to 100_000 do resize_with_init v ~init:10 i; done; true;;
+
+t @@ fun () -> let v1 = init 5 (fun i->i) and v2 = init 5 (fun i->i+5) in
+  append v1 v2; to_list v1 = CCList.(0--9);;
+t @@ fun () -> let empty = create () and v2 = init 5 (fun i->i) in
+  append empty v2; to_list empty = CCList.(0--4);;
+t @@ fun () -> let v1 = init 5 (fun i->i) and empty = create () in
+  append v1 empty; to_list v1 = CCList.(0--4);;
+t @@ fun () -> let v = init 3 (fun i->i) in
+  append v v; to_list v = [0; 1; 2; 0; 1; 2];;
+t @@ fun () -> let empty = create () in
+  append empty empty; to_list empty = [];;
+
+t @@ fun () ->
+  let a = of_iter Iter.(1 -- 5) in
+  let b = of_iter Iter.(6 -- 10) in
+  append a b;
+  assert_equal 10 (size a);
+  assert_equal (Iter.to_array Iter.(1 -- 10)) (to_array a);
+  assert_equal (Iter.to_array Iter.(6 -- 10)) (to_array b);
+  true;;
+
+q Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l ->
+    let v1 = of_list l and v2 = of_list l in
+    remove_and_shift v1 9;
+    remove_unordered v2 9;
+    to_list v1 = (to_list v2));;
+q Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l ->
+    let l = List.sort CCInt.compare l in
+    let v = of_list l in
+    remove_and_shift v 3;
+    to_list v = (List.sort CCInt.compare (to_list v)));;
+q Q.(list_of_size (Gen.int_range 10 10) small_int) (fun l ->
+    let l = List.sort CCInt.compare l in
+    let v1 = of_list l and v2 = of_list l in
+    remove_and_shift v1 3;
+    remove_unordered v2 3;
+    to_list v1 = (List.sort CCInt.compare (to_list v2)));;
+
+t @@ fun () -> let v = (1 -- 5) in insert v 3 9; to_list v = [1;2;3;9;4;5];;
+t @@ fun () -> let v = create () in insert v 0 2; to_list v = [2];;
+t @@ fun () -> let v = (1 -- 3) in remove_and_shift v 1; insert v 1 5; to_list v = [1;5;3];;
+t @@ fun () -> let v = (1 -- 3) in remove_and_shift v 0; insert v 2 5; to_list v = [2;3;5];;
+t @@ fun () -> let v = (1 -- 3) in insert v 3 5; to_list v = [1;2;3;5];;
+t @@ fun () ->
+  let v1 = init 5 (fun i->i) and v2 = Array.init 5 (fun i->i+5) in
+  append_array v1 v2; to_list v1 = CCList.(0--9);;
+t @@ fun () -> let empty = create () in
+  append_array empty CCArray.(0--5); to_list empty = CCList.(0--5);;
+t @@ fun () -> let v1 = init 5 (fun i->i) in
+  append_array v1 [| |]; to_list v1 = CCList.(0--4);;
+t @@ fun () -> let empty = create () in
+  append_array empty [| |]; to_list empty = [];;
+
+q Q.(pair (list int)(list int)) (fun (l1,l2) ->
+    let v = of_list l1 in append_list v l2;
+    to_list v = (l1 @ l2)) ;;
+q Q.(pair (list int)(list int)) (fun (l1,l2) ->
+    let v = of_list l1 in append_list v l2;
+    length v = List.length l1 + List.length l2);;
+
+q Q.(pair (list int)(list int)) (fun (l1,l2) ->
+    let v = of_list l1 in append_gen v (Gen.of_list l2);
+    to_list v = (l1 @ l2));;
+q Q.(pair (list int)(list int)) (fun (l1,l2) ->
+    let v = of_list l1 in append_gen v (Gen.of_list l2);
+    length v = List.length l1 + List.length l2);;
+
+let gen x =
+  let small = length in
+  let print = CCOption.map (fun p x -> Q.Print.list p (CCVector.to_list x)) x.Q.print in
+  Q.make ?print ~small Q.Gen.(list x.Q.gen >|= of_list);;
+
+q (Q.pair (gen Q.int) (gen Q.int)) (fun (v1,v2) ->
+    let l1 = to_list v1 in
+    append v1 v2;
+    Iter.to_list (to_iter v1) =
+      Iter.(to_list (append (of_list l1) (to_iter v2)))
+);;
+
+t @@ fun () -> equal (=) (create ()) (create ());;
+t @@ fun () -> equal (=) (return 42) (return 42);;
+t @@ fun () -> not (equal (=) (create ()) (return 42));;
+t @@ fun () -> not (equal (=) (return 42) (create ()));;
+
+q Q.(let g = list_of_size Gen.(0--10) small_int in pair g g) (fun (l1,l2) ->
+  equal (=) (of_list l1) (of_list l2) = (l1=l2));;
+
+q Q.(pair (small_list small_int)(small_list small_int)) (fun (l1,l2) ->
+    let v1 = of_list l1 in
+    let v2 = of_list l2 in
+    equal (=) v1 v2 = (l1=l2));;
+
+q Q.(pair (small_list small_int)(small_list small_int)) (fun (l1,l2) ->
+    let v1 = of_list l1 in
+    let v2 = of_list l2 in
+    compare Stdlib.compare v1 v2 = CCList.compare Stdlib.compare l1 l2) ;;
+
+t @@ fun () -> 1 -- 10 |> top = Some 10;;
+t @@ fun () -> create () |> top = None;;
+t @@ fun () -> 1 -- 10 |> top_exn = 10;;
+
+t @@ fun () -> (let v = of_list [1;2;3] in let v' = copy v in to_list v' = [1;2;3]);;
+t @@ fun () -> create () |> copy |> is_empty;;
+
+t @@ fun () ->
+  let v = of_iter Iter.(1 -- 100) in
+  assert_equal 100 (size v);
+  let v' = copy v in
+  assert_equal 100 (size v');
+  clear v';
+  assert (is_empty v');
+  assert (not (is_empty v));
+  true;;
+
+q Q.(small_list small_int) (fun l ->
+    let v = of_list l in
+    let v' = copy v in
+    equal (=) v v');;
+
+t @@ fun () ->
+  let v = of_iter Iter.(1 -- 10) in
+  truncate v 5;
+  assert_equal [1;2;3;4;5] (to_list v);
+  true ;;
+
+q (gen Q.small_int) (fun v ->
+    let n = size v / 2 in
+    let l = to_list v in
+    let h = Iter.(to_list (take n (of_list l))) in
+    let v' = copy v in
+    truncate v' n;
+    h = to_list v'
+) ;;
+
+q (gen Q.small_int) (fun v ->
+    let v' = copy v in
+    shrink_to_fit v;
+    to_list v = to_list v'
+) ;;
+
+q (gen Q.small_int) (fun v ->
+    let v' = copy v in
+    sort' Stdlib.compare v';
+    let l = to_list v' in
+    List.sort Stdlib.compare l = l
+);;
+
+t @@ fun () -> let v = of_list [1;4;5;3;2;4;1] in
+  uniq_sort Stdlib.compare v; to_list v = [1;2;3;4;5];;
+
+q ~long_factor:10
+  Q.(small_list small_int) (fun l ->
+    let v = of_list l in
+    uniq_sort Stdlib.compare v;
+    to_list v = (CCList.sort_uniq ~cmp:Stdlib.compare l));;
+
+t @@ fun () -> let v = (0--6) in
+  iteri (fun i _ ->  if i = 3 then remove_unordered v i) v; length v = 6;;
+
+t @@ fun () ->
+  let v = create() in push v 1; push v 2; push v 3;
+  to_list (map string_of_int v) = ["1"; "2"; "3"];;
+
+q Q.(pair (fun1 Observable.int small_int) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    to_list (map f v) = List.map f l);;
+
+t @@ fun () ->
+  let v = create() in push v 1; push v 2; push v 3;
+  to_list (mapi (fun i e -> Printf.sprintf "%i %i" i e) v) = ["0 1"; "1 2"; "2 3"];;
+
+q Q.(pair (fun2 Observable.int Observable.int small_int) (small_list small_int))
+    (fun (Q.Fun (_,f),l) ->
+      let v = of_list l in
+      to_list (mapi f v) = List.mapi f l);;
+
+q Q.(pair (fun1 Observable.int small_int) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    map_in_place f v;
+    to_list v = List.map f l);;
+
+t @@ fun () ->
+  let v = 1 -- 10 in filter_in_place (fun x->x<4) v;
+    to_list v = [1;2;3];;
+
+q Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    filter_in_place f v;
+    to_list v = List.filter f l) ;;
+
+t @@ fun () -> filter (fun x-> x mod 2=0) (of_list [1;2;3;4;5]) |> to_list = [2;4];;
+t @@ fun () -> filter (fun x-> x mod 2=0) (1 -- 1_000_000) |> length = 500_000;;
+
+q Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    to_list (filter f v) = List.filter f l);;
+
+t @@ fun () -> fold (+) 0 (of_list [1;2;3;4;5]) = 15;;
+t @@ fun () -> fold (+) 0 (create ()) = 0;;
+
+q Q.(pair (fun2 Observable.int Observable.int small_int) (small_list small_int))
+  (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    fold f 0 v = List.fold_left f 0 l);;
+
+q Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    exists f v = List.exists f l);;
+
+q Q.(pair (fun1 Observable.int bool) (small_list small_int))
+  (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    for_all f v = List.for_all f l);;
+
+q Q.(pair (fun1 Observable.int bool) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    find f v = CCList.find_pred f l);;
+
+q Q.(list small_int) (fun l ->
+    let v = of_list l in
+    let f x = x>30 && x < 35 in
+    find_map (fun x -> if f x then Some x else None) v = find f v);;
+
+q Q.(pair (fun1 Observable.int (option bool)) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    to_list (filter_map f v) = CCList.filter_map f l);;
+
+q Q.(pair (fun1 Observable.int (option small_int)) (small_list small_int)) (fun (Q.Fun (_,f),l) ->
+    let v = of_list l in
+    filter_map_in_place f v;
+    to_list v = CCList.filter_map f l);;
+
+(* check it frees memory properly *)
+t @@ fun () ->
+  let s = "coucou" ^ "lol" in
+  let w = Weak.create 1 in
+  Weak.set w 0 (Some s);
+  let v = of_list ["a"; s] in
+  filter_in_place (fun s -> String.length s <= 1) v;
+  assert_equal 1 (length v);
+  assert_equal "a" (get v 0);
+  Gc.full_major();
+  assert_equal None (Weak.get w 0);
+  true;;
+
+eq ~cmp:(=) ~printer:Q.Print.(list int)
+  [ 11; 12; 21; 22 ] (List.sort CCInt.compare @@
+                      to_list @@ monoid_product (+) (of_list [10; 20]) (of_list [1; 2]));;
+eq ~cmp:(=) ~printer:Q.Print.(list int)
+  [ 11; 12; 13; 14 ] (List.sort CCInt.compare @@
+                      to_list @@ monoid_product (+) (of_list [10]) (of_list [1; 2; 3; 4]));;
+
+q Q.(small_list small_int) (fun l ->
+    let v = of_list l in
+    rev_in_place v;
+    to_list v = List.rev l);;
+
+t @@ fun () -> rev (of_list [1;2;3;4]) |> to_list = [4;3;2;1];;
+t @@ fun () -> rev (of_list [1;2;3;4;5]) |> to_list = [5;4;3;2;1];;
+t @@ fun () -> rev (create ()) |> to_list = [];;
+
+q Q.(small_list small_int) (fun l ->
+    let v = of_list l in
+    to_list (rev v) = List.rev l);;
+
+t @@ fun () -> let v = of_list [1;2;3] in (fun f->rev_iter f v) |> Iter.to_list = [3;2;1];;
+
+q Q.(list int) (fun l ->
+    let v = of_list l in
+    (fun f->rev_iter f v) |> Iter.to_list = List.rev l);;
+
+t @@ fun () -> of_iter Iter.(1 -- 10) |> to_list = CCList.(1 -- 10);;
+
+q Q.(list int) (fun l ->
+  let v= of_list l in v |> to_iter_rev |> Iter.to_rev_list = l);;
+
+t @@ fun () -> slice_iter (of_list [0;1;2;3;4]) 1 3 |> CCList.of_iter = [1;2;3];;
+t @@ fun () -> slice_iter (of_list [0;1;2;3;4]) 1 4 |> CCList.of_iter = [1;2;3;4];;
+t @@ fun () -> slice_iter (of_list [0;1;2;3;4]) 0 5 |> CCList.of_iter = [0;1;2;3;4];;
+t @@ fun () -> (1 -- 4) |> to_list = [1;2;3;4];;
+t @@ fun () -> (4 -- 1) |> to_list = [4;3;2;1];;
+t @@ fun () -> (0 -- 0) |> to_list = [0];;
+
+q Q.(pair small_int small_int) (fun (a,b) ->
+  (a -- b) |> to_list = CCList.(a -- b));;
+
+q Q.(pair small_int small_int) (fun (a,b) ->
+  (a --^ b) |> to_list = CCList.(a --^ b));;
+
+t @@ fun () -> of_list CCList.(1--300_000) |> to_list = CCList.(1--300_000);;
+t @@ fun () -> let v = (1--10) in to_list v = Gen.to_list (to_gen v);;