From 656565c1957da549ddec6498e640fe9c8e58eb4f Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Mon, 22 Aug 2016 10:15:37 +0200
Subject: [PATCH 01/16] add gh-pages doc generation to makefile

---
 Makefile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Makefile b/Makefile
index ed28398b..00dd73da 100644
--- a/Makefile
+++ b/Makefile
@@ -55,6 +55,13 @@ examples: all
 push_doc: doc
 	rsync -tavu containers.docdir/* cedeela.fr:~/simon/root/software/containers/
 
+push_doc_gh: doc
+	git checkout gh-pages && \
+	  rm -rf dev/ && \
+	  mkdir -p dev && \
+	  cp -r containers.docdir/* dev/ && \
+	  git add --all dev
+
 DONTTEST=myocamlbuild.ml setup.ml $(wildcard src/**/*.cppo.*)
 QTESTABLE=$(filter-out $(DONTTEST), \
 	$(wildcard src/core/*.ml) \

From 8cd06599aea41e1caa7c291d7a07fec3ba108825 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Mon, 22 Aug 2016 10:21:19 +0200
Subject: [PATCH 02/16] update readme

---
 README.adoc | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/README.adoc b/README.adoc
index b0180351..5028ce5a 100644
--- a/README.adoc
+++ b/README.adoc
@@ -3,7 +3,7 @@
 :source-highlighter: pygments
 
 What is _containers_? (take a look at the link:TUTORIAL.adoc[tutorial]!
-or the http://cedeela.fr/~simon/software/containers[documentation])
+or the http://cedeela.fr/~simon/software/containers[current documentation])
 In `containers` and `containers.data`, all modules abide by
 _pay for what you use_: only modules that are used are linked (there are no
 cross-module dependencies).
@@ -230,6 +230,18 @@ The library has moved to https://github.com/c-cube/containers-misc .
 `containers.lwt` has moved to https://github.com/c-cube/containers-lwt .
 
 [[build]]
+
+== Documentation
+
+In general, see http://c-cube.github.io/ocaml-containers/ or 
+http://cedeela.fr/~simon/software/containers
+
+by version:
+
+- http://c-cube.github.io/ocaml-containers/dev/[dev branch]
+- http://c-cube.github.io/ocaml-containers/0.17/[0.17]
+- http://c-cube.github.io/ocaml-containers/0.19/[0.19]
+
 == Build
 
 You will need OCaml `>=` 4.00.0.
@@ -270,7 +282,3 @@ A few guidelines:
 - add tests if possible (using `qtest`).
 
 Powered by image:http://oasis.forge.ocamlcore.org/oasis-badge.png[alt="OASIS", style="border: none;", link="http://oasis.forge.ocamlcore.org/"]
-
-== Documentation by version
-
-- http://c-cube.github.io/ocaml-containers/0.17/[0.17]

From b249adf86f1e84a23bbfb7af9cce4f25ccf8f147 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 18 Sep 2016 10:33:35 +0200
Subject: [PATCH 03/16] add `CCInt.{print_binary,to_string_binary}` + tests
 (thanks @gsg)

---
 AUTHORS.adoc       |  1 +
 src/core/CCInt.ml  | 44 ++++++++++++++++++++++++++++++++++++++++++++
 src/core/CCInt.mli |  7 +++++++
 3 files changed, 52 insertions(+)

diff --git a/AUTHORS.adoc b/AUTHORS.adoc
index be70282a..478c46aa 100644
--- a/AUTHORS.adoc
+++ b/AUTHORS.adoc
@@ -14,3 +14,4 @@
 - JP Rodi
 - octachron (Florian Angeletti)
 - Johannes Kloos
+- Geoff Gole (@gsg)
diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index ba1d82a2..16012426 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -48,12 +48,56 @@ let random_range i j st = i + random (j-i) st
 let pp buf = Printf.bprintf buf "%d"
 let print fmt = Format.pp_print_int fmt
 
+let most_significant_bit =
+  (-1) lxor ((-1) lsr 1)
+
 let to_string = string_of_int
 
 let of_string s =
   try Some (int_of_string s)
   with _ -> None
 
+type output = char -> unit
+
+(* abstract printer *)
+let to_binary_gen (out:output) n =
+  let n = if n<0 then (out '-'; -n) else n in
+  out '0'; out 'b';
+  let rec loop started bit n =
+    if bit = 0 then (
+      if not started then out '0'
+    ) else (
+      let b = n land bit in
+      if b = 0 then (
+        if started then out '0';
+        loop started (bit lsr 1) n
+      ) else (
+        out '1';
+        loop true (bit lsr 1) n
+      )
+    )
+  in
+  loop false most_significant_bit n
+
+let print_binary out n =
+  to_binary_gen (Format.pp_print_char out) n
+
+let to_string_binary n =
+  let buf = Buffer.create 16 in
+  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))
+*)
+
 module Infix = struct
   let (=) = Pervasives.(=)
   let (<>) = Pervasives.(<>)
diff --git a/src/core/CCInt.mli b/src/core/CCInt.mli
index adc77339..c6b116d9 100644
--- a/src/core/CCInt.mli
+++ b/src/core/CCInt.mli
@@ -40,6 +40,13 @@ val to_string : t -> string
 val of_string : string -> t option
 (** @since 0.13 *)
 
+val print_binary : t formatter
+(** prints as "0b00101010".
+    @since NEXT_RELEASE *)
+
+val to_string_binary : t -> string
+(** @since NEXT_RELEASE *)
+
 val min : t -> t -> t
 (** @since 0.17 *)
 

From 7a823b16d8b39b3f466b35eff10d1cf4576e440f Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 18 Sep 2016 20:31:53 +0200
Subject: [PATCH 04/16] fix `CCString.*_ascii`; add
 `CCChar.{upper,lower}case_ascii`

---
 src/core/CCChar.ml        | 10 ++++++++++
 src/core/CCChar.mli       |  8 ++++++++
 src/core/CCString.cppo.ml | 18 ++++++++++++++----
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/src/core/CCChar.ml b/src/core/CCChar.ml
index a1622930..460d2eed 100644
--- a/src/core/CCChar.ml
+++ b/src/core/CCChar.ml
@@ -11,3 +11,13 @@ let compare = Char.compare
 
 let pp = Buffer.add_char
 let print = Format.pp_print_char
+
+let lowercase_ascii c =
+  if c >= 'A' && c <= 'Z'
+  then Char.unsafe_chr (Char. code c + 32)
+  else c
+
+let uppercase_ascii c =
+  if c >= 'a' && c <= 'z'
+  then Char.unsafe_chr (Char.code c - 32)
+  else c
diff --git a/src/core/CCChar.mli b/src/core/CCChar.mli
index 1ca8dcd3..345049b2 100644
--- a/src/core/CCChar.mli
+++ b/src/core/CCChar.mli
@@ -9,5 +9,13 @@ type t = char
 val equal : t -> t -> bool
 val compare : t -> t -> int
 
+val lowercase_ascii : t -> t
+(** See {!Char}
+    @since NEXT_RELEASE *)
+
+val uppercase_ascii : t -> t
+(** See {!Char}
+    @since NEXT_RELEASE *)
+
 val pp : Buffer.t -> t -> unit
 val print : Format.formatter -> t -> unit
diff --git a/src/core/CCString.cppo.ml b/src/core/CCString.cppo.ml
index d29da1e6..61fa8240 100644
--- a/src/core/CCString.cppo.ml
+++ b/src/core/CCString.cppo.ml
@@ -651,10 +651,20 @@ let lowercase_ascii = String.lowercase_ascii
 
 #else
 
-let capitalize_ascii = String.capitalize
-let uncapitalize_ascii = String.uncapitalize
-let uppercase_ascii = String.uppercase
-let lowercase_ascii = String.lowercase
+let capitalize_ascii s =
+  mapi
+    (fun i c -> if i=0 then CCChar.uppercase_ascii c else c)
+    s
+    
+
+let uncapitalize_ascii s =
+  mapi
+    (fun i c -> if i=0 then CCChar.lowercase_ascii c else c)
+    s
+
+let uppercase_ascii = map CCChar.uppercase_ascii
+
+let lowercase_ascii = map CCChar.lowercase_ascii
 
 #endif
 

From 3e50420ce8eb83d90a1e9454984dcf847a68f441 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 25 Sep 2016 19:34:05 +0200
Subject: [PATCH 05/16] add `CCList.{head_opt,last_opt}`

---
 src/core/CCList.ml  | 18 ++++++++++++++++++
 src/core/CCList.mli |  8 ++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index 92c2747d..17a29a04 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -569,6 +569,24 @@ let last n l =
   let len = List.length l in
   if len < n then l else drop (len-n) l
 
+let head_opt = function
+  | [] -> None
+  | x::_ -> Some x
+
+let rec last_opt = function
+  | [] -> None
+  | [x] -> Some x
+  | _ :: tail -> last_opt tail
+
+(*$= & ~printer:Q.Print.(option int)
+  (Some 1) (head_opt [1;2;3])
+  (Some 1) (head_opt [1])
+  None (head_opt [])
+  (Some 3) (last_opt [1;2;3])
+  (Some 1) (last_opt [1])
+  None (last_opt [])
+*)
+
 let rec find_pred p l = match l with
   | [] -> None
   | x :: _ when p x -> Some x
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index a3a35b26..3331b9a7 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -134,6 +134,14 @@ val last : int -> 'a t -> 'a t
 (** [last n l] takes the last [n] elements of [l] (or less if
     [l] doesn't have that many elements *)
 
+val head_opt : 'a t -> 'a option
+(** First element.
+    @since NEXT_RELEASE *)
+
+val last_opt : 'a t -> 'a option
+(** Last element.
+    @since NEXT_RELEASE *)
+
 val find_pred : ('a -> bool) -> 'a t -> 'a option
 (** [find_pred p l] finds the first element of [l] that satisfies [p],
     or returns [None] if no element satisfies [p]

From e4c6752b6b4b60a5b190bae3e3ec439de6a98eab Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 25 Sep 2016 19:38:03 +0200
Subject: [PATCH 06/16] add `CCVector.append_gen`

---
 src/core/CCVector.ml  | 14 ++++++++++++++
 src/core/CCVector.mli |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 40296609..240774fe 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -226,6 +226,20 @@ let append_list a b = match b with
     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
diff --git a/src/core/CCVector.mli b/src/core/CCVector.mli
index e3a329cd..11dfdee6 100644
--- a/src/core/CCVector.mli
+++ b/src/core/CCVector.mli
@@ -84,6 +84,10 @@ val append_list : ('a, rw) t -> 'a list -> unit
 (** Append content of list
     @since 0.14 *)
 
+val append_gen : ('a, rw) t -> 'a gen -> unit
+(** Append content of generator
+    @since NEXT_RELEASE *)
+
 val equal : 'a equal -> ('a,_) t equal
 
 val compare : 'a ord -> ('a,_) t ord

From 103963dc4576b9e33d69a4cd3e58350ff14421ad Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 25 Sep 2016 19:39:02 +0200
Subject: [PATCH 07/16] style

---
 src/core/CCFloat.mli | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/core/CCFloat.mli b/src/core/CCFloat.mli
index 5b47483b..a2e423f2 100644
--- a/src/core/CCFloat.mli
+++ b/src/core/CCFloat.mli
@@ -19,7 +19,7 @@ val min_value : t
 
 val max_finite_value : t
 
-val epsilon : float
+val epsilon : t
 
 val is_nan : t -> bool
 
@@ -39,7 +39,7 @@ val max : t -> t -> t
 
 val equal : t -> t -> bool
 
-val compare : float -> float -> int
+val compare : t -> t -> int
 
 type 'a printer = Buffer.t -> 'a -> unit
 type 'a formatter = Format.formatter -> 'a -> unit
@@ -54,7 +54,7 @@ val random : t -> t random_gen
 val random_small : t random_gen
 val random_range : t -> t -> t random_gen
 
-val fsign : t -> float
+val fsign : t -> t
 (** [fsign x] is one of [-1., -0., +0., +1.], or [nan] if [x] is NaN.
     @since 0.7 *)
 
@@ -75,7 +75,7 @@ val of_string : string -> t
 val equal_precision : epsilon:t -> t -> t -> bool
 (** Equality with allowed error up to a non negative epsilon value *)
 
-val classify : float -> fpclass
+val classify : t -> fpclass
 
 (** {2 Infix Operators}
 

From d7e8cb24fd65b81370c5b0eaa3f8778a3d0ec119 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 25 Sep 2016 19:43:21 +0200
Subject: [PATCH 08/16] add `CCFloat.round`

---
 src/core/CCFloat.ml  | 11 +++++++++++
 src/core/CCFloat.mli |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/src/core/CCFloat.ml b/src/core/CCFloat.ml
index 2fbbe071..0d73342d 100644
--- a/src/core/CCFloat.ml
+++ b/src/core/CCFloat.ml
@@ -60,6 +60,17 @@ let sign_exn (a:float) =
   if is_nan a then raise (TrapNaN "sign_exn")
   else compare a 0.
 
+let round x =
+  let low = floor x in
+  let high = ceil x in
+  if x-.low > high-.x then high else low
+
+(*$=
+  2. (round 1.6)
+  1. (round 1.4)
+  0. (round 0.)
+*)
+
 let to_int (a:float) = Pervasives.int_of_float a
 let of_int (a:int) = Pervasives.float_of_int a
 
diff --git a/src/core/CCFloat.mli b/src/core/CCFloat.mli
index a2e423f2..538d2068 100644
--- a/src/core/CCFloat.mli
+++ b/src/core/CCFloat.mli
@@ -58,6 +58,10 @@ val fsign : t -> t
 (** [fsign x] is one of [-1., -0., +0., +1.], or [nan] if [x] is NaN.
     @since 0.7 *)
 
+val round : t -> t
+(** [round f] returns the closest integer value, either above or below
+    @since NEXT_RELEASE *)
+
 exception TrapNaN of string
 val sign_exn : t -> int
 (** [sign_exn x] will return the sign of [x] as [1, 0] or [-1], or raise an

From d4d22b14889d258d8d979c8e0042b0357641c971 Mon Sep 17 00:00:00 2001
From: Roma Sokolov <sokolov.r.v@gmail.com>
Date: Tue, 4 Oct 2016 14:27:34 +0300
Subject: [PATCH 09/16] Fixes map_or

~default arg for `map_or`, as well as function, should not depend on the type of error case.
---
 src/core/CCResult.mli | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/CCResult.mli b/src/core/CCResult.mli
index 9a1dedc2..fb764167 100644
--- a/src/core/CCResult.mli
+++ b/src/core/CCResult.mli
@@ -67,7 +67,7 @@ val get_exn : ('a, _) t -> 'a
 val get_or : ('a, _) t -> default:'a -> 'a
 (** [get_or e ~default] returns [x] if [e = Ok x], [default] otherwise *)
 
-val map_or : ('a -> 'b) ->  ('a, 'b) t -> default:'b -> 'b
+val map_or : ('a -> 'b) ->  ('a, 'c) t -> default:'b -> 'b
 (** [map_or f e ~default] returns [f x] if [e = Ok x], [default] otherwise *)
 
 val catch : ('a, 'err) t -> ok:('a -> 'b) -> err:('err -> 'b) -> 'b

From f0381ae0d928d98900938bc9e378d2636585fc84 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Tue, 4 Oct 2016 13:35:46 +0200
Subject: [PATCH 10/16] update `authors`

---
 AUTHORS.adoc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/AUTHORS.adoc b/AUTHORS.adoc
index 478c46aa..de89cd30 100644
--- a/AUTHORS.adoc
+++ b/AUTHORS.adoc
@@ -12,6 +12,7 @@
 - Emmanuel Surleau (emm)
 - Guillaume Bury (guigui)
 - JP Rodi
-- octachron (Florian Angeletti)
+- Florian Angeletti (@octachron)
 - Johannes Kloos
 - Geoff Gole (@gsg)
+- Roma Sokolov (@little-arhat)

From a99720945b2a4627f12d6248b2d5b2da13dfaf5f Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Thu, 13 Oct 2016 10:01:21 +0200
Subject: [PATCH 11/16] add `CCArray.rev`

---
 src/core/CCArray.ml  | 15 +++++++++++++++
 src/core/CCArray.mli |  4 ++++
 2 files changed, 19 insertions(+)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index a7230a77..7c38eb45 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -350,6 +350,21 @@ let reverse_in_place a =
     a = [| 6;5;4;3;2;1 |]
 *)
 
+let rev a =
+  let b = Array.copy a in
+  reverse_in_place b;
+  b
+
+(*$Q
+  Q.(array small_int) (fun a -> rev (rev a) = a)
+*)
+
+(*$T
+  rev [| 1; 2; 3 |] = [| 3; 2; 1 |]
+  rev [| 1; 2; |] = [| 2; 1 |]
+  rev [| |] = [| |]
+  *)
+
 let find f a =
   _find (fun _ -> f ) a 0 (Array.length a)
 
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index eb6b9d29..fd7eb5bb 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -143,6 +143,10 @@ include S with type 'a t := 'a t
 
 val map : ('a -> 'b) -> 'a t -> 'b t
 
+val rev : 'a t -> 'a t
+(** Copy + reverse in place
+    @since NEXT_RELEASE *)
+
 val filter : ('a -> bool) -> 'a t -> 'a t
 (** Filter elements out of the array. Only the elements satisfying
     the given predicate will be kept. *)

From 53030c4c29239d3b422cc66dbd296573ef1d0a98 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Thu, 13 Oct 2016 10:04:23 +0200
Subject: [PATCH 12/16] more general types for `CCArray.{for_all2,exists2}`

---
 src/core/CCArray.ml  | 10 ++++++----
 src/core/CCArray.mli | 10 ++++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 7c38eb45..4890a9a3 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -94,15 +94,17 @@ module type S = sig
 
   val for_all : ('a -> bool) -> 'a t -> bool
 
-  val for_all2 : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+  val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Forall on pairs of arrays.
-      @raise Invalid_argument if they have distinct lengths *)
+      @raise Invalid_argument if they have distinct lengths
+      allow different types @since NEXT_RELEASE *)
 
   val exists : ('a -> bool) -> 'a t -> bool
 
-  val exists2 : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+  val exists2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Exists on pairs of arrays.
-      @raise Invalid_argument if they have distinct lengths *)
+      @raise Invalid_argument if they have distinct lengths
+      allow different types @since NEXT_RELEASE *)
 
   val shuffle : 'a t -> unit
   (** shuffle randomly the array, in place *)
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index fd7eb5bb..6b417c51 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -96,15 +96,17 @@ module type S = sig
 
   val for_all : ('a -> bool) -> 'a t -> bool
 
-  val for_all2 : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+  val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Forall on pairs of arrays.
-      @raise Invalid_argument if they have distinct lengths *)
+      @raise Invalid_argument if they have distinct lengths
+      allow different types @since NEXT_RELEASE *)
 
   val exists : ('a -> bool) -> 'a t -> bool
 
-  val exists2 : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+  val exists2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Exists on pairs of arrays.
-      @raise Invalid_argument if they have distinct lengths *)
+      @raise Invalid_argument if they have distinct lengths
+      allow different types @since NEXT_RELEASE *)
 
   val shuffle : 'a t -> unit
   (** Shuffle randomly the array, in place *)

From fed7dd41e063454883cd6eaee83bf894de00796a Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Thu, 13 Oct 2016 10:04:58 +0200
Subject: [PATCH 13/16] add functions in `CCArray`: fold2,iter2,map2

---
 src/core/CCArray.ml  | 52 ++++++++++++++++++++++++++++++++++++++++----
 src/core/CCArray.mli | 15 +++++++++++++
 2 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 4890a9a3..6daf0f08 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -106,8 +106,18 @@ module type S = sig
       @raise Invalid_argument if they have distinct lengths
       allow different types @since NEXT_RELEASE *)
 
+  val fold2 : ('acc -> 'a -> 'b -> 'acc) -> 'acc -> 'a t -> 'b t -> 'acc
+  (** Fold on two arrays stepwise.
+      @raise Invalid_argument if they have distinct lengths
+      @since NEXT_RELEASE *)
+
+  val iter2 : ('a -> 'b -> unit) -> 'a t -> 'b t -> unit
+  (** Iterate on two arrays stepwise.
+      @raise Invalid_argument if they have distinct lengths
+      @since NEXT_RELEASE *)
+
   val shuffle : 'a t -> unit
-  (** shuffle randomly the array, in place *)
+  (** Shuffle randomly the array, in place *)
 
   val shuffle_with : Random.State.t -> 'a t -> unit
   (** Like shuffle but using a specialized random state *)
@@ -124,15 +134,15 @@ module type S = sig
 
   val pp: ?sep:string -> (Buffer.t -> 'a -> unit) ->
           Buffer.t -> 'a t -> unit
-  (** print an array of items with printing function *)
+  (** Print an array of items with printing function *)
 
   val pp_i: ?sep:string -> (Buffer.t -> int -> 'a -> unit) ->
             Buffer.t -> 'a t -> unit
-  (** print an array, giving the printing function both index and item *)
+  (** Print an array, giving the printing function both index and item *)
 
   val print : ?sep:string -> (Format.formatter -> 'a -> unit) ->
               Format.formatter -> 'a t -> unit
-  (** print an array of items with printing function *)
+  (** Print an array of items with printing function *)
 end
 
 (** {2 General Implementation}
@@ -293,6 +303,10 @@ let empty = [| |]
 
 let map = Array.map
 
+let map2 f a b =
+  if Array.length a <> Array.length b then invalid_arg "map2";
+  Array.init (Array.length a) (fun i -> f (Array.unsafe_get a i) (Array.unsafe_get b i))
+
 let length = Array.length
 
 let get = Array.get
@@ -472,6 +486,28 @@ let for_all2 p a b =
 let exists2 p a b =
   _exists2 p a b 0 0 ~len:(min (Array.length a) (Array.length b))
 
+let _iter2 f a b i j ~len =
+  for o = 0 to len-1 do
+    f (Array.get a (i+o)) (Array.get b (j+o))
+  done
+
+let _fold2 f acc a b i j ~len =
+  let rec aux acc o =
+    if o=len then acc
+    else
+      let acc = f acc (Array.get a (i+o)) (Array.get b (j+o)) in
+      aux acc (o+1)
+  in
+  aux acc 0
+
+let iter2 f a b =
+  if length a <> length b then invalid_arg "iter2";
+  _iter2 f a b 0 0 ~len:(Array.length a)
+
+let fold2 f acc a b =
+  if length a <> length b then invalid_arg "fold2";
+  _fold2 f acc a b 0 0 ~len:(Array.length a)
+
 let (--) i j =
   if i<=j
   then
@@ -675,6 +711,14 @@ module Sub = struct
   Sub.exists2 (=) (Sub.make [| 1;2;3;4 |] 1 ~len:2) (Sub.make [| 0;1;3;4 |] 1 ~len:3)
   *)
 
+  let iter2 f a b =
+    if length a <> length b then invalid_arg "iter2";
+    _iter2 f a.arr b.arr a.i b.i ~len:(length a)
+
+  let fold2 f acc a b =
+    if length a <> length b then invalid_arg "fold2";
+    _fold2 f acc a.arr b.arr a.i b.i ~len:(length a)
+
   let shuffle a =
     _shuffle Random.int a.arr a.i a.j
 
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 6b417c51..24be5897 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -108,6 +108,16 @@ module type S = sig
       @raise Invalid_argument if they have distinct lengths
       allow different types @since NEXT_RELEASE *)
 
+  val fold2 : ('acc -> 'a -> 'b -> 'acc) -> 'acc -> 'a t -> 'b t -> 'acc
+  (** Fold on two arrays stepwise.
+      @raise Invalid_argument if they have distinct lengths
+      @since NEXT_RELEASE *)
+
+  val iter2 : ('a -> 'b -> unit) -> 'a t -> 'b t -> unit
+  (** Iterate on two arrays stepwise.
+      @raise Invalid_argument if they have distinct lengths
+      @since NEXT_RELEASE *)
+
   val shuffle : 'a t -> unit
   (** Shuffle randomly the array, in place *)
 
@@ -145,6 +155,11 @@ include S with type 'a t := 'a t
 
 val map : ('a -> 'b) -> 'a t -> 'b t
 
+val map2 : ('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
+(** Map on two arrays stepwise.
+      @raise Invalid_argument if they have distinct lengths
+      @since NEXT_RELEASE *)
+
 val rev : 'a t -> 'a t
 (** Copy + reverse in place
     @since NEXT_RELEASE *)

From 59a463a882e9c09a56e5a6bed6ee0bae1fcd383b Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Fri, 14 Oct 2016 11:23:45 +0200
Subject: [PATCH 14/16] small fix + test

---
 src/core/CCArray.ml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 6daf0f08..6ee5e850 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -162,7 +162,7 @@ let _reverse_in_place a i ~len =
     done
 
 let rec _equal eq a1 i1 j1 a2 i2 j2 =
-  if i1 = j1 || i2 = j2
+  if i1 = j1
   then (assert (i1=j1 && i2=j2); true)
   else
     eq a1.(i1) a2.(i2) && _equal eq a1 (i1+1) j1 a2 (i2+2) j2
@@ -548,6 +548,11 @@ let equal eq a b =
   &&
   _equal eq a 0 (Array.length a) b 0 (Array.length b)
 
+(*$Q
+  Q.(pair (array small_int)(array small_int)) (fun (a,b) -> \
+    equal (=) a b = equal (=) b a)
+*)
+
 let compare cmp a b =
   _compare cmp a 0 (Array.length a) b 0 (Array.length b)
 

From 81ca239ccc201de313f5ee5b69086af574f8e083 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Fri, 14 Oct 2016 11:28:44 +0200
Subject: [PATCH 15/16] bugfix in CCArray.equal

---
 src/core/CCArray.ml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 6ee5e850..9b179414 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -165,7 +165,7 @@ let rec _equal eq a1 i1 j1 a2 i2 j2 =
   if i1 = j1
   then (assert (i1=j1 && i2=j2); true)
   else
-    eq a1.(i1) a2.(i2) && _equal eq a1 (i1+1) j1 a2 (i2+2) j2
+    eq a1.(i1) a2.(i2) && _equal eq a1 (i1+1) j1 a2 (i2+1) j2
 
 let rec _compare cmp a1 i1 j1 a2 i2 j2 =
   if i1 = j1
@@ -553,6 +553,10 @@ let equal eq a b =
     equal (=) a b = equal (=) b a)
 *)
 
+(*$T
+  equal (=) [|1|] [|1|]
+*)
+
 let compare cmp a b =
   _compare cmp a 0 (Array.length a) b 0 (Array.length b)
 

From bc7967054f5e2d28ec29f277284d4a017d58bdcb Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Fri, 14 Oct 2016 11:33:53 +0200
Subject: [PATCH 16/16] prepare for 0.20

---
 CHANGELOG.adoc        | 14 ++++++++++++++
 _oasis                |  4 ++--
 src/core/CCArray.ml   |  8 ++++----
 src/core/CCArray.mli  | 12 ++++++------
 src/core/CCChar.mli   |  4 ++--
 src/core/CCFloat.mli  |  2 +-
 src/core/CCInt.mli    |  4 ++--
 src/core/CCList.mli   |  4 ++--
 src/core/CCVector.mli |  2 +-
 9 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 2f2ab89f..506ae9df 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -1,5 +1,19 @@
 = Changelog
 
+== 0.20
+
+- bugfix in `CCArray.equal`
+- fix `CCString.*_ascii`; add `CCChar.{upper,lower}case_ascii`
+
+- add functions in `CCArray`: fold2,iter2,map2
+- add `CCArray.rev`
+- add `CCFloat.round`
+- add `CCVector.append_gen`
+- add `CCList.{head_opt,last_opt}`
+- add `CCInt.{print_binary,to_string_binary}` + tests (thanks @gsg)
+- more general types for `CCArray.{for_all2,exists2}`
+- more general type for `CCResult.map_or`
+
 == 0.19
 
 - add regression test for #75
diff --git a/_oasis b/_oasis
index 6a4e3702..2ea5ba5d 100644
--- a/_oasis
+++ b/_oasis
@@ -1,6 +1,6 @@
 OASISFormat: 0.4
 Name:        containers
-Version:     0.19
+Version:     0.20
 Homepage:    https://github.com/c-cube/ocaml-containers
 Authors:     Simon Cruanes
 License:     BSD-2-clause
@@ -179,7 +179,7 @@ Executable run_qtest
                     containers.io, containers.advanced, containers.sexp,
                     containers.bigarray, containers.unix, containers.thread,
                     containers.data,
-                    sequence, gen, unix, oUnit, qcheck 
+                    sequence, gen, unix, oUnit, qcheck
 
 Test all
   Command:      ./run_qtest.native
diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 9b179414..cc7b622f 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -97,24 +97,24 @@ module type S = sig
   val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Forall on pairs of arrays.
       @raise Invalid_argument if they have distinct lengths
-      allow different types @since NEXT_RELEASE *)
+      allow different types @since 0.20 *)
 
   val exists : ('a -> bool) -> 'a t -> bool
 
   val exists2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Exists on pairs of arrays.
       @raise Invalid_argument if they have distinct lengths
-      allow different types @since NEXT_RELEASE *)
+      allow different types @since 0.20 *)
 
   val fold2 : ('acc -> 'a -> 'b -> 'acc) -> 'acc -> 'a t -> 'b t -> 'acc
   (** Fold on two arrays stepwise.
       @raise Invalid_argument if they have distinct lengths
-      @since NEXT_RELEASE *)
+      @since 0.20 *)
 
   val iter2 : ('a -> 'b -> unit) -> 'a t -> 'b t -> unit
   (** Iterate on two arrays stepwise.
       @raise Invalid_argument if they have distinct lengths
-      @since NEXT_RELEASE *)
+      @since 0.20 *)
 
   val shuffle : 'a t -> unit
   (** Shuffle randomly the array, in place *)
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 24be5897..8206d2cb 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -99,24 +99,24 @@ module type S = sig
   val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Forall on pairs of arrays.
       @raise Invalid_argument if they have distinct lengths
-      allow different types @since NEXT_RELEASE *)
+      allow different types @since 0.20 *)
 
   val exists : ('a -> bool) -> 'a t -> bool
 
   val exists2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool
   (** Exists on pairs of arrays.
       @raise Invalid_argument if they have distinct lengths
-      allow different types @since NEXT_RELEASE *)
+      allow different types @since 0.20 *)
 
   val fold2 : ('acc -> 'a -> 'b -> 'acc) -> 'acc -> 'a t -> 'b t -> 'acc
   (** Fold on two arrays stepwise.
       @raise Invalid_argument if they have distinct lengths
-      @since NEXT_RELEASE *)
+      @since 0.20 *)
 
   val iter2 : ('a -> 'b -> unit) -> 'a t -> 'b t -> unit
   (** Iterate on two arrays stepwise.
       @raise Invalid_argument if they have distinct lengths
-      @since NEXT_RELEASE *)
+      @since 0.20 *)
 
   val shuffle : 'a t -> unit
   (** Shuffle randomly the array, in place *)
@@ -158,11 +158,11 @@ val map : ('a -> 'b) -> 'a t -> 'b t
 val map2 : ('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
 (** Map on two arrays stepwise.
       @raise Invalid_argument if they have distinct lengths
-      @since NEXT_RELEASE *)
+      @since 0.20 *)
 
 val rev : 'a t -> 'a t
 (** Copy + reverse in place
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val filter : ('a -> bool) -> 'a t -> 'a t
 (** Filter elements out of the array. Only the elements satisfying
diff --git a/src/core/CCChar.mli b/src/core/CCChar.mli
index 345049b2..748ab659 100644
--- a/src/core/CCChar.mli
+++ b/src/core/CCChar.mli
@@ -11,11 +11,11 @@ val compare : t -> t -> int
 
 val lowercase_ascii : t -> t
 (** See {!Char}
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val uppercase_ascii : t -> t
 (** See {!Char}
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val pp : Buffer.t -> t -> unit
 val print : Format.formatter -> t -> unit
diff --git a/src/core/CCFloat.mli b/src/core/CCFloat.mli
index 538d2068..766027ac 100644
--- a/src/core/CCFloat.mli
+++ b/src/core/CCFloat.mli
@@ -60,7 +60,7 @@ val fsign : t -> t
 
 val round : t -> t
 (** [round f] returns the closest integer value, either above or below
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 exception TrapNaN of string
 val sign_exn : t -> int
diff --git a/src/core/CCInt.mli b/src/core/CCInt.mli
index c6b116d9..7657a315 100644
--- a/src/core/CCInt.mli
+++ b/src/core/CCInt.mli
@@ -42,10 +42,10 @@ val of_string : string -> t option
 
 val print_binary : t formatter
 (** prints as "0b00101010".
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val to_string_binary : t -> string
-(** @since NEXT_RELEASE *)
+(** @since 0.20 *)
 
 val min : t -> t -> t
 (** @since 0.17 *)
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index 3331b9a7..93df4694 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -136,11 +136,11 @@ val last : int -> 'a t -> 'a t
 
 val head_opt : 'a t -> 'a option
 (** First element.
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val last_opt : 'a t -> 'a option
 (** Last element.
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val find_pred : ('a -> bool) -> 'a t -> 'a option
 (** [find_pred p l] finds the first element of [l] that satisfies [p],
diff --git a/src/core/CCVector.mli b/src/core/CCVector.mli
index 11dfdee6..ad47b070 100644
--- a/src/core/CCVector.mli
+++ b/src/core/CCVector.mli
@@ -86,7 +86,7 @@ val append_list : ('a, rw) t -> 'a list -> unit
 
 val append_gen : ('a, rw) t -> 'a gen -> unit
 (** Append content of generator
-    @since NEXT_RELEASE *)
+    @since 0.20 *)
 
 val equal : 'a equal -> ('a,_) t equal