From 72cb078fa37c88e92e1aaeb33d12ba6541350a7e Mon Sep 17 00:00:00 2001
From: Jacques-Pascal Deplaix <jp.deplaix@gmail.com>
Date: Mon, 6 Nov 2017 19:44:19 +0100
Subject: [PATCH] Avoid unsafe polymorphic functions and operators

---
 _oasis                     | 11 ++++++----
 src/core/CCBool.ml         |  2 +-
 src/core/CCChar.ml         | 16 ++++++--------
 src/core/CCEqual.ml        | 10 ++++-----
 src/core/CCFloat.ml        | 20 ++++++++---------
 src/core/CCInt.ml          |  2 +-
 src/core/CCInt64.ml        |  2 +-
 src/core/CCList.ml         | 44 +++++++++++++++++++-------------------
 src/core/CCList.mli        | 42 ++++++++++++++++++------------------
 src/core/CCListLabels.ml   | 44 +++++++++++++++++++-------------------
 src/core/CCListLabels.mli  | 42 ++++++++++++++++++------------------
 src/core/CCParse.ml        | 10 ++++-----
 src/core/CCRandom.ml       |  6 +++---
 src/core/CCRandom.mli      |  2 +-
 src/core/CCString.cppo.ml  | 22 ++++++++-----------
 src/core/CCVector.ml       |  2 +-
 src/core/CCVector.mli      |  2 +-
 src/data/CCCache.ml        |  6 +++++-
 src/data/CCDeque.ml        |  7 +++---
 src/data/CCDeque.mli       |  4 ++--
 src/data/CCFQueue.ml       |  6 +++++-
 src/data/CCHashTrie.ml     |  6 ++++--
 src/data/CCIntMap.ml       |  8 ++++---
 src/data/CCMixmap.ml       |  2 +-
 src/data/CCMixtbl.ml       |  2 +-
 src/data/CCRAL.ml          |  4 ++--
 src/data/CCRAL.mli         |  4 ++--
 src/data/CCSimple_queue.ml |  6 +++---
 src/data/CCTrie.ml         |  6 +++++-
 src/data/CCTrie.mli        |  1 +
 src/iter/CCKTree.ml        |  4 ++--
 src/sexp/CCSexp.ml         |  2 +-
 src/sexp/CCSexp_lex.mll    |  3 +--
 src/threads/CCPool.ml      |  6 +++++-
 src/threads/CCTimer.ml     |  2 ++
 35 files changed, 188 insertions(+), 170 deletions(-)

diff --git a/_oasis b/_oasis
index 99dfa6f1..aabfca6a 100644
--- a/_oasis
+++ b/_oasis
@@ -50,14 +50,14 @@ Library "containers"
 Library "containers_unix"
   Path:             src/unix
   Modules:          CCUnix
-  BuildDepends:     bytes, result, unix
+  BuildDepends:     containers, unix
   FindlibParent:    containers
   FindlibName:      unix
 
 Library "containers_sexp"
   Path:             src/sexp
   Modules:          CCSexp, CCSexp_lex
-  BuildDepends:     bytes, result
+  BuildDepends:     containers
   FindlibParent:    containers
   FindlibName:      sexp
 
@@ -66,10 +66,12 @@ Library "containers_data"
   Modules:          CCMultiMap, CCMultiSet, CCTrie, CCFlatHashtbl, CCCache,
                     CCPersistentHashtbl, CCDeque, CCFQueue, CCBV, CCMixtbl,
                     CCMixmap, CCRingBuffer, CCIntMap, CCPersistentArray,
-                    CCMixset, CCGraph, CCHashSet, CCBitField,
+                    CCMixset,
+                    #CCGraph,
+                    CCHashSet, CCBitField,
                     CCHashTrie, CCWBTree, CCRAL, CCSimple_queue,
                     CCImmutArray, CCHet, CCZipper
-  BuildDepends:     bytes
+  BuildDepends:     containers
   # BuildDepends:     bytes, bisect_ppx
   FindlibParent:    containers
   FindlibName:      data
@@ -77,6 +79,7 @@ Library "containers_data"
 Library "containers_iter"
   Path:             src/iter
   Modules:          CCKTree, CCKList, CCLazy_list
+  BuildDepends:     containers
   FindlibParent:    containers
   FindlibName:      iter
 
diff --git a/src/core/CCBool.ml b/src/core/CCBool.ml
index 087d0101..89a6a9e5 100644
--- a/src/core/CCBool.ml
+++ b/src/core/CCBool.ml
@@ -3,7 +3,7 @@
 
 type t = bool
 
-let equal (a:bool) b = a=b
+let equal (a:bool) b = Pervasives.(=) a b
 
 let compare (a:bool) b = Pervasives.compare a b
 
diff --git a/src/core/CCChar.ml b/src/core/CCChar.ml
index 55900bd6..1825afbc 100644
--- a/src/core/CCChar.ml
+++ b/src/core/CCChar.ml
@@ -6,7 +6,7 @@
 
 include Char
 
-let equal (a:char) b = a=b
+let equal (a:char) b = Pervasives.(=) a b
 
 let pp = Buffer.add_char
 let print = Format.pp_print_char
@@ -15,12 +15,10 @@ let of_int_exn = Char.chr
 let of_int c = try Some (of_int_exn c) with _ -> None
 let to_int = Char.code
 
-let lowercase_ascii c =
-  if c >= 'A' && c <= 'Z'
-  then Char.unsafe_chr (Char. code c + 32)
-  else c
+let lowercase_ascii = function
+  | 'A'..'Z' as c -> Char.unsafe_chr (Char. code c + 32)
+  | c -> c
 
-let uppercase_ascii c =
-  if c >= 'a' && c <= 'z'
-  then Char.unsafe_chr (Char.code c - 32)
-  else c
+let uppercase_ascii = function
+  | 'a'..'z' as c -> Char.unsafe_chr (Char.code c - 32)
+  | c -> c
diff --git a/src/core/CCEqual.ml b/src/core/CCEqual.ml
index f879bd05..769dbbb7 100644
--- a/src/core/CCEqual.ml
+++ b/src/core/CCEqual.ml
@@ -5,12 +5,12 @@
 
 type 'a t = 'a -> 'a -> bool
 
-let poly = (=)
+let poly = Pervasives.(=)
 
-let int : int t = (=)
-let string : string t = (=)
-let bool : bool t = (=)
-let float : float t = (=)
+let int : int t = CCInt.equal
+let string : string t = CCString.equal
+let bool : bool t = CCBool.equal
+let float : float t = CCFloat.equal
 let unit () () = true
 
 let rec list f l1 l2 = match l1, l2 with
diff --git a/src/core/CCFloat.ml b/src/core/CCFloat.ml
index 2e7fcc41..cb4062b9 100644
--- a/src/core/CCFloat.ml
+++ b/src/core/CCFloat.ml
@@ -9,6 +9,16 @@ type fpclass = Pervasives.fpclass =
   | FP_infinite
   | FP_nan
 
+module Infix = struct
+  let (=) = Pervasives.(=)
+  let (<>) = Pervasives.(<>)
+  let (<) = Pervasives.(<)
+  let (>) = Pervasives.(>)
+  let (<=) = Pervasives.(<=)
+  let (>=) = Pervasives.(>=)
+end
+include Infix
+
 let nan = Pervasives.nan
 
 let infinity = Pervasives.infinity
@@ -84,13 +94,3 @@ let random_range i j st = i +. random (j-.i) st
 let equal_precision ~epsilon a b = abs_float (a-.b) < epsilon
 
 let classify = Pervasives.classify_float
-
-module Infix = struct
-  let (=) = Pervasives.(=)
-  let (<>) = Pervasives.(<>)
-  let (<) = Pervasives.(<)
-  let (>) = Pervasives.(>)
-  let (<=) = Pervasives.(<=)
-  let (>=) = Pervasives.(>=)
-end
-include Infix
diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index eb37fccc..f4b8adb0 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -77,7 +77,7 @@ let floor_div a n =
 
 let rem a n =
   let y = a mod n in
-  if (y < 0) <> (n < 0) && y <> 0 then
+  if not (CCBool.equal (y < 0) (n < 0)) && y <> 0 then
     y + n
   else
     y
diff --git a/src/core/CCInt64.ml b/src/core/CCInt64.ml
index f9ab3841..9ac33506 100644
--- a/src/core/CCInt64.ml
+++ b/src/core/CCInt64.ml
@@ -28,7 +28,7 @@ let (lsr) = shift_right_logical
 
 let (asr) = shift_right
 
-let equal (x:t) y = x=y
+let equal (x:t) y = Pervasives.(=) x y
 
 let hash x = Pervasives.abs (to_int x)
 
diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index f7552587..98c8ecb1 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -537,7 +537,7 @@ let map_product_l f l =
     cmp_lii_unord (cartesian_product l) (map_product_l CCFun.id l))
 *)
 
-let sorted_merge ?(cmp=Pervasives.compare) l1 l2 =
+let sorted_merge ~cmp l1 l2 =
   let rec recurse cmp acc l1 l2 = match l1,l2 with
     | [], _ -> List.rev_append acc l2
     | _, [] -> List.rev_append acc l1
@@ -560,7 +560,7 @@ let sorted_merge ?(cmp=Pervasives.compare) l1 l2 =
     List.length (sorted_merge l1 l2) = List.length l1 + List.length l2)
 *)
 
-let sort_uniq (type elt) ?(cmp=Pervasives.compare) l =
+let sort_uniq (type elt) ~cmp l =
   let module S = Set.Make(struct
       type t = elt
       let compare = cmp
@@ -574,7 +574,7 @@ let sort_uniq (type elt) ?(cmp=Pervasives.compare) l =
   sort_uniq [10;10;10;10;1;10] = [1;10]
 *)
 
-let is_sorted ?(cmp=Pervasives.compare) l =
+let is_sorted ~cmp l =
   let rec aux cmp = function
     | [] | [_] -> true
     | x :: ((y :: _) as tail) -> cmp x y <= 0 && aux cmp tail
@@ -586,7 +586,7 @@ let is_sorted ?(cmp=Pervasives.compare) l =
     is_sorted (List.sort Pervasives.compare l))
 *)
 
-let sorted_insert ?(cmp=Pervasives.compare) ?(uniq=false) x l =
+let sorted_insert ~cmp ?(uniq=false) x l =
   let rec aux cmp uniq x left l = match l with
     | [] -> List.rev_append left [x]
     | y :: tail ->
@@ -615,7 +615,7 @@ let sorted_insert ?(cmp=Pervasives.compare) ?(uniq=false) x l =
       List.mem x (sorted_insert x l))
 *)
 
-let uniq_succ ?(eq=(=)) l =
+let uniq_succ ~eq l =
   let rec f acc l = match l with
     | [] -> List.rev acc
     | [x] -> List.rev (x::acc)
@@ -628,7 +628,7 @@ let uniq_succ ?(eq=(=)) l =
   uniq_succ [1;1;2;3;1;6;6;4;6;1] = [1;2;3;1;6;4;6;1]
 *)
 
-let group_succ ?(eq=(=)) l =
+let group_succ ~eq l =
   let rec f ~eq acc cur l = match cur, l with
     | [], [] -> List.rev acc
     | _::_, [] -> List.rev (List.rev cur :: acc)
@@ -647,7 +647,7 @@ let group_succ ?(eq=(=)) l =
     = [[1, 1; 1, 2; 1, 3]; [2, 0]]
 *)
 
-let sorted_merge_uniq ?(cmp=Pervasives.compare) l1 l2 =
+let sorted_merge_uniq ~cmp l1 l2 =
   let push ~cmp acc x = match acc with
     | [] -> [x]
     | y :: _ when cmp x y > 0 -> x :: acc
@@ -746,7 +746,7 @@ let sublists_of_len ?(last=fun _ -> None) ?offset n l =
   (* add sub-lists of [l] to [acc] *)
   let rec aux acc l =
     let group = take n l in
-    if group=[] then acc (* this was the last group, we are done *)
+    if is_empty group then acc (* this was the last group, we are done *)
     else if List.length group < n (* last group, with missing elements *)
     then match last group with
       | None -> acc
@@ -880,7 +880,7 @@ let find_idx p l = find_mapi (fun i x -> if p x then Some (i, x) else None) l
   find_map (fun x -> if x=3 then Some "a" else None) [1;2;4;5] = None
 *)
 
-let remove ?(eq=(=)) ~x l =
+let remove ~eq ~x l =
   let rec remove' eq x acc l = match l with
     | [] -> List.rev acc
     | y :: tail when eq x y -> remove' eq x acc tail
@@ -952,16 +952,16 @@ let all_ok l =
   (Error "e2") (all_ok [Ok 1; Error "e2"; Error "e3"; Ok 4])
 *)
 
-let mem ?(eq=(=)) x l =
+let mem ~eq x l =
   let rec search eq x l = match l with
     | [] -> false
     | y::l' -> eq x y || search eq x l'
   in search eq x l
 
-let add_nodup ?(eq=(=)) x l =
+let add_nodup ~eq x l =
   if mem ~eq x l then l else x::l
 
-let remove_one ?(eq=(=)) x l =
+let remove_one ~eq x l =
   let rec remove_one ~eq x acc l = match l with
     | [] -> assert false
     | y :: tl when eq x y -> List.rev_append acc tl
@@ -978,12 +978,12 @@ let remove_one ?(eq=(=)) x l =
     not (mem x l) || List.length (remove_one x l) = List.length l - 1)
 *)
 
-let subset ?(eq=(=)) l1 l2 =
+let subset ~eq l1 l2 =
   List.for_all
     (fun t -> mem ~eq t l2)
     l1
 
-let uniq ?(eq=(=)) l =
+let uniq ~eq l =
   let rec uniq eq acc l = match l with
     | [] -> List.rev acc
     | x::xs when List.exists (eq x) xs -> uniq eq acc xs
@@ -999,7 +999,7 @@ let uniq ?(eq=(=)) l =
     sort_uniq l = (uniq l |> sort Pervasives.compare))
   *)
 
-let union ?(eq=(=)) l1 l2 =
+let union ~eq l1 l2 =
   let rec union eq acc l1 l2 = match l1 with
     | [] -> List.rev_append acc l2
     | x::xs when mem ~eq x l2 -> union eq acc xs l2
@@ -1010,7 +1010,7 @@ let union ?(eq=(=)) l1 l2 =
   union [1;2;4] [2;3;4;5] = [1;2;3;4;5]
 *)
 
-let inter ?(eq=(=)) l1 l2 =
+let inter ~eq l1 l2 =
   let rec inter eq acc l1 l2 = match l1 with
     | [] -> List.rev acc
     | x::xs when mem ~eq x l2 -> inter eq (x::acc) xs l2
@@ -1201,9 +1201,9 @@ module Assoc = struct
     | (y,z)::l' ->
       if eq x y then z else search_exn eq l' x
 
-  let get_exn ?(eq=(=)) x l = search_exn eq l x
+  let get_exn ~eq x l = search_exn eq l x
 
-  let get ?(eq=(=)) x l =
+  let get ~eq x l =
     try Some (search_exn eq l x)
     with Not_found -> None
 
@@ -1224,7 +1224,7 @@ module Assoc = struct
       then f x (Some y') (List.rev_append acc l')
       else search_set eq ((x',y')::acc) l' x ~f
 
-  let set ?(eq=(=)) x y l =
+  let set ~eq x y l =
     search_set eq [] l x
       ~f:(fun x _ l -> (x,y)::l)
 
@@ -1235,7 +1235,7 @@ module Assoc = struct
       = [1, "1"; 2, "2"; 3, "3"]
   *)
 
-  let mem ?(eq=(=)) x l =
+  let mem ~eq x l =
     try ignore (search_exn eq l x); true
     with Not_found -> false
 
@@ -1244,7 +1244,7 @@ module Assoc = struct
     not (Assoc.mem 4 [1,"1"; 2,"2"; 3, "3"])
   *)
 
-  let update ?(eq=(=)) ~f x l =
+  let update ~eq ~f x l =
     search_set eq [] l x
       ~f:(fun x opt_y rest ->
         match f opt_y with
@@ -1262,7 +1262,7 @@ module Assoc = struct
         ~f:(function None -> Some "3" | _ -> assert false) |> lsort)
   *)
 
-  let remove ?(eq=(=)) x l =
+  let remove ~eq x l =
     search_set eq [] l x
       ~f:(fun _ opt_y rest -> match opt_y with
         | None -> l  (* keep as is *)
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index f83407bf..9e069337 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -256,7 +256,7 @@ val find_idx : ('a -> bool) -> 'a t -> (int * 'a) option
 (** [find_idx p x] returns [Some (i,x)] where [x] is the [i]-th element of [l],
     and [p x] holds. Otherwise returns [None] *)
 
-val remove : ?eq:('a -> 'a -> bool) -> x:'a -> 'a t -> 'a t
+val remove : eq:('a -> 'a -> bool) -> x:'a -> 'a t -> 'a t
 (** [remove ~x l] removes every instance of [x] from [l]. Tailrec.
     @param eq equality function
     @since 0.11 *)
@@ -284,23 +284,23 @@ val all_ok : ('a, 'err) Result.result t -> ('a t, 'err) Result.result
     or [Error e] otherwise (with the first error met).
     @since 1.3 *)
 
-val sorted_merge : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
+val sorted_merge : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** Merges elements from both sorted list *)
 
-val sort_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list
+val sort_uniq : cmp:('a -> 'a -> int) -> 'a list -> 'a list
 (** Sort the list and remove duplicate elements *)
 
-val sorted_merge_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
+val sorted_merge_uniq : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** [sorted_merge_uniq l1 l2] merges the sorted lists [l1] and [l2] and
     removes duplicates
     @since 0.10 *)
 
-val is_sorted : ?cmp:('a -> 'a -> int) -> 'a list -> bool
+val is_sorted : cmp:('a -> 'a -> int) -> 'a list -> bool
 (** [is_sorted l] returns [true] iff [l] is sorted (according to given order)
     @param cmp the comparison function (default [Pervasives.compare])
     @since 0.17 *)
 
-val sorted_insert : ?cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a list
+val sorted_insert : cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a list
 (** [sorted_insert x l] inserts [x] into [l] such that, if [l] was sorted,
     then [sorted_insert x l] is sorted too.
     @param uniq if true and [x] is already in sorted position in [l], then
@@ -313,14 +313,14 @@ val sorted_insert : ?cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a
       is_sorted (sorted_insert x l))
 *)
 
-val uniq_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list
+val uniq_succ : eq:('a -> 'a -> bool) -> 'a list -> 'a list
 (** [uniq_succ l] removes duplicate elements that occur one next to the other.
     Examples:
     [uniq_succ [1;2;1] = [1;2;1]]
     [uniq_succ [1;1;2] = [1;2]]
     @since 0.10 *)
 
-val group_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list list
+val group_succ : eq:('a -> 'a -> bool) -> 'a list -> 'a list list
 (** [group_succ ~eq l] groups together consecutive elements that are equal
     according to [eq]
     @since 0.11 *)
@@ -362,30 +362,30 @@ val remove_at_idx : int -> 'a t -> 'a t
     Those operations maintain the invariant that the list does not
     contain duplicates (if it already satisfies it) *)
 
-val add_nodup : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
+val add_nodup : eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
 (** [add_nodup x set] adds [x] to [set] if it was not already present. Linear time.
     @since 0.11 *)
 
-val remove_one : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
+val remove_one : eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
 (** [remove_one x set] removes one occurrence of [x] from [set]. Linear time.
     @since 0.11 *)
 
-val mem : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
+val mem : eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
 (** Membership to the list. Linear time *)
 
-val subset : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+val subset : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 (** Test for inclusion *)
 
-val uniq : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t
+val uniq : eq:('a -> 'a -> bool) -> 'a t -> 'a t
 (** Remove duplicates w.r.t the equality predicate.
     Complexity is quadratic in the length of the list, but the order
     of elements is preserved. If you wish for a faster de-duplication
     but do not care about the order, use {!sort_uniq}*)
 
-val union : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
+val union : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
 (** List union. Complexity is product of length of inputs. *)
 
-val inter : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
+val inter : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
 (** List intersection. Complexity is product of length of inputs. *)
 
 (** {2 Other Constructors} *)
@@ -423,28 +423,28 @@ val repeat : int -> 'a t -> 'a t
 module Assoc : sig
   type ('a, 'b) t = ('a*'b) list
 
-  val get : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b option
+  val get : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b option
   (** Find the element *)
 
-  val get_exn : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b
+  val get_exn : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b
   (** Same as [get], but unsafe
       @raise Not_found if the element is not present *)
 
-  val set : ?eq:('a->'a->bool) -> 'a -> 'b -> ('a,'b) t -> ('a,'b) t
+  val set : eq:('a->'a->bool) -> 'a -> 'b -> ('a,'b) t -> ('a,'b) t
   (** Add the binding into the list (erase it if already present) *)
 
-  val mem : ?eq:('a->'a->bool) -> 'a -> ('a,_) t -> bool
+  val mem : eq:('a->'a->bool) -> 'a -> ('a,_) t -> bool
   (** [mem x l] returns [true] iff [x] is a key in [l]
       @since 0.16 *)
 
   val update :
-    ?eq:('a->'a->bool) -> f:('b option -> 'b option) -> 'a -> ('a,'b) t -> ('a,'b) t
+    eq:('a->'a->bool) -> f:('b option -> 'b option) -> 'a -> ('a,'b) t -> ('a,'b) t
   (** [update k ~f l] updates [l] on the key [k], by calling [f (get l k)]
       and removing [k] if it returns [None], mapping [k] to [v'] if it
       returns [Some v']
       @since 0.16 *)
 
-  val remove : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> ('a,'b) t
+  val remove : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> ('a,'b) t
   (** [remove x l] removes the first occurrence of [k] from [l].
       @since 0.17 *)
 end
diff --git a/src/core/CCListLabels.ml b/src/core/CCListLabels.ml
index 61df2913..d90aa088 100644
--- a/src/core/CCListLabels.ml
+++ b/src/core/CCListLabels.ml
@@ -331,7 +331,7 @@ let pure = return
 
 let (<*>) funs l = product (fun f x -> f x) funs l
 
-let sorted_merge ?(cmp=Pervasives.compare) l1 l2 =
+let sorted_merge ~cmp l1 l2 =
   let rec recurse cmp acc l1 l2 = match l1,l2 with
     | [], _ -> List.rev_append acc l2
     | _, [] -> List.rev_append acc l1
@@ -354,7 +354,7 @@ let sorted_merge ?(cmp=Pervasives.compare) l1 l2 =
     List.length (sorted_merge l1 l2) = List.length l1 + List.length l2)
 *)
 
-let sort_uniq (type elt) ?(cmp=Pervasives.compare) l =
+let sort_uniq (type elt) ~cmp l =
   let module S = Set.Make(struct
       type t = elt
       let compare = cmp
@@ -368,7 +368,7 @@ let sort_uniq (type elt) ?(cmp=Pervasives.compare) l =
   sort_uniq [10;10;10;10;1;10] = [1;10]
 *)
 
-let is_sorted ?(cmp=Pervasives.compare) l =
+let is_sorted ~cmp l =
   let rec aux cmp = function
     | [] | [_] -> true
     | x :: ((y :: _) as tail) -> cmp x y <= 0 && aux cmp tail
@@ -380,7 +380,7 @@ let is_sorted ?(cmp=Pervasives.compare) l =
     is_sorted (List.sort Pervasives.compare l))
 *)
 
-let sorted_insert ?(cmp=Pervasives.compare) ?(uniq=false) x l =
+let sorted_insert ~cmp ?(uniq=false) x l =
   let rec aux cmp uniq x left l = match l with
     | [] -> List.rev_append left [x]
     | y :: tail ->
@@ -409,7 +409,7 @@ let sorted_insert ?(cmp=Pervasives.compare) ?(uniq=false) x l =
       List.mem x (sorted_insert x l))
 *)
 
-let uniq_succ ?(eq=(=)) l =
+let uniq_succ ~eq l =
   let rec f acc l = match l with
     | [] -> List.rev acc
     | [x] -> List.rev (x::acc)
@@ -422,7 +422,7 @@ let uniq_succ ?(eq=(=)) l =
   uniq_succ [1;1;2;3;1;6;6;4;6;1] = [1;2;3;1;6;4;6;1]
 *)
 
-let group_succ ?(eq=(=)) l =
+let group_succ ~eq l =
   let rec f ~eq acc cur l = match cur, l with
     | [], [] -> List.rev acc
     | _::_, [] -> List.rev (List.rev cur :: acc)
@@ -441,7 +441,7 @@ let group_succ ?(eq=(=)) l =
     = [[1, 1; 1, 2; 1, 3]; [2, 0]]
 *)
 
-let sorted_merge_uniq ?(cmp=Pervasives.compare) l1 l2 =
+let sorted_merge_uniq ~cmp l1 l2 =
   let push ~cmp acc x = match acc with
     | [] -> [x]
     | y :: _ when cmp x y > 0 -> x :: acc
@@ -540,7 +540,7 @@ let sublists_of_len ?(last=fun _ -> None) ?offset n l =
   (* add sub-lists of [l] to [acc] *)
   let rec aux acc l =
     let group = take n l in
-    if group=[] then acc (* this was the last group, we are done *)
+    if is_empty group then acc (* this was the last group, we are done *)
     else if List.length group < n (* last group, with missing elements *)
     then match last group with
       | None -> acc
@@ -654,7 +654,7 @@ let find_idx p l = find_mapi (fun i x -> if p x then Some (i, x) else None) l
   find_map (fun x -> if x=3 then Some "a" else None) [1;2;4;5] = None
 *)
 
-let remove ?(eq=(=)) ~x l =
+let remove ~eq ~x l =
   let rec remove' eq x acc l = match l with
     | [] -> List.rev acc
     | y :: tail when eq x y -> remove' eq x acc tail
@@ -684,16 +684,16 @@ let filter_map f l =
       [ 1; 2; 3; 4; 5; 6 ])
 *)
 
-let mem ?(eq=(=)) x l =
+let mem ~eq x l =
   let rec search eq x l = match l with
     | [] -> false
     | y::l' -> eq x y || search eq x l'
   in search eq x l
 
-let add_nodup ?(eq=(=)) x l =
+let add_nodup ~eq x l =
   if mem ~eq x l then l else x::l
 
-let remove_one ?(eq=(=)) x l =
+let remove_one ~eq x l =
   let rec remove_one ~eq x acc l = match l with
     | [] -> assert false
     | y :: tl when eq x y -> List.rev_append acc tl
@@ -710,12 +710,12 @@ let remove_one ?(eq=(=)) x l =
     not (mem x l) || List.length (remove_one x l) = List.length l - 1)
 *)
 
-let subset ?(eq=(=)) l1 l2 =
+let subset ~eq l1 l2 =
   List.for_all
     (fun t -> mem ~eq t l2)
     l1
 
-let uniq ?(eq=(=)) l =
+let uniq ~eq l =
   let rec uniq eq acc l = match l with
     | [] -> List.rev acc
     | x::xs when List.exists (eq x) xs -> uniq eq acc xs
@@ -726,7 +726,7 @@ let uniq ?(eq=(=)) l =
   uniq [1;1;2;2;3;4;4;2;4;1;5] |> List.sort Pervasives.compare = [1;2;3;4;5]
 *)
 
-let union ?(eq=(=)) l1 l2 =
+let union ~eq l1 l2 =
   let rec union eq acc l1 l2 = match l1 with
     | [] -> List.rev_append acc l2
     | x::xs when mem ~eq x l2 -> union eq acc xs l2
@@ -737,7 +737,7 @@ let union ?(eq=(=)) l1 l2 =
   union [1;2;4] [2;3;4;5] = [1;2;3;4;5]
 *)
 
-let inter ?(eq=(=)) l1 l2 =
+let inter ~eq l1 l2 =
   let rec inter eq acc l1 l2 = match l1 with
     | [] -> List.rev acc
     | x::xs when mem ~eq x l2 -> inter eq (x::acc) xs l2
@@ -928,9 +928,9 @@ module Assoc = struct
     | (y,z)::l' ->
       if eq x y then z else search_exn eq l' x
 
-  let get_exn ?(eq=(=)) x l = search_exn eq l x
+  let get_exn ~eq x l = search_exn eq l x
 
-  let get ?(eq=(=)) x l =
+  let get ~eq x l =
     try Some (search_exn eq l x)
     with Not_found -> None
 
@@ -951,7 +951,7 @@ module Assoc = struct
       then f x (Some y') (List.rev_append acc l')
       else search_set eq ((x',y')::acc) l' x ~f
 
-  let set ?(eq=(=)) x y l =
+  let set ~eq x y l =
     search_set eq [] l x
       ~f:(fun x _ l -> (x,y)::l)
 
@@ -962,7 +962,7 @@ module Assoc = struct
       = [1, "1"; 2, "2"; 3, "3"]
   *)
 
-  let mem ?(eq=(=)) x l =
+  let mem ~eq x l =
     try ignore (search_exn eq l x); true
     with Not_found -> false
 
@@ -971,7 +971,7 @@ module Assoc = struct
     not (Assoc.mem 4 [1,"1"; 2,"2"; 3, "3"])
   *)
 
-  let update ?(eq=(=)) ~f x l =
+  let update ~eq ~f x l =
     search_set eq [] l x
       ~f:(fun x opt_y rest ->
         match f opt_y with
@@ -989,7 +989,7 @@ module Assoc = struct
         ~f:(function None -> Some "3" | _ -> assert false) |> lsort)
   *)
 
-  let remove ?(eq=(=)) x l =
+  let remove ~eq x l =
     search_set eq [] l x
       ~f:(fun _ opt_y rest -> match opt_y with
         | None -> l  (* keep as is *)
diff --git a/src/core/CCListLabels.mli b/src/core/CCListLabels.mli
index 535eab06..45c86e22 100644
--- a/src/core/CCListLabels.mli
+++ b/src/core/CCListLabels.mli
@@ -178,7 +178,7 @@ val find_idx : f:('a -> bool) -> 'a t -> (int * 'a) option
 (** [find_idx p x] returns [Some (i,x)] where [x] is the [i]-th element of [l],
     and [p x] holds. Otherwise returns [None] *)
 
-val remove : ?eq:('a -> 'a -> bool) -> key:'a -> 'a t -> 'a t
+val remove : eq:('a -> 'a -> bool) -> key:'a -> 'a t -> 'a t
 (** [remove ~key l] removes every instance of [key] from [l]. Tailrec.
     @param eq equality function
     @since 0.11 *)
@@ -186,23 +186,23 @@ val remove : ?eq:('a -> 'a -> bool) -> key:'a -> 'a t -> 'a t
 val filter_map : f:('a -> 'b option) -> 'a t -> 'b t
 (** Map and remove elements at the same time *)
 
-val sorted_merge : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
+val sorted_merge : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** Merges elements from both sorted list *)
 
-val sort_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list
+val sort_uniq : cmp:('a -> 'a -> int) -> 'a list -> 'a list
 (** Sort the list and remove duplicate elements *)
 
-val sorted_merge_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
+val sorted_merge_uniq : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** [sorted_merge_uniq l1 l2] merges the sorted lists [l1] and [l2] and
     removes duplicates
     @since 0.10 *)
 
-val is_sorted : ?cmp:('a -> 'a -> int) -> 'a list -> bool
+val is_sorted : cmp:('a -> 'a -> int) -> 'a list -> bool
 (** [is_sorted l] returns [true] iff [l] is sorted (according to given order)
     @param cmp the comparison function (default [Pervasives.compare])
     @since 0.17 *)
 
-val sorted_insert : ?cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a list
+val sorted_insert : cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a list
 (** [sorted_insert x l] inserts [x] into [l] such that, if [l] was sorted,
     then [sorted_insert x l] is sorted too.
     @param uniq if true and [x] is already in sorted position in [l], then
@@ -215,14 +215,14 @@ val sorted_insert : ?cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a
       is_sorted (sorted_insert x l))
 *)
 
-val uniq_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list
+val uniq_succ : eq:('a -> 'a -> bool) -> 'a list -> 'a list
 (** [uniq_succ l] removes duplicate elements that occur one next to the other.
     Examples:
     [uniq_succ [1;2;1] = [1;2;1]]
     [uniq_succ [1;1;2] = [1;2]]
     @since 0.10 *)
 
-val group_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list list
+val group_succ : eq:('a -> 'a -> bool) -> 'a list -> 'a list list
 (** [group_succ ~eq l] groups together consecutive elements that are equal
     according to [eq]
     @since 0.11 *)
@@ -259,30 +259,30 @@ val remove_at_idx : int -> 'a t -> 'a t
     Those operations maintain the invariant that the list does not
     contain duplicates (if it already satisfies it) *)
 
-val add_nodup : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
+val add_nodup : eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
 (** [add_nodup x set] adds [x] to [set] if it was not already present. Linear time.
     @since 0.11 *)
 
-val remove_one : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
+val remove_one : eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
 (** [remove_one x set] removes one occurrence of [x] from [set]. Linear time.
     @since 0.11 *)
 
-val mem : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
+val mem : eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
 (** Membership to the list. Linear time *)
 
-val subset : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+val subset : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 (** Test for inclusion *)
 
-val uniq : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t
+val uniq : eq:('a -> 'a -> bool) -> 'a t -> 'a t
 (** Remove duplicates w.r.t the equality predicate.
     Complexity is quadratic in the length of the list, but the order
     of elements is preserved. If you wish for a faster de-duplication
     but do not care about the order, use {!sort_uniq}*)
 
-val union : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
+val union : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
 (** List union. Complexity is product of length of inputs. *)
 
-val inter : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
+val inter : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
 (** List intersection. Complexity is product of length of inputs. *)
 
 (** {2 Other Constructors} *)
@@ -320,28 +320,28 @@ val repeat : int -> 'a t -> 'a t
 module Assoc : sig
   type ('a, 'b) t = ('a*'b) list
 
-  val get : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b option
+  val get : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b option
   (** Find the element *)
 
-  val get_exn : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b
+  val get_exn : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> 'b
   (** Same as [get], but unsafe
       @raise Not_found if the element is not present *)
 
-  val set : ?eq:('a->'a->bool) -> 'a -> 'b -> ('a,'b) t -> ('a,'b) t
+  val set : eq:('a->'a->bool) -> 'a -> 'b -> ('a,'b) t -> ('a,'b) t
   (** Add the binding into the list (erase it if already present) *)
 
-  val mem : ?eq:('a->'a->bool) -> 'a -> ('a,_) t -> bool
+  val mem : eq:('a->'a->bool) -> 'a -> ('a,_) t -> bool
   (** [mem x l] returns [true] iff [x] is a key in [l]
       @since 0.16 *)
 
   val update :
-    ?eq:('a->'a->bool) -> f:('b option -> 'b option) -> 'a -> ('a,'b) t -> ('a,'b) t
+    eq:('a->'a->bool) -> f:('b option -> 'b option) -> 'a -> ('a,'b) t -> ('a,'b) t
   (** [update k ~f l] updates [l] on the key [k], by calling [f (get l k)]
       and removing [k] if it returns [None], mapping [k] to [v'] if it
       returns [Some v']
       @since 0.16 *)
 
-  val remove : ?eq:('a->'a->bool) -> 'a -> ('a,'b) t -> ('a,'b) t
+  val remove : eq:('a->'a->bool) -> 'a -> ('a,'b) t -> ('a,'b) t
   (** [remove x l] removes the first occurrence of [k] from [l].
       @since 0.17 *)
 end
diff --git a/src/core/CCParse.ml b/src/core/CCParse.ml
index f581784a..01511e0a 100644
--- a/src/core/CCParse.ml
+++ b/src/core/CCParse.ml
@@ -87,7 +87,7 @@ let next st ~ok ~err =
   else (
     let c = st.str.[st.i] in
     st.i <- st.i + 1;
-    if c='\n'
+    if CCChar.equal c '\n'
     then (st.lnum <- st.lnum + 1; st.cnum <- 1)
     else st.cnum <- st.cnum + 1;
     ok c
@@ -146,7 +146,7 @@ let char c =
   let msg = Printf.sprintf "expected '%c'" c in
   fun st ~ok ~err ->
     next st ~err
-      ~ok:(fun c' -> if c=c' then ok c else fail_ ~err st (const_ msg))
+      ~ok:(fun c' -> if CCChar.equal c c' then ok c else fail_ ~err st (const_ msg))
 
 let char_if p st ~ok ~err =
   next st ~err
@@ -164,7 +164,7 @@ let chars_if p st ~ok ~err:_ =
 let chars1_if p st ~ok ~err =
   chars_if p st ~err
     ~ok:(fun s ->
-      if s = ""
+      if CCString.is_empty s
       then fail_ ~err st (const_ "unexpected sequence of chars")
       else ok s)
 
@@ -231,7 +231,7 @@ let string s st ~ok ~err =
     else
       next st ~err
         ~ok:(fun c ->
-          if c = s.[i]
+          if CCChar.equal c s.[i]
           then check (i+1)
           else fail_ ~err st (fun () -> Printf.sprintf "expected \"%s\"" s))
   in
@@ -386,7 +386,7 @@ module U = struct
       skip_white <* string stop
 
   let int =
-    chars1_if (fun c -> is_num c || c='-')
+    chars1_if (fun c -> is_num c || CCChar.equal c '-')
     >>= fun s ->
     try return (int_of_string s)
     with Failure _ -> fail "expected an int"
diff --git a/src/core/CCRandom.ml b/src/core/CCRandom.ml
index bcc83111..0bf23101 100644
--- a/src/core/CCRandom.ml
+++ b/src/core/CCRandom.ml
@@ -77,7 +77,7 @@ let replicate n g st =
   in aux [] n
 
 (* Sample without replacement using rejection sampling. *)
-let sample_without_replacement (type elt)  ?(compare=compare) k (rng:elt t) st=
+let sample_without_replacement (type elt) ~compare k (rng:elt t) st=
   let module S = Set.Make(struct type t=elt let compare = compare end) in
   let rec aux s k =
     if k <= 0 then
@@ -118,7 +118,7 @@ let _diff_list ~last l =
 let split_list i ~len st =
   if len <= 1 then invalid_arg "Random.split_list";
   if i >= len then
-    let xs = sample_without_replacement (len-1) (int_range 1 (i-1)) st in
+    let xs = sample_without_replacement ~compare:CCInt.compare (len-1) (int_range 1 (i-1)) st in
     _diff_list ( 0::xs ) ~last:i
   else
     None
@@ -221,7 +221,7 @@ let uniformity_test ?(size_hint=10) k rng st =
   let confidence = 4. in
   let std = confidence *. (sqrt (kf *. variance)) in
   let predicate _key n acc =
-    acc && abs_float (average -. float_of_int n) < std in
+    CCFloat.Infix.(acc && abs_float (average -. float_of_int n) < std) in
   Hashtbl.fold predicate histogram true
 
 (*$T split_list
diff --git a/src/core/CCRandom.mli b/src/core/CCRandom.mli
index ffb32cfb..de76e90d 100644
--- a/src/core/CCRandom.mli
+++ b/src/core/CCRandom.mli
@@ -56,7 +56,7 @@ val replicate : int -> 'a t -> 'a list t
     randomly using [g] *)
 
 val sample_without_replacement:
-  ?compare:('a -> 'a -> int) -> int -> 'a t -> 'a list t
+  compare:('a -> 'a -> int) -> int -> 'a t -> 'a list t
 (** [sample_without_replacement n g] makes a list of [n] elements which are all
     generated randomly using [g] with the added constraint that none of the generated
     random values are equal
diff --git a/src/core/CCString.cppo.ml b/src/core/CCString.cppo.ml
index 9eb3c329..5e8b94b1 100644
--- a/src/core/CCString.cppo.ml
+++ b/src/core/CCString.cppo.ml
@@ -32,7 +32,7 @@ module type S = sig
   val print : Format.formatter -> t -> unit
 end
 
-let equal (a:string) b = a=b
+let equal (a:string) b = Pervasives.(=) a b
 
 let compare = String.compare
 
@@ -66,7 +66,7 @@ let _is_sub ~sub i s j ~len =
   let rec check k =
     if k = len
     then true
-    else sub.[i+k] = s.[j+k] && check (k+1)
+    else Char.equal sub.[i+k] s.[j+k] && check (k+1)
   in
   j+len <= String.length s && check 0
 
@@ -114,7 +114,7 @@ module Find = struct
           let j = ref 0 in
           while !i < len do
             match !j with
-              | _ when get str (!i-1) = get str !j ->
+              | _ when Char.equal (get str (!i-1)) (get str !j) ->
                 (* substring starting at !j continues matching current char *)
                 incr j;
                 failure.(!i) <- !j;
@@ -146,7 +146,7 @@ module Find = struct
     while !j < pat_len && !i + !j < len do
       let c = String.get s (!i + !j) in
       let expected = String.get pattern.str !j in
-      if c = expected
+      if Char.equal c expected
       then (
         (* char matches *)
         incr j;
@@ -181,7 +181,7 @@ module Find = struct
     while !j < pat_len && !i + !j < len do
       let c = String.get s (len - !i - !j - 1) in
       let expected = String.get pattern.str (String.length pattern.str - !j - 1) in
-      if c = expected
+      if Char.equal c expected
       then (
         (* char matches *)
         incr j;
@@ -280,7 +280,7 @@ let replace_at_ ~pos ~len ~by s =
   Buffer.contents b
 
 let replace ?(which=`All) ~sub ~by s =
-  if sub="" then invalid_arg "CCString.replace";
+  if is_empty sub then invalid_arg "CCString.replace";
   match which with
     | `Left ->
       let i = find ~sub s ~start:0 in
@@ -459,7 +459,7 @@ let edit_distance s1 s2 =
   then length s2
   else if length s2 = 0
   then length s1
-  else if s1 = s2
+  else if equal s1 s2
   then 0
   else begin
     (* distance vectors (v0=previous, v1=current) *)
@@ -778,14 +778,10 @@ let lowercase_ascii = map CCChar.lowercase_ascii
     #endif
 
 let equal_caseless s1 s2: bool =
-  let char_lower c =
-    if c >= 'A' && c <= 'Z'
-    then Char.unsafe_chr (Char. code c + 32)
-    else c
-  in
   String.length s1 = String.length s2 &&
   for_all2
-    (fun c1 c2 -> char_lower c1 = char_lower c2)
+    (fun c1 c2 ->
+       CCChar.equal (CCChar.lowercase_ascii c1) (CCChar.lowercase_ascii c2))
     s1 s2
 
 let pp buf s =
diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 13586ae7..30cb602c 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -513,7 +513,7 @@ let for_all p v =
     else p v.vec.(i) && check (i+1)
   in check 0
 
-let member ?(eq=(=)) x v =
+let member ~eq x v =
   exists (eq x) v
 
 let find_exn p v =
diff --git a/src/core/CCVector.mli b/src/core/CCVector.mli
index edb60897..b570905e 100644
--- a/src/core/CCVector.mli
+++ b/src/core/CCVector.mli
@@ -118,7 +118,7 @@ val shrink : ('a, rw) t -> int -> unit
 (** Shrink to the given size (remove elements above this size).
     Does nothing if the parameter is bigger than the current size. *)
 
-val member : ?eq:('a -> 'a -> bool) -> 'a -> ('a, _) t -> bool
+val member : eq:('a -> 'a -> bool) -> 'a -> ('a, _) t -> bool
 (** Is the element a member of the vector? *)
 
 val sort : ('a -> 'a -> int) -> ('a, _) t -> ('a, 'mut) t
diff --git a/src/data/CCCache.ml b/src/data/CCCache.ml
index ec956458..1ad77bdc 100644
--- a/src/data/CCCache.ml
+++ b/src/data/CCCache.ml
@@ -161,9 +161,13 @@ module Replacing = struct
       | Pair _
       | Empty -> raise Not_found
 
+  let is_empty = function
+    | Empty -> true
+    | Pair _ -> false
+
   let set c x y =
     let i = c.hash x mod Array.length c.arr in
-    if c.arr.(i) = Empty then c.c_size <- c.c_size + 1;
+    if is_empty c.arr.(i) then c.c_size <- c.c_size + 1;
     c.arr.(i) <- Pair (x,y)
 
   let iter c f =
diff --git a/src/data/CCDeque.ml b/src/data/CCDeque.ml
index 9453e464..00fe6a01 100644
--- a/src/data/CCDeque.ml
+++ b/src/data/CCDeque.ml
@@ -76,7 +76,7 @@ let is_zero_ n = match n.cell with
 
 let is_empty d =
   let res = d.size = 0 in
-  assert (res = is_zero_ d.cur);
+  assert (CCBool.equal res (is_zero_ d.cur));
   res
 
 let push_front d x =
@@ -377,7 +377,7 @@ let copy d =
   assert_equal ~cmp q q'
 *)
 
-let equal ?(eq=(=)) a b =
+let equal ~eq a b =
   let rec aux eq a b = match a() , b() with
     | None, None -> true
     | None, Some _
@@ -385,7 +385,7 @@ let equal ?(eq=(=)) a b =
     | Some x, Some y -> eq x y && aux eq a b
   in aux eq (to_gen a) (to_gen b)
 
-let compare ?(cmp=Pervasives.compare) a b =
+let compare ~cmp a b =
   let rec aux cmp a b = match a() , b() with
     | None, None -> 0
     | None, Some _ -> -1
@@ -412,4 +412,3 @@ let print pp_x out d =
        pp_x out x
     ) d;
   Format.fprintf out "}@]"
-
diff --git a/src/data/CCDeque.mli b/src/data/CCDeque.mli
index c0bde886..4571f63a 100644
--- a/src/data/CCDeque.mli
+++ b/src/data/CCDeque.mli
@@ -21,13 +21,13 @@ val clear : _ t -> unit
 val is_empty : 'a t -> bool
 (** Is the deque empty? *)
 
-val equal : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+val equal : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 (** [equal a b] checks whether [a] and [b] contain the same sequence of
     elements.
     @param eq comparison function for elements
     @since 0.13 *)
 
-val compare : ?cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
+val compare : cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
 (** [compare a b] compares lexicographically [a] and [b]
     @param cmp comparison function for elements
     @since 0.13 *)
diff --git a/src/data/CCFQueue.ml b/src/data/CCFQueue.ml
index de6848f1..e2bb56f1 100644
--- a/src/data/CCFQueue.ml
+++ b/src/data/CCFQueue.ml
@@ -34,10 +34,14 @@ let empty = Shallow Zero
 
 exception Empty
 
+let not_zero = function
+  | Zero -> false
+  | _ -> true
+
 let _single x = Shallow (One x)
 let _double x y = Shallow (Two (x,y))
 let _deep n hd middle tl =
-  assert (hd<>Zero && tl<>Zero);
+  assert (not_zero hd && not_zero tl);
   Deep (n, hd, middle, tl)
 
 let is_empty = function
diff --git a/src/data/CCHashTrie.ml b/src/data/CCHashTrie.ml
index 926d13c8..e21d08e1 100644
--- a/src/data/CCHashTrie.ml
+++ b/src/data/CCHashTrie.ml
@@ -291,6 +291,7 @@ module Make(Key : KEY)
     type t = private int
     val make : Key.t -> t
     val zero : t (* special "hash" *)
+    val equal : t -> t -> bool
     val is_0 : t -> bool
     val rem : t -> int (* [A.length_log] last bits *)
     val quotient : t -> t (* remove [A.length_log] last bits *)
@@ -298,6 +299,7 @@ module Make(Key : KEY)
     type t = int
     let make = Key.hash
     let zero = 0
+    let equal = (=)
     let is_0 h = h==0
     let rem h = h land (A.length - 1)
     let quotient h = h lsr A.length_log
@@ -407,14 +409,14 @@ module Make(Key : KEY)
   let rec add_ ~id k v ~h m = match m with
     | E -> S (h, k, v)
     | S (h', k', v') ->
-      if h=h'
+      if Hash.equal h h'
       then if Key.equal k k'
         then S (h, k, v)  (* replace *)
         else L (h, Cons (k, v, Cons (k', v', Nil)))
       else
         make_array_ ~id ~leaf:(Cons (k', v', Nil)) ~h_leaf:h' k v ~h
     | L (h', l) ->
-      if h=h'
+      if Hash.equal h h'
       then L (h, add_list_ k v l)
       else (* split into N *)
         make_array_ ~id ~leaf:l ~h_leaf:h' k v ~h
diff --git a/src/data/CCIntMap.ml b/src/data/CCIntMap.ml
index cf2e6f82..fb17ec00 100644
--- a/src/data/CCIntMap.ml
+++ b/src/data/CCIntMap.ml
@@ -11,6 +11,7 @@ module Bit : sig
   type t = private int
   val highest : int -> t
   val min_int : t
+  val equal : t -> t -> bool
   val is_0 : bit:t -> int -> bool
   val is_1 : bit:t -> int -> bool
   val mask : mask:t -> int -> int   (* zeroes the bit, puts all lower bits to 1 *)
@@ -20,6 +21,7 @@ end = struct
   type t = int
 
   let min_int = min_int
+  let equal = (=)
 
   let rec highest_bit_naive x m =
     if x=m then m
@@ -241,7 +243,7 @@ let rec equal ~eq a b = a==b || match a, b with
     | E, E -> true
     | L (ka, va), L (kb, vb) -> ka = kb && eq va vb
     | N (pa, sa, la, ra), N (pb, sb, lb, rb) ->
-      pa=pb && sa=sb && equal ~eq la lb && equal ~eq ra rb
+      pa=pb && Bit.equal sa sb && equal ~eq la lb && equal ~eq ra rb
     | E, _
     | N _, _
     | L _, _ -> false
@@ -295,7 +297,7 @@ let rec union f t1 t2 =
       (* insert k, v into o *)
       insert_ (fun ~old v -> f k old v) k v o
     | N (p1, m1, l1, r1), N (p2, m2, l2, r2) ->
-      if p1 = p2 && m1 = m2
+      if p1 = p2 && Bit.equal m1 m2
       then mk_node_ p1 m1 (union f l1 l2) (union f r1 r2)
       else if Bit.gt m1 m2 && is_prefix_ ~prefix:p1 p2 ~bit:m1
       then if Bit.is_0 p2 ~bit:m1
@@ -353,7 +355,7 @@ let rec inter f a b =
         with Not_found -> E
       end
     | N (p1, m1, l1, r1), N (p2, m2, l2, r2) ->
-      if p1 = p2 && m1 = m2
+      if p1 = p2 && Bit.equal m1 m2
       then mk_node_ p1 m1 (inter f l1 l2) (inter f r1 r2)
       else if Bit.gt m1 m2 && is_prefix_ ~prefix:p1 p2 ~bit:m1
       then if Bit.is_0 p2 ~bit:m1
diff --git a/src/data/CCMixmap.ml b/src/data/CCMixmap.ml
index 8c162a36..83dbdcbe 100644
--- a/src/data/CCMixmap.ml
+++ b/src/data/CCMixmap.ml
@@ -125,7 +125,7 @@ module Make(X : ORD) : S with type key = X.t = struct
 
   let mem ~inj x map =
     try
-      inj.get (M.find x map) <> None
+      CCOpt.is_some (inj.get (M.find x map))
     with Not_found -> false
 
   let iter_keys ~f map =
diff --git a/src/data/CCMixtbl.ml b/src/data/CCMixtbl.ml
index 8d1d9f73..7b8e8f8b 100644
--- a/src/data/CCMixtbl.ml
+++ b/src/data/CCMixtbl.ml
@@ -86,7 +86,7 @@ let copy tbl = Hashtbl.copy tbl
 
 let mem ~inj tbl x =
   try
-    inj.get (Hashtbl.find tbl x) <> None
+    CCOpt.is_some (inj.get (Hashtbl.find tbl x))
   with Not_found -> false
 
 (*$R
diff --git a/src/data/CCRAL.ml b/src/data/CCRAL.ml
index 5d9aa245..4783e3b4 100644
--- a/src/data/CCRAL.ml
+++ b/src/data/CCRAL.ml
@@ -371,7 +371,7 @@ let drop_while ~f l =
 
 let take_drop n l = take n l, drop n l
 
-let equal ?(eq=(=)) l1 l2 =
+let equal ~eq l1 l2 =
   let rec aux ~eq l1 l2 = match l1, l2 with
     | Nil, Nil -> true
     | Cons (size1, t1, l1'), Cons (size2, t2, l2') ->
@@ -543,7 +543,7 @@ let rec of_list_map ~f l = match l with
     let y = f x in
     cons y (of_list_map ~f l')
 
-let compare ?(cmp=Pervasives.compare) l1 l2 =
+let compare ~cmp l1 l2 =
   let rec cmp_gen ~cmp g1 g2 = match g1(), g2() with
     | None, None -> 0
     | Some _, None -> 1
diff --git a/src/data/CCRAL.mli b/src/data/CCRAL.mli
index 0e76eca3..70f7f12b 100644
--- a/src/data/CCRAL.mli
+++ b/src/data/CCRAL.mli
@@ -109,9 +109,9 @@ val rev_map : f:('a -> 'b) -> 'a t -> 'b t
 val rev : 'a t -> 'a t
 (** Reverse the list *)
 
-val equal : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+val equal : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 
-val compare : ?cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
+val compare : cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
 (** Lexicographic comparison *)
 
 (** {2 Utils} *)
diff --git a/src/data/CCSimple_queue.ml b/src/data/CCSimple_queue.ml
index ed9b639c..67e02bbb 100644
--- a/src/data/CCSimple_queue.ml
+++ b/src/data/CCSimple_queue.ml
@@ -23,7 +23,7 @@ let make_ hd tl = match hd with
   | [] -> {hd=List.rev tl; tl=[] }
   | _::_ -> {hd; tl; }
 
-let is_empty q = q.hd = []
+let is_empty q = CCList.is_empty q.hd
 
 let push x q = make_ q.hd (x :: q.tl)
 
@@ -31,7 +31,7 @@ let snoc q x = push x q
 
 let peek_exn q =
   match q.hd with
-    | [] -> assert (q.tl = []); invalid_arg "Queue.peek"
+    | [] -> assert (CCList.is_empty q.tl); invalid_arg "Queue.peek"
     | x::_ -> x
 
 let peek q = match q.hd with
@@ -40,7 +40,7 @@ let peek q = match q.hd with
 
 let pop_exn q =
   match q.hd with
-    | [] -> assert (q.tl = []); invalid_arg "Queue.peek"
+    | [] -> assert (CCList.is_empty q.tl); invalid_arg "Queue.peek"
     | x::hd' ->
       let q' = make_ hd' q.tl in
       x, q'
diff --git a/src/data/CCTrie.ml b/src/data/CCTrie.ml
index d7f8b9f7..b3799adf 100644
--- a/src/data/CCTrie.ml
+++ b/src/data/CCTrie.ml
@@ -19,6 +19,7 @@ module type WORD = sig
   val compare : char_ -> char_ -> int
   val to_seq : t -> char_ sequence
   val of_list : char_ list -> t
+  val equal : t -> t -> bool
 end
 
 module type S = sig
@@ -527,7 +528,7 @@ module Make(W : WORD)
     | Empty -> 0
     | Cons (_, t') -> size t'
     | Node (v, map) ->
-      let s = if v=None then 0 else 1 in
+      let s = if CCOpt.is_none v then 0 else 1 in
       M.fold
         (fun _ t' acc -> size t' + acc)
         map s
@@ -745,6 +746,7 @@ module MakeArray(X : ORDERED) = Make(struct
     let compare = X.compare
     let to_seq a k = Array.iter k a
     let of_list = Array.of_list
+    let equal = CCArray.equal (fun x y -> X.compare x y = 0)
   end)
 
 module MakeList(X : ORDERED) = Make(struct
@@ -753,6 +755,7 @@ module MakeList(X : ORDERED) = Make(struct
     let compare = X.compare
     let to_seq a k = List.iter k a
     let of_list l = l
+    let equal = CCList.equal (fun x y -> X.compare x y = 0)
   end)
 
 module String = Make(struct
@@ -764,4 +767,5 @@ module String = Make(struct
       let buf = Buffer.create (List.length l) in
       List.iter (fun c -> Buffer.add_char buf c) l;
       Buffer.contents buf
+    let equal = CCString.equal
   end)
diff --git a/src/data/CCTrie.mli b/src/data/CCTrie.mli
index 0cb34515..81f55d89 100644
--- a/src/data/CCTrie.mli
+++ b/src/data/CCTrie.mli
@@ -19,6 +19,7 @@ module type WORD = sig
   val compare : char_ -> char_ -> int
   val to_seq : t -> char_ sequence
   val of_list : char_ list -> t
+  val equal : t -> t -> bool
 end
 
 module type S = sig
diff --git a/src/iter/CCKTree.ml b/src/iter/CCKTree.ml
index eae5a29c..0d4489bb 100644
--- a/src/iter/CCKTree.ml
+++ b/src/iter/CCKTree.ml
@@ -141,13 +141,13 @@ module FQ = struct
 
   let empty = _make [] []
 
-  let is_empty q = q.hd = []
+  let is_empty q = CCList.is_empty q.hd
 
   let push q x = _make q.hd (x::q.tl)
 
   let pop_exn q =
     match q.hd with
-      | [] -> assert (q.tl = []); raise Empty
+      | [] -> assert (CCList.is_empty q.tl); raise Empty
       | x::hd' ->
         let q' = _make hd' q.tl in
         x, q'
diff --git a/src/sexp/CCSexp.ml b/src/sexp/CCSexp.ml
index 6e5d96a0..c781b4d3 100644
--- a/src/sexp/CCSexp.ml
+++ b/src/sexp/CCSexp.ml
@@ -13,7 +13,7 @@ type t = [
 ]
 type sexp = t
 
-let equal a b = a = b
+let equal a b = Pervasives.(=) a b
 
 let compare a b = Pervasives.compare a b
 
diff --git a/src/sexp/CCSexp_lex.mll b/src/sexp/CCSexp_lex.mll
index c67e66eb..250f6c31 100644
--- a/src/sexp/CCSexp_lex.mll
+++ b/src/sexp/CCSexp_lex.mll
@@ -22,7 +22,7 @@
 
   (* remove quotes + unescape *)
   let remove_quotes lexbuf s =
-    assert (s.[0] = '"' && s.[String.length s - 1] = '"');
+    assert (CCChar.equal s.[0] '"' && CCChar.equal s.[String.length s - 1] '"');
     let buf = Buffer.create (String.length s) in
     let st = ref Not_escaped in
     for i = 1 to String.length s-2 do
@@ -72,4 +72,3 @@ rule token = parse
   | string { ATOM (remove_quotes lexbuf (Lexing.lexeme lexbuf)) }
   | _ as c
     { error lexbuf (Printf.sprintf "lexing failed on char `%c`" c) }
-
diff --git a/src/threads/CCPool.ml b/src/threads/CCPool.ml
index 914461cc..ffa1ced4 100644
--- a/src/threads/CCPool.ml
+++ b/src/threads/CCPool.ml
@@ -314,11 +314,15 @@ module Make(P : PARAM) = struct
       | Run cell ->
         with_lock_ cell (fun cell -> cell.state)
 
+    let not_waiting = function
+      | Waiting -> false
+      | _ -> true
+
     let is_done = function
       | Return _
       | FailNow _ -> true
       | Run cell ->
-        with_lock_ cell (fun c -> c.state <> Waiting)
+        with_lock_ cell (fun c -> not_waiting c.state)
 
     (** {2 Combinators *)
 
diff --git a/src/threads/CCTimer.ml b/src/threads/CCTimer.ml
index f2c37cb8..8bd5a7d6 100644
--- a/src/threads/CCTimer.ml
+++ b/src/threads/CCTimer.ml
@@ -6,6 +6,8 @@
 type job =
   | Job : float * (unit -> 'a) -> job
 
+open CCFloat.Infix
+
 module TaskHeap = CCHeap.Make(struct
     type t = job
     let leq (Job(f1,_)) (Job (f2,_)) = f1 <= f2