style(list): move sorted_mem up

src/core/CCList.ml

@@ -722,6 +722,19 @@ let map_product_l f l =
     cmp_lii_unord (cartesian_product l) (map_product_l CCFun.id l))
 *)
 
+let rec sorted_mem ~cmp x l = match l with
+  | [] -> false
+  | y :: tail ->
+    match cmp x y with
+      | 0 -> true
+      | n when n<0 -> false
+      | _ -> (sorted_mem[@tailcall]) ~cmp x tail
+
+(*$Q
+  Q.(pair small_int (list small_int)) (fun (x,l) -> \
+    sorted_mem ~cmp:CCInt.compare x (List.sort CCInt.compare l) = mem ~eq:CCInt.equal x l)
+*)
+
 let sorted_merge ~cmp l1 l2 =
   let rec recurse cmp acc l1 l2 = match l1,l2 with
     | [], _ -> List.rev_append acc l2
@@ -797,19 +810,6 @@ let is_sorted ~cmp l =
     is_sorted ~cmp:CCInt.compare (List.sort Stdlib.compare l))
 *)
 
-let rec sorted_mem ~cmp x l = match l with
-  | [] -> false
-  | y :: tail ->
-    match cmp x y with
-      | 0 -> true
-      | n when n<0 -> false
-      | _ -> (sorted_mem[@tailcall]) ~cmp x tail
-
-(*$Q
-  Q.(pair small_int (list small_int)) (fun (x,l) -> \
-    sorted_mem ~cmp:CCInt.compare x (List.sort CCInt.compare l) = mem ~eq:CCInt.equal 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]

src/core/CCList.mli

@@ -497,6 +497,11 @@ val all_ok : ('a, 'err) result t -> ('a t, 'err) result
     @since 1.3, but only
     @since 2.2 with labels *)
 
+val sorted_mem : cmp:('a -> 'a -> int) -> 'a -> 'a list -> bool
+(** [sorted_mem ~cmp x l] and [mem x l] give the same result for any sorted list [l],
+    but potentially more efficiently.
+    @since NEXT_RELEASE *)
+
 val sorted_merge : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** [sorted_merge ~cmp l1 l2] merges elements from both sorted list using
     the given comparison function [cmp]. *)
@@ -535,10 +540,6 @@ val is_sorted : cmp:('a -> 'a -> int) -> 'a list -> bool
     @param cmp the comparison function.
     @since 0.17 *)
 
-val sorted_mem : cmp:('a -> 'a -> int) -> 'a -> 'a list -> bool
-(** Suppose the list [l] is sorted. [sorted_mem x l] is [true] iff [x] is equal to an element of [l].
-    @since NEXT_RELEASE *)
-
 val sorted_insert : cmp:('a -> 'a -> int) -> ?uniq:bool -> 'a -> 'a list -> 'a list
 (** [sorted_insert ~cmp ?uniq x l] inserts [x] into [l] such that, if [l] was sorted,
     then [sorted_insert x l] is sorted too.

src/core/CCListLabels.mli

@@ -500,6 +500,11 @@ val all_ok : ('a, 'err) result t -> ('a t, 'err) result
     @since 1.3, but only
     @since 2.2 with labels *)
 
+val sorted_mem : cmp:(('a -> 'a -> int) [@keep_label]) -> 'a -> 'a list -> bool
+(** [sorted_mem ~cmp x l] and [mem x l] give the same result for any sorted list [l],
+    but potentially more efficiently.
+    @since NEXT_RELEASE *)
+
 val sorted_merge : cmp:(('a -> 'a -> int) [@keep_label]) -> 'a list -> 'a list -> 'a list
 (** [sorted_merge ~cmp l1 l2] merges elements from both sorted list using
     the given comparison function [cmp]. *)
@@ -538,10 +543,6 @@ val is_sorted : cmp:(('a -> 'a -> int) [@keep_label]) -> 'a list -> bool
     @param cmp the comparison function.
     @since 0.17 *)
 
-val sorted_mem : cmp:(('a -> 'a -> int) [@keep_label]) -> 'a -> 'a list -> bool
-(** Suppose the list [l] is sorted. [sorted_mem x l] is [true] iff [x] is equal to an element of [l].
-    @since NEXT_RELEASE *)
-
 val sorted_insert : cmp:(('a -> 'a -> int) [@keep_label]) -> ?uniq:bool -> 'a -> 'a list -> 'a list
 (** [sorted_insert ~cmp ?uniq x l] inserts [x] into [l] such that, if [l] was sorted,
     then [sorted_insert x l] is sorted too.