Adding to_string (#270)

* add `CCArray.to_string`
* add `CCArrayLabels.to_string`
* add `CCList.to_string`
* add `CCListLabels.to_string`
* add `CCChar.to_string`
* add `CCPair.to_string`
* add `CCHeap.to_string`
* add `CCSet.to_string`
* add `CCVector.to_string`

src/core/CCArray.ml

@@ -540,6 +540,18 @@ let pp_i ?(sep=", ") pp_item out a =
     pp_item k out a.(k)
   done
 
+let to_string ?(sep=", ") item_to_string a =
+  Array.to_list a
+  |> List.map item_to_string
+  |> String.concat sep
+
+(*$= to_string & ~printer:(fun s -> s)
+  (to_string string_of_int [|1;2;3;4;5;6|]) "1, 2, 3, 4, 5, 6"
+  (to_string string_of_int [||]) ""
+  (to_string ~sep:" " string_of_int [|1;2;3;4;5;6|]) "1 2 3 4 5 6"
+  (to_string string_of_int [|1|]) "1"
+*)
+
 let to_seq a k = iter k a
 
 let to_gen a =

src/core/CCArray.mli

@@ -244,6 +244,11 @@ val random_choose : 'a t -> 'a random_gen
 (** [random_choose a rs] randomly chooses an element of [a].
     @raise Not_found if the array/slice is empty. *)
 
+val to_string : ?sep:string -> ('a -> string) -> 'a array -> string
+(** [to_string ~sep item_to_string a] print [a] to a string using [sep] as a separator
+    between elements of [a].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** [to_seq a] returns a [sequence] of the elements of an array [a].
     The input array [a] is shared with the sequence and modification of it will result

src/core/CCArrayLabels.mli

@@ -245,6 +245,11 @@ val random_choose : 'a t -> 'a random_gen
 (** [random_choose a rs] randomly chooses an element of [a].
     @raise Not_found if the array/slice is empty. *)
 
+val to_string : ?sep:string -> ('a -> string) -> 'a array -> string
+(** [to_string ~sep item_to_string a] print [a] to a string using [sep] as a separator
+    between elements of [a].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** [to_seq a] returns a [sequence] of the elements of an array [a].
     The input array [a] is shared with the sequence and modification of it will result

src/core/CCChar.ml

@@ -16,6 +16,12 @@ let of_int_exn = Char.chr
 let of_int c = try Some (of_int_exn c) with _ -> None
 let to_int = Char.code
 
+let to_string c = String.make 1 c
+
+(*$Q to_string
+  (Q.string_of_size (Q.Gen.return 1)) (fun s -> to_string s.[0] = s)
+*)
+
 let lowercase_ascii = function
   | 'A'..'Z' as c -> Char.unsafe_chr (Char.code c + 32)
   | c -> c

src/core/CCChar.mli

@@ -40,6 +40,10 @@ val to_int : t -> int
     Return the ASCII code of the argument.
     @since 1.0 *)
 
+val to_string : t -> string
+(** [to_string c] return a string containing [c]
+    @since NEXT_RELEASE *)
+
 val pp_buf : Buffer.t -> t -> unit
 (** Renamed from [pp] since 2.0. *)
 

src/core/CCHeap.ml

@@ -202,6 +202,10 @@ module type S = sig
   val to_tree : t -> elt ktree
   (** Return a [ktree] of the elements of the heap. *)
 
+  val to_string : ?sep:string -> (elt -> string) -> t -> string
+  (**  Print the heap in a string
+       @since NEXT_RELEASE *)
+
   val pp : ?sep:string -> elt printer -> t printer
   (** @since 0.16
       Renamed from {!print} @since 2.0 *)
@@ -404,6 +408,22 @@ module Make(E : PARTIAL_ORD) : S with type elt = E.t = struct
     | E -> `Nil
     | N (_, x, l, r) -> `Node(x, [to_tree l; to_tree r])
 
+  let to_string ?(sep=",") elt_to_string h =
+    to_list_sorted h
+    |> 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 ?(sep=",") pp_elt out h =
     let first=ref true in
     iter

src/core/CCHeap.mli

@@ -142,6 +142,10 @@ module type S = sig
   val to_tree : t -> elt ktree
   (** Return a [ktree] of the elements of the heap. *)
 
+  val to_string : ?sep:string -> (elt -> string) -> t -> string
+  (**  Print the heap in a string
+       @since NEXT_RELEASE *)
+
   val pp : ?sep:string -> elt printer -> t printer
   (** Printer.
       Renamed from {!print} since 2.0

src/core/CCList.ml

@@ -1649,6 +1649,18 @@ let random_choose l = match l with
 
 let random_sequence l st = map (fun g -> g st) l
 
+let to_string ?(start="") ?(stop="") ?(sep=", ") item_to_string l =
+  let l = List.map item_to_string l in
+  start ^ (String.concat sep l) ^ stop
+
+(*$= to_string & ~printer:(fun s -> s)
+  (to_string string_of_int []) ""
+  (to_string ~start:"[" ~stop:"]" string_of_int []) "[]"
+  (to_string ~start:"[" ~stop:"]" string_of_int [1]) "[1]"
+  (to_string ~start:"[" ~stop:"]" string_of_int [1;2;3;4]) "[1, 2, 3, 4]"
+  (to_string ~sep:" " string_of_int [1;2;3;4]) "1 2 3 4"
+*)
+
 let to_seq l k = List.iter k l
 let of_seq seq =
   let l = ref [] in

src/core/CCList.mli

@@ -685,6 +685,12 @@ val random_choose : 'a t -> 'a random_gen
 
 val random_sequence : 'a random_gen t -> 'a t random_gen
 
+val to_string : ?start:string -> ?stop:string -> ?sep:string ->
+  ('a -> string) -> 'a t -> string
+(** [to_string ~start ~stop ~sep item_to_string l] print [l] to a string using
+    [sep] as a separator between elements of [l].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** Return a [sequence] of the elements of the list. *)
 

src/core/CCListLabels.mli

@@ -683,6 +683,12 @@ val random_choose : 'a t -> 'a random_gen
 
 val random_sequence : 'a random_gen t -> 'a t random_gen
 
+val to_string : ?start:string -> ?stop:string -> ?sep:string ->
+  ('a -> string) -> 'a t -> string
+(** [to_string ~start ~stop ~sep item_to_string l] print [l] to a string using
+    [sep] as a separator between elements of [l].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** Return a [sequence] of the elements of the list. *)
 

src/core/CCPair.ml

@@ -42,6 +42,8 @@ let compare f g (x1,y1) (x2,y2) =
   let c = f x1 x2 in
   if c <> 0 then c else g y1 y2
 
+let to_string ?(sep=", ") a_to_string b_to_string (x,y) =
+  Printf.sprintf "%s%s%s" (a_to_string x) sep (b_to_string y)
 
 type 'a printer = Format.formatter -> 'a -> unit
 

src/core/CCPair.mli

@@ -67,6 +67,10 @@ val equal : ('a -> 'a -> bool) -> ('b -> 'b -> bool) -> ('a * 'b) -> ('a * 'b) -
 
 val compare : ('a -> 'a -> int) -> ('b -> 'b -> int) -> ('a * 'b) -> ('a * 'b) -> int
 
+val to_string : ?sep:string -> ('a -> string) -> ('b -> string) -> ('a * 'b) -> string
+(** Print tuple in a string
+    @since NEXT_RELEASE *)
+
 type 'a printer = Format.formatter -> 'a -> unit
 
 val pp : ?sep:string -> 'a printer -> 'b printer -> ('a * 'b) printer

src/core/CCSet.ml

@@ -8,6 +8,13 @@ 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
 
@@ -59,6 +66,12 @@ module type S = sig
 
   val to_list : t -> elt list
 
+  val to_string :
+    ?start:string -> ?stop:string -> ?sep:string ->
+    (elt -> string) -> t -> string
+  (**  Print the set in a string
+       @since NEXT_RELEASE *)
+
   val pp :
     ?start:string -> ?stop:string -> ?sep:string ->
     elt printer -> t printer
@@ -135,6 +148,26 @@ module Make(O : Map.OrderedType) = struct
 
   let to_list = elements
 
+  let to_string ?(start="") ?(stop="") ?(sep=",") elt_to_string h =
+    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 ?(start="") ?(stop="") ?(sep=", ") pp_x fmt m =
     Format.pp_print_string fmt start;
     let first = ref true in

src/core/CCSet.mli

@@ -65,6 +65,12 @@ module type S = sig
   val to_list : t -> elt list
   (** [to_list t] converts the set [t] to a list of the elements. *)
 
+  val to_string :
+    ?start:string -> ?stop:string -> ?sep:string ->
+    (elt -> string) -> t -> string
+  (**  Print the set in a string
+       @since NEXT_RELEASE *)
+
   val pp :
     ?start:string -> ?stop:string -> ?sep:string ->
     elt printer -> t printer

src/core/CCVector.ml

@@ -942,6 +942,9 @@ let to_klist v =
     else `Cons (v.vec.(i), aux (i+1))
   in aux 0
 
+let to_string ?(start="") ?(stop="") ?(sep=", ") item_to_string v =
+  to_list v |> CCList.to_string ~start ~stop ~sep item_to_string
+
 let pp ?(start="") ?(stop="") ?(sep=", ") pp_item fmt v =
   Format.pp_print_string fmt start;
   iteri

src/core/CCVector.mli

@@ -287,5 +287,11 @@ val to_klist : ('a,_) t -> 'a klist
 val of_gen : ?init:('a, rw) t -> 'a gen -> ('a, rw) t
 val to_gen : ('a,_) t -> 'a gen
 
+val to_string :
+  ?start:string -> ?stop:string -> ?sep:string ->
+  ('a -> string) -> ('a,_) t -> string
+(**  Print the vector in a string
+     @since NEXT_RELEASE *)
+
 val pp : ?start:string -> ?stop:string -> ?sep:string ->
   'a printer -> ('a,_) t printer