feat(vec): factor a bit of code for auxiliary functions in vectors

src/util/VecI32.ml

@@ -91,10 +91,11 @@ let[@inline] iteri ~f self =
     f i (Int32.to_int self.data.{i})
   done
 
-let[@inline] to_iter self k = iter ~f:k self
-
-let pp ppx out self =
-  Format.fprintf out "[@[";
-  iteri self ~f:(fun i x -> if i>0 then Format.fprintf out ",@ "; ppx out x);
-  Format.fprintf out "@]]"
-
+include Vec_sig.Make_extensions(struct
+    type nonrec elt = int
+    type nonrec t = t
+    let get = get
+    let size = size
+    let iter = iter
+    let iteri = iteri
+  end)

src/util/Vec_float.ml

@@ -78,11 +78,11 @@ let[@inline] iteri ~f self =
     f i self.data.{i}
   done
 
-let[@inline] to_iter self k = iter ~f:k self
-
-let pp ppx out self =
-  Format.fprintf out "[@[";
-  iteri self
-    ~f:(fun i x -> if i>0 then Format.fprintf out ",@ "; ppx out x);
-  Format.fprintf out "@]]"
-
+include Vec_sig.Make_extensions(struct
+    type nonrec elt = float
+    type nonrec t = t
+    let get = get
+    let size = size
+    let iter = iter
+    let iteri = iteri
+  end)

src/util/Vec_sig.ml

@@ -1,12 +1,22 @@
 
-module type S = sig
+(** Basics *)
+module type BASE_RO = sig
   type elt
   type t
 
-  val create : ?cap:int -> unit -> t
-
   val size : t -> int
 
+  val get : t -> int -> elt
+
+  val iter : f:(elt -> unit) -> t -> unit
+  val iteri : f:(int -> elt -> unit) -> t -> unit
+end
+
+module type BASE = sig
+  include BASE_RO
+
+  val create : ?cap:int -> unit -> t
+
   val clear : t -> unit
 
   val is_empty : t -> bool
@@ -21,16 +31,48 @@ module type S = sig
 
   val pop : t -> elt
 
-  val get : t -> int -> elt
-
   val set : t -> int -> elt -> unit
 
   val shrink : t -> int -> unit
+end
 
-  val iter : f:(elt -> unit) -> t -> unit
-  val iteri : f:(int -> elt -> unit) -> t -> unit
+module type EXTENSIONS = sig
+  type elt
+  type t
 
   val to_iter : t -> elt Iter.t
 
+  val to_array : t -> elt array
+
   val pp : elt CCFormat.printer -> t CCFormat.printer
 end
+
+module type S = sig
+  include BASE
+  include EXTENSIONS with type t := t and type elt := elt
+end
+
+module Make_extensions(B: BASE_RO)
+  : EXTENSIONS
+    with type t := B.t
+     and type elt := B.elt
+= struct
+  include B
+
+  let[@inline] to_iter self k = iter ~f:k self
+
+  let to_array self =
+    if size self = 0 then [||]
+    else (
+      let a = Array.make (size self) (get self 0) in
+      iteri self ~f:(Array.set a);
+      a
+    )
+
+  let pp ppx out self =
+    Format.fprintf out "[@[";
+    iteri self
+      ~f:(fun i x -> if i>0 then Format.fprintf out ",@ "; ppx out x);
+    Format.fprintf out "@]]"
+
+end