#5864: add a find operation to Set.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13211 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

Changes

@@ -56,6 +56,7 @@ Feature wishes:
 - PR#5769: Allow propagation of Sys.big_endian in native code
 - PR#5771: Add primitives for reading 2, 4, 8 bytes in strings and bigarrays
 - PR#5774: Add bswap primitives for amd64 and arm
+- PR#5864: Add a find operation to Set
 
 Tools:
 - OCamlbuild now features a bin_annot tag to generate .cmt files.

ocamlbuild/my_std.ml

@@ -62,7 +62,7 @@ module Set = struct
 
   module type S = sig
     include Set.S
-    val find : (elt -> bool) -> t -> elt
+    val find_elt : (elt -> bool) -> t -> elt
     val map : (elt -> elt) -> t -> t
     val of_list : elt list -> t
     val print : formatter -> t -> unit
@@ -71,7 +71,7 @@ module Set = struct
   module Make (M : OrderedTypePrintable) : S with type elt = M.t = struct
     include Set.Make(M)
     exception Found of elt
-    let find p set =
+    let find_elt p set =
       try
         iter begin fun elt ->
           if p elt then raise (Found elt)

ocamlbuild/rule.ml

@@ -161,7 +161,7 @@ let call builder r =
       begin match exists2 List.find Resource.Cache.resource_has_changed r.deps with
       | Some r -> (`cache_miss_changed_dep r, false)
       | _ ->
-        begin match exists2 Resources.find Resource.Cache.resource_has_changed dyndeps with
+        begin match exists2 Resources.find_elt Resource.Cache.resource_has_changed dyndeps with
         | Some r -> (`cache_miss_changed_dyn_dep r, false)
         | _ ->
             begin match cached_digest r with

ocamlbuild/signatures.mli

@@ -23,7 +23,7 @@ end
 
 module type SET = sig
   include Set.S
-  val find : (elt -> bool) -> t -> elt
+  val find_elt : (elt -> bool) -> t -> elt
   val map : (elt -> elt) -> t -> t
   val of_list : elt list -> t
   val print : Format.formatter -> t -> unit

stdlib/moreLabels.mli

@@ -159,6 +159,7 @@ module Set : sig
       val max_elt : t -> elt
       val choose : t -> elt
       val split: elt -> t -> t * bool * t
+      val find: elt -> t -> elt
     end
   module Make : functor (Ord : OrderedType) -> S with type elt = Ord.t
 end

stdlib/set.ml

@@ -47,6 +47,7 @@ module type S =
     val max_elt: t -> elt
     val choose: t -> elt
     val split: elt -> t -> t * bool * t
+    val find: elt -> t -> elt
   end
 
 module Make(Ord: OrderedType) =
@@ -348,4 +349,10 @@ module Make(Ord: OrderedType) =
 
     let choose = min_elt
 
+    let rec find x = function
+        Empty -> raise Not_found
+      | Node(l, v, r, _) ->
+          let c = Ord.compare x v in
+          if c = 0 then v
+          else find x (if c < 0 then l else r)
   end

stdlib/set.mli

@@ -143,6 +143,10 @@ module type S =
           strictly greater than [x];
           [present] is [false] if [s] contains no element equal to [x],
           or [true] if [s] contains an element equal to [x]. *)
+
+    val find: elt -> t -> elt
+    (** [find x s] returns the element of [s] equal to [x], or raise
+        [Not_found] if no such element exists. *)
   end
 (** Output signature of the functor {!Set.Make}. *)