Data update

Task/Variable-size-Get/OCaml/variable-size-get-1.ml

@@ -0,0 +1,25 @@
+(** The result is the size given in word.
+  The word size in octet can be found with (Sys.word_size / 8).
+  (The size of all the datas in OCaml is at least one word, even chars and bools.)
+*)
+let sizeof v =
+  let rec rec_size d r =
+    if List.memq r d then (1, d) else
+    if not(Obj.is_block r) then (1, r::d) else
+    if (Obj.tag r) = (Obj.double_tag) then (2, r::d) else
+    if (Obj.tag r) = (Obj.string_tag) then (Obj.size r, r::d) else
+    if (Obj.tag r) = (Obj.object_tag) ||
+       (Obj.tag r) = (Obj.closure_tag)
+    then invalid_arg "please only provide datas"
+    else
+      let len = Obj.size r in
+      let rec aux d sum i =
+        if i >= len then (sum, r::d) else
+        let this = Obj.field r i in
+        let this_size, d = rec_size d this in
+        aux d (sum + this_size) (i+1)
+      in
+      aux d (1) 0
+  in
+  fst(rec_size [] (Obj.repr v))
+;;