tasks a-s

Task/SEDOLs/OCaml/sedols.ocaml

@@ -0,0 +1,29 @@
+let char2value c =
+  assert (not (String.contains "AEIOU" c));
+  match c with
+     '0'..'9' -> int_of_char c - int_of_char '0'
+   | 'A'..'Z' -> int_of_char c - int_of_char 'A' + 10
+
+let sedolweight = [1;3;1;7;3;9]
+
+let explode s =
+  let result = ref [] in
+  String.iter (fun c -> result := c :: !result) s;
+  List.rev !result
+
+let checksum sedol =
+  let tmp = List.fold_left2 (fun sum ch weight -> sum + char2value ch * weight)
+              0 (explode sedol) sedolweight in
+    string_of_int ((10 - (tmp mod 10)) mod 10)
+
+List.iter (fun sedol -> print_endline (sedol ^ checksum sedol))
+  [ "710889";
+    "B0YBKJ";
+    "406566";
+    "B0YBLH";
+    "228276";
+    "B0YBKL";
+    "557910";
+    "B0YBKR";
+    "585284";
+    "B0YBKT" ]