Initial data commit

Task/Validate-International-Securities-Identification-Number/Elixir/validate-international-securities-identification-number.elixir

@@ -0,0 +1,19 @@
+isin? = fn str ->
+          if str =~ ~r/\A[A-Z]{2}[A-Z0-9]{9}\d\z/ do
+            String.codepoints(str)
+            |> Enum.map_join(&String.to_integer(&1, 36))
+            |> Luhn.valid?
+          else
+            false
+          end
+        end
+
+IO.puts "    ISIN        Valid?"
+~w(US0378331005
+   US0373831005
+   U50378331005
+   US03378331005
+   AU0000XVGZA3
+   AU0000VXGZA3
+   FR0000988040)
+|> Enum.each(&IO.puts "#{&1}\t#{isin?.(&1)}")