Data update

Task/Exceptions/Pluto/exceptions.pluto

@@ -0,0 +1,22 @@
+local function get_day_no(day)
+    -- Throws an error if day is invalid.
+    return switch day:lower() do
+        case "monday"    -> 1
+        case "tuesday"   -> 2
+        case "wednesday" -> 3
+        case "thursday"  -> 4
+        case "friday"    -> 5
+        case "saturday"  -> 6
+        case "sunday"    -> 7
+        default          -> error($"'{day}' is not a valid day in English.")
+    end
+end
+
+for {"thursday", "jeudi"} as day do
+    local ok, res = pcall(get_day_no, day)
+    if ok then
+        print($"'{day}' is day number {res}")
+    else
+        print(res)
+    end
+end