Data commit

Task/Currency/Haskell/currency.hs

@@ -0,0 +1,20 @@
+import Data.Fixed
+import Text.Printf
+
+type Percent = Centi
+type Dollars = Centi
+
+tax :: Percent -> Dollars -> Dollars
+tax rate = MkFixed . round . (rate *)
+
+printAmount :: String -> Dollars -> IO ()
+printAmount name = printf "%-10s %20s\n" name . showFixed False
+
+main :: IO ()
+main = do
+  let subtotal = 4000000000000000 * 5.50 + 2 * 2.86
+      tx       = tax 7.65 subtotal
+      total    = subtotal + tx
+  printAmount "Subtotal" subtotal
+  printAmount "Tax"      tx
+  printAmount "Total"    total