Igloo (Ian Lynagh) allowed me kindly taking over maintainance on his printf library using template haskell written in 2003. I've updated it so that it compiles with ghc-6.8.2. You can get it from hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Printf-TH usage looks like this: {-# OPTIONS_GHC -XTemplateHaskell #-} ... import Language.Haskell.TH.Syntax import Text.Printf.TH (printf) ... putStrLn $ $(printf "Foo %H bar") (Just 5) putStrLn $ $(printf "%6d") 1 putStrLn $ $(printf "%6d") (-1) Short Explanation: $(printf "%d") will be replaced by a auto generated function taking an int etc Benefit: Wrong arg types or wrong printf arg count will result in compile time errors. Enjoy Marc Weber