You want:
  return ()

(Look at the type of putStrLn.)

On Mon, Jan 21, 2019 at 2:49 PM Damien Mattei <damien.mattei@gmail.com> wrote:
i have this in a Monad IO:

 forM_ fltrdNamesBDs $ \(name,bdSidonie,bdWDS) ->
          if (bdWDS /= bdSidonie)
          then
             putStrLn $  name ++ " " ++ (show (bdSidonie :: Maybe Float)) ++ " " ++ show (bdWDS :: Maybe Float) ++ " " ++ show (bdWDS == bdSidonie)
          else
             putStr ""

is there a way to remove the silly putStr "" that output an empty string, i tried with when.... but as when return Nothing in case of False it fails to compile

_______________________________________________
Haskell-Cafe mailing list
To (un)subscribe, modify options or view archives go to:
http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
Only members subscribed via the mailman list are allowed to post.


--
brandon s allbery kf8nh
allbery.b@gmail.com