On 22 April 2011 21:26, Henning Thielemann <lemming@henning-thielemann.de> wrote:
In idiomatic Haskell you would write

case userList of
  Nothing -> Nothing
  Just plainUserList =
     let user = findUser "bob" plainUserList
     ...

since (userList /= Nothing) requires an Eq instance without need and it requires fromJust. Or was there an educational purpose to write it with (/= Nothing) ?
 
Educational; it was just to make it look like and have similar meaning (as I perceived it) to the Fantom code. (I'd never write code like this; I use case analysis and avoid if.)