I am afraid little has changed since the last time this came up. You can now make a GHCJS app and run it in the Out pane. It can include DOM input elements and handle DOM events. StdIn input is still unsupported.
Check your indentation: maybe you're mixing tabs and spaces in a way that ghc interprets differently than leksah? I don't see another explanation for a parse error at print.
Generally Here's a editor/ide-agnostic solution to your problem: For language extensions, you can add this at the top of the source as a compiler pragma, which I prefer anyway: {-# LANGUAGE DeriveDataTypeable #-} instead of -XDeriveDataTypeable on the command line You can pass other command line options to GHC, like...
Thanks heaps for making this video, it makes it much easier to follow what is going on! I think the problem is that Haskell is really lazy. When you evaluated n at the very start of the debug session (before the video starts but you can see it in the...