Print a newline as soon as the command starts to execute.
Only save again after stylish if necessary.
Use end-of-transmission for prompt
Echo extraneous output after prompt has been received

When the REPL spits out more stdout when no command is (ostensibly) in
progress, echo that output before the prompt.

Example case:

λ> forkIO (do threadDelay (1000*1000); putStrLn "yo")
ThreadId 37

yo
λ>

The "yo" is usually just lost in the ether. It also doesn't disturb
your prompt if you're typing in it.

@hvr @cmears might be interested.
Declare use of -insert-garbage
Strip out extraneous prompts
Dump complete output if zero compiler messages from cabal
Fix haskell-debug for recent prompt handling changes.
Strip newlines from haskell-process-do-type
Add sexp-based collapsing support in REPL

@hvr This is a little bit more lightweight, but probably more reliable
than my old approach. This is just simply looks for "nodeish" things
like { [ ( and then collapses them to their end by sexp-forward.

I was playing around with haskell-names which produces rather large
ADT values, so this makes inspecting it handy.
Popup error buffer instead of displaying them in the REPL
Fix spacing in type info regression (#264)
Fix error in haskell-interactive-mode completion (#263)
Add preliminary :present support

@hvr might be interested. If your data types are instances of Data,
the present package (http://hackage.haskell.org/package/present-0.0.0)
will print them to json or sexps in a breadth-first manner (allowing
for lazy expansion of infinite data types). I think this will be my
ultimate answer to the data inspection problem once I'm finished. =)
Support multiple directories in w3m-haddock
Indent alg-types with newlines and regular indentation
Much better list presentations
Handle compile messages from GHC that contain [TH]
Fix missing function reference
Fix to pass make check