___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.01, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package std ... linking ... done.
Prelude> :unset +s
Prelude> -- first, tidy up:
Prelude> :! rm -f *.hi *.o *~
Prelude> :! cp D1.hs D.hs
Prelude> 
Prelude> -- load the program (all interpreted)
Prelude> :load A
Ok, modules loaded: Main, B, C, D.
Main> 
Main> -- reloading should do nothing
Main> :reload
Ok, modules loaded: Main, B, C, D.
Main> 
Main> -- make sure `main' works
Main> main
"hello world84"
Main> 
Main> -- touch a module + recompile
Main> :! sleep 1
Main> :! touch C.hs
Main> :reload
Ok, modules loaded: Main, B, C, D.
Main> 
Main> -- make sure `main' still works
Main> main
"hello world84"
Main> 
Main> -- compile D & reload
Main> :! $HC $HC_OPTS -no-recomp -c D.hs
Main> :reload
Ok, modules loaded: Main, B, C, D.
Main> main
"hello world84"
Main> 
Main> -- change D, recompile & reload
Main> :! cp D2.hs D.hs
Main> :! $HC $HC_OPTS -no-recomp -c D.hs
Main> :reload
Ok, modules loaded: Main, B, C, D.
Main> :load A
Ok, modules loaded: Main, B, C, D.
Main> 
Main> -- make sure we're picking up the new D, via B
Main> :module B
B> g 42
44
B> Leaving GHCi.