___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.03, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package std ... linking ... done.
Prelude> :unset +s
Prelude> :unset +t
Prelude> -- first, clean up:
Prelude> :! rm -f *.hi *.o *~
Prelude> :! cp A1.hs A.hs
Prelude> 
Prelude> :load D
Ok, modules loaded: Main, C, B, A.
Main> 
Main> -- compile A & reload
Main> :! $HC $HC_OPTS -no-recomp -c A.hs
Main> :reload
Ok, modules loaded: Main, C, B, A.
Main> 
Main> B.g 42
85.0
Main> B.g 42
85.0
Main> B.g 42
85.0
Main> 
Main> -- swap A2 for A, compile & reload
Main> :! cp A2.hs A.hs
Main> :! $HC $HC_OPTS -no-recomp -c A.hs
Main> :reload
Ok, modules loaded: Main, C, B, A.
Main> -- the system should ignore the compiled version and compile its own.
Main> 
Main> B.g 42
46
Main> B.g 42
46
Main> B.g 42
46
Main> 
Main> -- pick up newly compiled A
Main> :load D
Ok, modules loaded: Main, C, B, A.
Main> 
Main> B.g 42
46
Main> B.g 42
46
Main> B.g 42
46
Main> 
Main> -- remove A.o: system should recompile A
Main> :! rm A.o
Main> :reload
Ok, modules loaded: Main, C, B, A.
Main> 
Main> B.g 42
46
Main> B.g 42
46
Main> B.g 42
46
Main> Leaving GHCi.