:l shell.hs
:def shell (\s -> do shell s; return "")
:l

:shell cp Defer03_before.hs Defer03.hs

-- Test :load! and :reload!

-- main is independent of functions with type errors and thus
-- executable after load
-- warnings on type errors are emitted nevertheless
:load!   Defer03

-- fails to load module due to type errors
:load    Defer03

-- succeeds again to load module
:reload!

-- also succeeds, because the module has not been changed since load
:reload

-- now, after modifying, reloading should fail
:shell echo "-- an extra comment so that the hash changes" >> Defer03.hs
:reload

-- using the deferred version of reload, loading should succeed again
:reload!

:shell rm Defer03.hs