A case in point.

[Alex Ferguson]

John Atwood:
> You have it right, except you need to 
>   1) explicitly type test,
>       test:: Reader [Char] Char


José Romildo Malaquias:
> > ---------------
> > test = do env <- ask
> >           if env == "choose a"
> >               then return 'a'
> >               else return 'b'
> > 
> > do_test = runReader test "choose a"

The very sort of thing I had in mind when I suggested some explicit
typings would be more concisely expressed by a type-ap.

Slán,
Alex.