-- | Runs the given printer iff the specified PP option is True.
whenOpt :: (PPOpts -> Bool) -> PP () -> PP ()
whenOpt f p = getOpt f >>= \x -> when x p
whenOpt :: (PPOpts -> Bool) -> PP () -> PP ()
whenOpt f p = getOpt f >>= \x -> when x p
whenOpt f p = getOpt f >>= \x -> when x p