• Iustin Pop's avatar
    Change type of program options to 'IO [Options]' · d66aa238
    Iustin Pop authored
    Some options have defaults that depend on the environment, and we
    could handle these in two ways:
    - use a place-holder value (e.g. data X a = Default | Custom a) that
      is later read from the environment
    - move the options list to IO monad, where it can read the
      environment, etc.
    The second option allows also displaying the actual defaults in the
    `--help' output, even though it's not as nice, so I went with it.
    This patch only changes the option types, without actually changing
    any options yet.
    Signed-off-by: default avatarIustin Pop <iustin@google.com>
    Reviewed-by: default avatarHelga Velroyen <helgav@google.com>
Hail.hs 2.76 KB