    {- arch-tag: Maybe utilities
    Copyright (c) 2005-2011 John Goerzen <jgoerzen@complete.org>

    All rights reserved.

    For license and copyright information, see the file LICENSE
    -}

    {- |
       Module     : Data.Maybe.Utils
       Copyright  : Copyright (C) 2005-2011 John Goerzen
       License    : BSD3

       Maintainer : John Goerzen <jgoerzen@complete.org>
       Stability  : provisional
       Portability: portable

    Utilities for working with the Either data type

    -}
    module Data.Maybe.Utils
        (
         forceMaybe, forceMaybeMsg
    ) where

    {- | Pulls a Just value out of a Maybe value.  If the Maybe value is
    Nothing, raises an exception with error. -}
    forceMaybe :: Maybe a -> a
    forceMaybe = forceMaybeMsg "forceMaybe: Got Nothing"

    {- | Like 'forceMaybe', but lets you customize the error message raised if
    Nothing is supplied. -}
    forceMaybeMsg :: String -> Maybe a -> a
    forceMaybeMsg msg Nothing = error msg
    forceMaybeMsg _ (Just x) = x