barrucadu / both

This project is essentially abandonware!

This project is essentially abandonware!

I may respond to minor issues, like version bounds which need changing, but I won't be doing any significant work.

Offer to take over the package if you want any significant changes.

both

The Monoid instance for Maybe behaves like so:

instance Monoid a => Monoid (Maybe a) where
  mappend (Just x) (Just y) = Just $ x <> y
  mappend (Just x) Nothing  = Just x
  mappend Nothing  (Just y) = Just y
  mappend Nothing  Nothing  = Nothing

  mempty = Nothing

Both is a newtype wrapper around Maybe providing this instance:

instance Monoid a => Monoid (Both a) where
  mappend (Just x) (Just y) = Just $ x <> y
  mappend _ _ = Nothing

  mempty = Just mempty

Contributing

Bug reports, pull requests, and comments are very welcome!

Feel free to contact me on GitHub, through IRC (#haskell on libera.chat), or email ([e-mail]).