[maikklein]

He wrote

  either :: (LoginError -> Text) -> (Text -> Text) -> (Either LoginError Text -> Text)

But shouldn't it be

  either :: (LoginError -> Text) -> (Text -> Text) -> (Either LoginError Text) -> Text

[hesselink]

In Haskell, `a -> b -> c` and `a -> (b -> c)` are the same types.