28 Jan
2014
28 Jan
'14
9:40 p.m.
Hi Alvaro, 1. null . toList :: Foldable t => t a -> Bool 2. mappend, mplus, <|> are supposed to drop arguments that are mempty, mzero, empty respectively. There's no requirement to prefer the first argument, but that's what the MonadPlus Maybe instance does at least. -- Adam