DDub questions

DDub answers

• Why does using PatternSynonyms trigger a non-exhaustive match warning?
• Haskell save recursive steps into a list
• Flip functor instance Haskell
• A way to generalize Haskell's Either type for arbitrarily many types?
• Is it possible to establish Coercible instances between custom types and standard library ones?
• Returning ‘Nothing’ if an indexed list traversal doesn’t match
• How to infer the type of the Scott encoded List constructor?
• About mapping through several nested functorial levels
• Apply constraint within constraint in Haskell
• Why is this implementation a bad instance of the Foldable Typeclass?