August 2020 1HaskellADay 1Liners

• 2020-08-31:
  #Haskell #BetterWithCurry #1Liner For:

  >>> :t Map.filterWithKey 
  Map.filterWithKey :: (k -> a -> Bool) -> Map k a -> Map k a

  we have this filtering function: \key _val -> not (Set.member key stoppers)

  _val is unused. Curry it away.

• 2020-08-28: 

  rmFront :: Set Char -> String -> String

  rmFront weirds str = dropWhile (flip Set.member weirds) str

  Simple currying questions: can this function-implementation be simplified with currying? Can it be simplified ... MORE? Answers: yes, and yes. Show your implementation.
  
  
• 2020-08-26: We have this: \info -> importBook info >>= return . (info,) There are way too many info-references. What's a better way to write this expression?
• Five solutions from @noaheasterly:
• runKleisli (id &&& Kleisli importBook)
• liftA2 (liftA2 (,)) return importBook
• liftA2 (fmap . (,)) id importBook
• traverse importBook . join (,)
• traverse importBook . (id &&& id)