mykhas/c4-problems.hs

## c4-problems.hs
sum' :: Num a => [a] -> a
sum' xs = case xs of
  []     -> 0
  (x:xs) -> x + sum' xs

initials :: String -> String -> String -- чому не працює String a => a -> a -> a
initials fn ln = [f] ++ " " ++ [l]
  where (f:_) = fn
        (l:_) = ln
	sum' :: Num a => [a] -> a
	sum' xs = case xs of
	[] -> 0
	(x:xs) -> x + sum' xs

	initials :: String -> String -> String -- чому не працює String a => a -> a -> a
	initials fn ln = [f] ++ " " ++ [l]
	where (f:_) = fn
	(l:_) = ln