import List
{-
data Line = Line Int String deriving Show
-}
data Line = Line { number :: Int, string :: String } deriving Show
myLines :: [Line]
myLines = [ (Line 4 "4th line"),
(Line 1 "first line"),
(Line 5 "5th line"),
(Line 3 "3rd line"),
(Line 2 "second line") ]
sortLines :: [Line] -> [Line]
sortLines = sortBy (\a b -> number a `compare` number b)
main = do
print $ Line 1 "first line"
print $ myLines
print $ sortLines myLines