Improved code CIS 194 week 2

Main.hs

{-# OPTIONS_GHC -Wall #-}
module Main where

import Log

parse :: String -> [LogMessage]
parse xs = map parseMessage $ lines xs

parseMessage :: String -> LogMessage
parseMessage = createLog . words

createLog :: [String] -> LogMessage
createLog ("E":err:t:m) = LogMessage (Error (read err)) ( read t ) (unwords m )
createLog ("I":t:m) = LogMessage Info ( read t ) (unwords m )
createLog ("W":t:m) = LogMessage Warning ( read t ) (unwords m )
createLog xs = Unknown (unwords xs )

insert :: LogMessage -> MessageTree -> MessageTree
insert logM Leaf = Node Leaf logM Leaf
insert logM (Node l m r)
 |getTimestamp logM > getTimestamp m = Node l m ( insert logM r )
 |getTimestamp logM < getTimestamp m = Node ( insert logM l ) m r
 |otherwise = Node l m r

getTimestamp :: LogMessage -> TimeStamp
getTimestamp (Unknown _) = error "Unknown logmessage dont have timestamp"
getTimestamp (LogMessage _ x _) = x

build :: [LogMessage] -> MessageTree
build = foldr insert Leaf

inOrder :: MessageTree -> [LogMessage]
inOrder Leaf = []
inOrder (Node l m r) = inOrder l ++ [m] ++ inOrder r

whatWentWrong :: [LogMessage] -> [String]
whatWentWrong = map getMessageFromLog . filter (\x -> isError x && getErrorIntensity x > 50 )

isError :: LogMessage -> Bool
isError (LogMessage (Error _) _ _) = True
isError _ = False

getMessageFromLog :: LogMessage -> String
getMessageFromLog (Unknown _) = error "Unknown dont have message"
getMessageFromLog (LogMessage _ _ m) = m

getErrorIntensity :: LogMessage -> Int
getErrorIntensity (LogMessage (Error x) _ _) = x
getErrorIntensity _ = error "this function only works with Error type"

sortLog :: [LogMessage] -> [LogMessage]
sortLog = inOrder . build