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module LogParser where
import Control.Applicative
import Data.Time
import Test.QuickCheck
import Text.Trifecta
-- 5. Write a parser for a log file format and sum the time spent in
-- each activity. Additionally, provide an alternative aggregation
-- of the data that provides average time spent per activity per day.
-- The format supports the use of comments which your parser
-- will have to ignore. The # characters followed by a date mark
-- the beginning of a particular day.
--
-- You are to derive a reasonable datatype for representing this
-- data yourself. For bonus points, make this bi-directional by
-- making a Show representation for the datatype which matches
-- the format you are parsing. Then write a generator for this data
-- using QuickCheck’s Gen and see if you can break your parser
-- with QuickCheck.
data Statement = Statement TimeOfDay String deriving Eq
data LogEntry = LogEntry Day [Statement] deriving Eq
newtype Log = Log { getLog :: [LogEntry] }
instance Show Statement where
show (Statement x y) = (formatTime defaultTimeLocale "%R" x) ++ " " ++ y
instance Show LogEntry where
show (LogEntry x y) = "# " ++ (show x) ++ "\n"
++ (foldl (\acc v -> acc ++ (show v) ++ "\n") "" y)
instance Show Log where
show (Log y) = (foldl (\acc v -> acc ++ (show v) ++ "\n") "" y)
instance Arbitrary Statement where
arbitrary = do
h <- choose (0, 23)
m <- choose (0, 59)
text <- listOf1 $ elements ['.'..'~']
return $ Statement (TimeOfDay h m 0) text
instance Arbitrary LogEntry where
arbitrary = do
day <- arbitrary
statements <- arbitrary
return $ LogEntry (ModifiedJulianDay day) statements
skipEOL :: Parser ()
skipEOL = skipMany (oneOf "\n")
skipComments :: Parser ()
skipComments =
skipMany (do _ <- char '-'
_ <- char '-'
skipMany (noneOf "\n")
skipEOL)
parseStatement :: Parser Statement
parseStatement = do
h <- integer
_ <- char ':'
m <- integer
text <- manyTill anyChar (try (string "--") <|> (string "\n") <|> (eof >> return ""))
skipComments
skipEOL
return $ Statement (TimeOfDay (fromIntegral h) (fromIntegral m) 0) text
parseLogEntry :: Parser LogEntry
parseLogEntry = do
_ <- string "# "
y <- integer
_ <- char '-'
m <- integer
_ <- char '-'
d <- integer
skipComments
skipEOL
statements <- many parseStatement
return $ LogEntry (fromGregorian (fromIntegral y) (fromIntegral m) (fromIntegral d)) statements
parseLog :: Parser Log
parseLog = Log <$> many parseLogEntry
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