Magicloud log parser

LogParser.hs

{-# LANGUAGE OverloadedStrings #-}

import Text.Regex.Applicative

(<:>) :: RE a b -> RE a [b] -> RE a [b]
(<:>) = liftA2 (:)
infixr 3 <:>

type Item = (String, String)

item :: String -> RE Char Item
item key = (,) key <$> few anySym

-- ${year}/${month}/${day} ${hour}:${minute} User ${username} runs command ${command}.
pattern :: RE Char [Item]
pattern =
    item "year" <* "/" <:> item "month" <* "/" <:> item "day" <* " " <:>
    item "hour" <* ":" <:> item "minute" <* " User " <:>
    item "username" <* " runs command " <:> item "command" <* "." <:>
    pure []

input :: String
input = "2019/04/17 17:27 User magicloud runs command ls."

output :: Maybe [Item]
output = match pattern input
-- Just [("year","2019"),("month","04"),("day","17"),("hour","17"),("minute","27"),("username","magicloud"),("command","ls")]