Parsing a stopwatch-like time string format in Elm

ParseStopwatch.elm

module ParseStopwatch exposing (..)

import Parser exposing (..)
import Parser.Char exposing (..)
import Parser.Number exposing (digit)
import Char
import Time exposing (..)


twoDigitInt : Parser Int
twoDigitInt =
    (map (\tens ones -> tens * 10 + ones)) digit `and` digit


threeDigitInt : Parser Int
threeDigitInt =
    (map (\hundreds tens ones -> hundreds * 100 + tens * 10 + ones)) digit `and` digit `and` digit


(**) x y = (toFloat x) * y

sumTimes : Int -> Int -> Int -> Int -> Time
sumTimes h m s ms =
    (h ** hour) + (m ** minute) + (s ** second) + (ms ** millisecond)

parseTime : Parser Time
parseTime =
    sumTimes
        `map` twoDigitInt
        <* symbol ':'
        `and` twoDigitInt
        <* symbol ':'
        `and` twoDigitInt
        <* symbol ','
        `and` threeDigitInt

-- parse parseTime "07:39:01,921" == Ok 27541921