{-# LANGUAGE OverloadedStrings #-}

module Text.Fractions where

import Control.Applicative
import Data.Ratio ((%))
import Text.Trifecta

badFraction = "1/0"

alsoBad = "10"

shouldWork = "1/2"

shouldAlsoWork = "2/1"

parseFraction :: Parser Rational
parseFraction = do
    numerator <- decimal
    char '/'
    denominator <- decimal
    return (numerator % denominator)

virtuousFraction :: Parser Rational
virtuousFraction = do
    numerator <- decimal
    char '/'
    denominator <- decimal
    case denominator of
      0 -> fail "Denominator cannot be zero"
      _ -> return $ numerator % denominator