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{-# 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
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