31 May
2020
31 May
'20
8:06 a.m.
I mean, shouldn't there be a guard? instance (Integral a, Read a) => ReadPrec (Ratio a) where readPrec = parens . prec 7 $ do n <- step readPrec lift (expect (Symbol "%")) d <- step readPrec *guard (**0 /= d)* return (n % d) 2020년 5월 31일 (일) 오후 12:13, Dannyu NDos <ndospark320@gmail.com>님이 작성:
Shouldn't the parser be pfail rather than throwing an error?