Does someone knows what this code does?I know its validating the given year but I didn't really get the idea of the whole process.
tempYear <- getLine
case reads tempYear :: [(Integer, String)] of
[(n, "")] -> do let year = read tempYear :: Int
I guess the case reads is there to deal with the case in which getLine does not return a proper number. reads returns a list of possible answers. If the tempYear were to start with a non-digit the empty list would be returned. If there was some other letter or something like that in the string, then the number up to that letter would be n. But the second value in the tuple would not be the empty string but the unparsed rest of the string.
However, I don't know why he would read an Integer first and then an Int. If the two types were equal, n would also be equal to year.
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