On Tue, 28 Aug 2001, Patrik Jansson wrote: (snip)
Prelude> reads "123.45a" :: [(Float,String)] [(123.45,"a")] Prelude> reads "123a.45" :: [(Float,String)] [(123.0,"a.45")] Prelude> reads "a123.45" :: [(Float,String)] [] Prelude> reads "Infinity" :: [(Float,String)] *** Exception: Ratio.%: zero denominator
On 28 Aug 2001 kahl@heraklit.informatik.unibw-muenchen.de wrote:
You might want to wrap it in something like the following:
read' :: Read a => String -> Maybe a read' s = case reads s of ((a,[]):_) -> Just a _ -> Nothing
Thanks very much for this, too. That is also most useful. This is a great list - I'll try not to abuse everyone's willingness to help! (-: I'm still trying to understand Chris Angus' suggestion, but it's just a matter of me spending enough time on it. I assume the Infinity problem above is just a bug that isn't fixed in that GHC. -- Mark