On the other hand, import Numeric main = do print (readDec "1.2" :: [(Integer,String)]) print (readSigned readDec "1.2" :: [(Integer,String)]) currently gives [(1,".2")] [] The behaviour of readDec is entirely as I would expect - the behaviour of readSigned is not. I think it is confusing that (readSigned readDec) and readDec give different results. As the errata maintainer of the Haskell'98 Report, I would be prepared to regard the current behaviour of readSigned as a Report bug, if there is consensus. I'm not sure whether Haskell'2010 has an errata maintainer. Regards, Malcolm On 17 Nov, 2010,at 09:00 AM, Lennart Augustsson <lennart@augustsson.net> wrote: The current behaviour is consistent with how Haskell tokenizes at the source level. I find this easy to remember, and I would be surprised if read behaved the way you suggest. -- Lennart On Tue, Nov 16, 2010 at 8:34 PM, Ian Lynagh <igloo@earth.li> wrote:
Proposal: Improve Read Integer http://hackage.haskell.org/trac/ghc/ticket/4500
Currently, according to H98, H2010, GHC and hugs, reads "1.2" :: [(Integer, String)] is [] whereas I would expect it to be [(1,".2")]
Patch: http://hackage.haskell.org/trac/ghc/attachment/ticket/4500/read-integer.dpat...
Suggested deadline: 1 Dec 2010.
Thanks Ian
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries