Re: Proposal: Improve Read Integer

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 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 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

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