[Haskell-cafe] Data.Time.Calendar.Day does not seem to have an instance for Read
C K Kashyap
ckkashyap at gmail.com
Thu Mar 17 07:30:06 CET 2011
> On Thu, Mar 17, 2011 at 12:30 AM, C K Kashyap <ckkashyap at gmail.com> wrote:
> > Hi,
> > I was wondering if this is a defect -
> > Prelude> import Data.Time.Calendar
> > Prelude Data.Time.Calendar> read "2011-10-10" :: Day
> > <interactive>:1:1:
> > No instance for (Read Day)
> > arising from a use of `read'
> > Possible fix: add an instance declaration for (Read Day)
> > In the expression: read "2011-10-10" :: Day
> > In an equation for `it': it = read "2011-10-10" :: Day
> > Prelude Data.Time.Calendar>
> I see the same problem with GHC 7.0.2, time-22.214.171.124.
> Does it work if you use it in a Haskell source file, instead of GHCi?
Nope, even compiling with ghc causes the error.
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