On Thu, Mar 17, 2011 at 07:30, C K Kashyap <[email protected]> wrote: >> On Thu, Mar 17, 2011 at 12:30 AM, C K Kashyap <[email protected]> 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-1.2.0.3. >> >> Does it work if you use it in a Haskell source file, instead of GHCi? > > Nope, even compiling with ghc causes the error.
So then it's not a bug. The instance is defined in Data.Time.Format.Parse, and Data.Time.Calendar doesn't import that module. This, however is a bug, I think: Prelude> import Data.Time Prelude Data.Time> read "2011-10-10" :: Day ... no instance for (Read Day) ... Prelude> :m +Data.Time Prelude Data.Time> read "2011-10-10" :: Day 2011-10-10 Erik _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
