Re: [Haskell-cafe] Please help : Data.Time.Format parseTime
As a more general response, be careful with parsing dates, because as far as I can tell, it is easy to print times (with formatTime) that cannot be parsed (with parseTime). Specifically, if you strip the padding (of zeros or spaces) there is no way to parse it back in. So parseTime . formatTime is not an identity for anything that cuts out padding. (it results in Nothing for those cases). Perhaps this is because too much data is lost (doesn't seem like this would necessarily be the case), but it does seems like an outstanding problem with parseTime. If I'm wrong, and, for example, a non-zero padded month (which occurs quite frequently in the world), which can easily be printed with "%-m", can be parsed in without pre-parsing and inserting zeros as appropriate first, I would be happy to hear how! On Jun 14, 2011, at 5:32 PM, Dmitri O.Kondratiev wrote: > Magnifique, ca marche! Grand merci, Vincent! > > On Wed, Jun 15, 2011 at 1:16 AM, Vincent Gerard wrote: > Hello Dmitri, > > It seems that your format pattern does not match exactly the format of > the input, thus the parser returns Nothing. > > Try the following format string which seems to work with your date: > > parseTime defaultTimeLocale "%m/%d/%Y %l:%M:%S %p" ds :: Maybe > UTCTime returns : Just 2009-10-11 19:04:28 UTC > > The parsings errors in your format could come from > . %D expects a 2 char year > . %H expects a 0 padded hour (like 07, not 7) > > Regards, > > Vincent Gerard > > On Wed, 15 Jun 2011 00:33:56 +0400 > "Dmitri O.Kondratiev" wrote: > > > I am trying to convert data string to time: > > > > import Data.Time > > import Data.Time.Format > > import Locale > > > > ds = "10/11/2009 7:04:28 PM" > > t = parseTime defaultTimeLocale "%D %H:%M:%S %p" ds :: Maybe UTCTime > > > > and get "Nothing". > > What is wrong? > > > > Thanks ! > > Dmitri. > > > > > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please help : Data.Time.Format parseTime
Magnifique, ca marche! Grand merci, Vincent! On Wed, Jun 15, 2011 at 1:16 AM, Vincent Gerard wrote: > Hello Dmitri, > > It seems that your format pattern does not match exactly the format of > the input, thus the parser returns Nothing. > > Try the following format string which seems to work with your date: > > parseTime defaultTimeLocale "%m/%d/%Y %l:%M:%S %p" ds :: Maybe > UTCTime returns : Just 2009-10-11 19:04:28 UTC > > The parsings errors in your format could come from > . %D expects a 2 char year > . %H expects a 0 padded hour (like 07, not 7) > > Regards, > > Vincent Gerard > > On Wed, 15 Jun 2011 00:33:56 +0400 > "Dmitri O.Kondratiev" wrote: > > > I am trying to convert data string to time: > > > > import Data.Time > > import Data.Time.Format > > import Locale > > > > ds = "10/11/2009 7:04:28 PM" > > t = parseTime defaultTimeLocale "%D %H:%M:%S %p" ds :: Maybe UTCTime > > > > and get "Nothing". > > What is wrong? > > > > Thanks ! > > Dmitri. > > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please help : Data.Time.Format parseTime
Hello Dmitri, It seems that your format pattern does not match exactly the format of the input, thus the parser returns Nothing. Try the following format string which seems to work with your date: parseTime defaultTimeLocale "%m/%d/%Y %l:%M:%S %p" ds :: Maybe UTCTime returns : Just 2009-10-11 19:04:28 UTC The parsings errors in your format could come from . %D expects a 2 char year . %H expects a 0 padded hour (like 07, not 7) Regards, Vincent Gerard On Wed, 15 Jun 2011 00:33:56 +0400 "Dmitri O.Kondratiev" wrote: > I am trying to convert data string to time: > > import Data.Time > import Data.Time.Format > import Locale > > ds = "10/11/2009 7:04:28 PM" > t = parseTime defaultTimeLocale "%D %H:%M:%S %p" ds :: Maybe UTCTime > > and get "Nothing". > What is wrong? > > Thanks ! > Dmitri. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Please help : Data.Time.Format parseTime
On Tue, 14 Jun 2011 22:33:56 +0200, Dmitri O.Kondratiev wrote: I am trying to convert data string to time: import Data.Time import Data.Time.Format import Locale ds = "10/11/2009 7:04:28 PM" t = parseTime defaultTimeLocale "%D %H:%M:%S %p" ds :: Maybe UTCTime and get "Nothing". What is wrong? According to the documentation[0], %D expects a two digit year. Regards, Henk-Jan van Tuyl [0] http://hackage.haskell.org/packages/archive/time/latest/doc/html/Data-Time-Format.html#v:formatTime -- http://Van.Tuyl.eu/ http://members.chello.nl/hjgtuyl/tourdemonad.html -- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Please help : Data.Time.Format parseTime
I am trying to convert data string to time: import Data.Time import Data.Time.Format import Locale ds = "10/11/2009 7:04:28 PM" t = parseTime defaultTimeLocale "%D %H:%M:%S %p" ds :: Maybe UTCTime and get "Nothing". What is wrong? Thanks ! Dmitri. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
