[Haskell-cafe] Re: derive & Drift - some help please

[Gü?nther Schmidt]

Hi Alexander,

this does the trick!

Günther

Alexander Dunlap schrieb:
> Well you can do
> 
>> deriving instance Typeable LocalType
> 
> etc. if you enable the DeriveDataTypeable and StandaloneDeriving
> extensions. You will get other error messages for missing instances;
> just keep adding
> 
>> deriving instance Typeable Day
> 
> etc. Eventually, you will need to implement an instance by hand for
> Pico, because Pico's data constructors are not exported from
> Data.Fixed. I'm not very familiar with Data and Typeable so I can't
> help you there, but you can probably look at some existing instances
> for help.
> 
> Hope that's useful for you.
> 
> Alex
> 
> On Sun, Mar 8, 2009 at 12:40 PM, Gü?nther Schmidt <gue.schmidt at web.de> wrote:
>> Hi Alexander,
>>
>>
>> well I have this:
>>
>> newtype AdmissionDate = AdmDt LocalTime
>>        deriving (Data,Typeable ..)
>>
>> at least that's where I wonna get.
>>
>> I don't know how to create the proper instance declarations though for
>> LocalTime.
>>
>> AdmissionDate is an element of a larger data structure, this data structure
>> for instance also has a
>>
>> newtype DischargeDate = DchrgDt LocalTime
>>        deriving (Data,Typeable ...)
>>
>> With my haskell work so far I was blessedly free of the need for deriving..
>> Until now ...
>>
>> Günther
>>
>>
>> Alexander Dunlap schrieb:
>>> What problems are you encountering?
>>>
>>> Alex
>>>
>>> On Sun, Mar 8, 2009 at 11:58 AM, G?uenther Schmidt <redcom at fedoms.com>
>>> wrote:
>>>> Hi Sterling,
>>>>
>>>> sry, but I can't get it to work.
>>>>
>>>> Günther
>>>>
>>>> Sterling Clover schrieb:
>>>>> You shouldn't need any extra tools for this. A combination of the
>>>>> StandaloneDeriving and DeriveDataTypeable extensions in GHC should
>>>>> suffice.
>>>>>
>>>>> Cheers,
>>>>> S.
>>>>>
>>>>> On Sun, Mar 8, 2009 at 10:30 AM, Gü?nther Schmidt <gue.schmidt at web.de
>>>>> <mailto:gue.schmidt at web.de>> wrote:
>>>>>
>>>>>   Hi,
>>>>>
>>>>>   I need to derive Data, Typeable for Data.Time.LocalTime. I had hoped
>>>>>   to use either derive or DrIFT to generate the instance declarations
>>>>>   for it.
>>>>>
>>>>>   I tried to understand the respective user manuals but it's still all
>>>>>   Greek to me.
>>>>>
>>>>>   Someone please help!
>>>>>
>>>>>   Günther
>>>>>
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