[Template-haskell] example of derive using Template Haskell?

[S. Alexander Jacobson]

Uhm.  Ok, so I guess the question is then...
What is acceptable in 6.2 or is 6.4 coming out 
soon?

-Alex-

On Fri, 14 Jan 2005, Sean Seefried wrote:

>
> On 14/01/2005, at 7:22 AM, S. Alexander Jacobson wrote:
>
>> This is really great.  Do you have an example of use of each of these 
>> functions?
>> 
>> e.g. do I do:
>> 
>>   $(derive [Int,String,MyTime])
>> or
>> 
>>   $(derive ["Int","String","MyTime"])
>
> Oh dear, I've just realised a problem. This code only works with GHC 6.3. 
> Template Haskell has changed a lot since GHC 6.2.
>
> What you should type is
>
> $(derive [ ''Int, ''String, ''MyTime ])
>
> The '' syntax means "get the name of this type". There is also a single quote 
> syntax ' which means "get the name of this variable". This is new syntax 
> introduced with Template Haskell.
>
> Sean
>
>

______________________________________________________________
S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com