[racket] variables within macros

Greg Hendershott's pages may be of interest to you:
http://www.greghendershott.com/fear-of-macros/
And I think you can find some worthwhile notes on the PLT blog too.

Laurent


On Thu, Jan 17, 2013 at 11:08 AM, Tim Brown <tim.brown at cityc.co.uk> wrote:

> Danny, Jens Axel, Ian, Ray,
>
> Thanks for your input... I'm absorbing it all.
>
> I need some really basic help getting my head around all of this.
> Where can I download a copy of "How to Design Macros"? :-)
>
> Tim
>
>
> On 16/01/13 17:22, Jens Axel Søgaard wrote:
>
>> Hi Tim,
>>
>> Danny explains the problem well.
>> To accumulate a result, one must stay in the same
>> same dynamic extent. One way to solve the problem
>> is to use local-expand. In some cases one can
>> write expanders  for the forms, that needs analysing
>> and call them directlye (rather than write a macro
>> for the subform and then let the expander
>> call a macro transformer).
>>
>> Below is a short example, which incidently shows
>> an alternative solution the local-expand problem,
>> I had the other day
>> (see  http://www.mail-archive.com/**users@racket-lang.org/**msg15937.html<http://www.mail-archive.com/users@racket-lang.org/msg15937.html>).
>>
>> If you need local-expand, then see Matthews answer on how
>> to use definition contexts with local-expand.
>>
>> /Jens Axel
>>
>
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