[plt-scheme] macro/hygiene, simple question

That's what I needed, thanks,

-- Éric


On Apr 9, 2010, at 5:37 PM, Chongkai Zhu wrote:

> Demand on what you want to achieve, this might be it:
> 
> (define-syntax (curry-Z stx)
> (syntax-case stx ()
>   ((curry-Z exp)
>    #`(lambda (#,(datum->syntax #'curry-Z 'Z)) exp))))
> 
> Chongkai
> 
> 
> Eric Tanter wrote:
>> Hi,
>> 
>> I'm trying to define a simple macro that introduces a binder over any expression (thereby capturing what would otherwise a free var in the exp):
>> 
>> example:
>> (curry-Z (lambda (x) (+ x Z)))
>> ==> (lambda (Z) (lambda (x) (+ x Z)))
>> 
>> I define the curry-Z macro as follows:
>> 
>> (define-syntax curry-Z
>>  (syntax-rules ()
>>    ((curry-Z exp)
>>     (lambda (Z) exp))))
>> 
>> However, I get a complaint that Z is undefined in the original program. This is not surprising because of hygiene. But I'd really much like to be able to force the capture to happen.
>> Is there a nice way to circumvent hygiene here and force capture?
>> 
>> Thanks,
>> 
>> -- Éric
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