On Sun, 14 Aug 2005, [ISO-8859-1] Jens Axel Søgaard wrote:

> The purpose of the do-primes example was to show that simple destructuring is
> possible without using syntax-case.

Understood.

>>> in the case were it is neccessary to use normal Scheme operators, most
>>> often a call to syntax->list, which turns a syntax-object representing a
>>> list into a list of syntax-objects, is enough to solve the problem.
>>
>> This can entail a rather expensive performance hit.
>
> What is "rather expensive"?

I was referring to having to walk the expression with syntax->list to the
required depth before being able to use, e.g., SRFI-1 operations on it.  It may
not always be expensive, but it could be.

Cheers
Andre