Exceptions from Winders

[Eleanor Bartle]

I have a question about the interplay of exceptions and winders: if a winder throws an exception, which handler is used? Is it the one in extent at the continuation invocation site, the one at the winder installation site, or some other one?

I ask because someone I know has their own Scheme implementation (capyScheme, for those curious); they implement exceptions with continuation marks, and dynamic-wind with a global winders list, but invoke all winders in the extent of the continuation invocation. R6RS is apparently vague on the issue, referring to extents of winders but not explicitly to exception behaviour.