Am Sa., 15. Aug. 2020 um 02:54 Uhr schrieb John Cowan <xxxxxx@ccil.org>:

> (guard e
>   (let ((set (foreign-status-ref e 'set)))
>     ((eqv? set 'posix) (posix-handler e))
>     ((eqv? set 'windows) (windows-handler e))
>     ((eqv? set 'postgresql) (postgresql-handler e))
>     ...))

This is not a well-formed guard expression, is it? The way "guard" has
been devised, the selection of each handler should depend on a quick
test that just has the exception as a free variable.

Here, It would be something like

(eq? (foreign-status-ref e 'set) 'posix)

but this can hopefully be shortened by some convenience predicate.

Marc