Re: using Kawa

[Jim White <jim at pagesmiths dot com>]

Dante Castiglione wrote:
> ... 
> #|kawa:5|# (StoredContinuation)
> kawa.lang.GenericError: implementation restriction: continuation can only be used once

Kawa only supports "upward" continuations.

http://www.gnu.org/software/kawa/Restrictions.html

> #|kawa:15|# (Match '("unlucky number" ?) '("unlucky number" 13))
> #f
> #|kawa:16|# (Match '("unlucky number" ?) '("unlucky number" ?))
> ()
>
> The Kreutzer-McKenzie books says that the first test should return
> false, ok, but it also says that the second should give back true,
> and in this test it returned an empty list.
>
> What may be happening?

Because it is possible to distinguish "#f" from "()", the code 
apparently relies on that.  You could convert that result to #t/#f with:

   (not (not (Match ...))

http://www.schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%25_sec_6.3.1

Jim