RE: Implementing 2d-put! and 2d-get in DrScheme

["Anton van Straaten" <anton@appsolutions.com>]

I wrote:
> (define system-properties (make-hash-table-weak))
...
>             (let ((new-bucket (make-hash-table-weak)))

...which works with DrScheme v103.  For v199, replace the two occurrences of
(make-hash-table-weak) with (make-hash-table 'weak).