GScheme cont.

[Marko Riedel]

The following message is a courtesy copy of an article
that has been posted to comp.lang.scheme as well.


Hi all,

this is to announce some new features and bug fixes re. GScheme.

Bugs:

- there was a serious bug in set! where an environment frame would be
discarded too soon; fixed

- "cut" used to work everywhere in the evaluator window; now it works
only on the current form being edited

Features:

I've implemented vectors, i.e.
- make-vector, vector?, list->vector, vector->list?
- vector-length, vector-ref, vector-set! and vector-fill!.

I've implemented "asin" and "acos".

There are two new example programs that use the new features and give
the evaluator a good workout:

- queens.scm: the classic problem, with a twist: solutions that can be
obtained from one another using one of 8 symmetries of the board are
only counted once. The output looks like this (very slow):

> (showqueens 4)
(3 1 4 2)
(2 4 1 3)

()

> (printunique 5)
. . . * . 
* . . . . 
. . * . . 
. . . . * 
. * . . . 

* . . . . 
. . . * . 
. * . . . 
. . . . * 
. . * . . 


()

- circle.scm: this program stores values of the sine and cosine
functions in a vector that are retrieved later to draw circles in
various colors (shades of green).

The URL is 
    http://www.geocities.com/markoriedelde/GNUstep/index.html.


Regards,

-- 
+------------------------------------------------------------+
| Marko Riedel, EDV Neue Arbeit gGmbH, mriedel@neuearbeit.de |
| http://www.geocities.com/markoriedelde/index.html          |
+------------------------------------------------------------+