On Tue, Sep 10, 2019 at 1:31 AM Prokop Hapala
wrote:
> "File > Open Require Path …" ... "/usr/share/racket/pkgs/games/"
>
> it is strange ... on one computer (at work) it works, on other (at home)
> it does not want to open that directory (the dialog is a bit too
> minimalistic so I don't know w
`On Tue, Sep 10, 2019 at 1:19 AM Simon Haines <
simon.hai...@con-amalgamate.net> wrote:
> This is a rather unpleasant pitfall of the REPL. If you try to evaluate
>> the expression `(if #f some-unbound-identifier 1)`, you will see that it
>> evaluates to `#f` in the REPL but raises an unbound ident
Thanks again Philip for taking the time to reply.
This is a rather unpleasant pitfall of the REPL. If you try to evaluate the
> expression `(if #f some-unbound-identifier 1)`, you will see that it
> evaluates to `#f` in the REPL but raises an unbound identifier error in a
> module. At the REPL,
On Mon, Sep 9, 2019 at 8:17 PM Simon Haines
wrote:
> What wasted a lot of time for me is that, despite the macroexpander's
> results, the macro works as expected in the REPL. If you paste my original
> macro into DrRacket, run it, then type '(hex a)' into the REPL you get the
> expected result. I
Thanks Phillip for providing a very thorough example. There is much to
digest in there, and some novel ideas I didn't know about (attaching values
as attributes to syntax).
What wasted a lot of time for me is that, despite the macroexpander's
results, the macro works as expected in the REPL. If
On Monday, September 9, 2019 at 10:09:02 PM UTC+8, Prokop Hapala wrote:
>
> Hi,
>
> I recently found Racket when I was searching some tutorials about Lisp and
> Metaprogramming. I really like that the community around DrRacket seems to
> be very much interested in education, making talks and t
You can use a path with an even-odd-fill to cut out parts.
An example:
#lang racket
(require metapict metapict/polygons)
(define (cutout p x y r)
(defv (w h) (pict-size p))
(with-window (window 0 w 0 h)
(brushstipple (pict->bitmap p)
(eofill (rectangle (pt 0 0) (pt w h)
I'm wondering how to cut a transparent hole in something.
Say I have a rectangle and I want to make part of it transparent so
that I cn see what's behind it.
Drawing a transparent rectangle on top of it won't workm because it'll
just reveal the original rectangle.
The only way I cn see it to dr
For pedagogical examples, you may like the games that go along with the
"Realm of Racket" book, which are also in the main Racket distribution. For
example, try "Open Require Path …" for `realm/chapter2/source`, or here is
the whole collection on GitHub: https://github.com/racket/realm
On Mon, Sep
Aha,
/usr/share/racket/pkgs/games/(on Ubuntu 18.04)
Great, that is exactly what I was searching for. Thanks !
Only two things:
- how can user know that this directory was installed with racket?
DrRacket could have some link to this directory somewhere (e.g. under File
> Open, or Pack
You can find various Scheme code around the Internet, and various
textbooks that use Scheme (sometimes with the code available for download).
The Racket code for much of core Racket itself is also available, and
some of it will probably be installed already, though it's mostly not
written as b
FWIW there a lot of (small) examples at
https://rosettacode.org/wiki/Category:Racket
/Jens Axel
Den man. 9. sep. 2019 kl. 16.09 skrev Prokop Hapala :
> Hi,
>
> I recently found Racket when I was searching some tutorials about Lisp and
> Metaprogramming. I really like that the community around D
Hi,
I recently found Racket when I was searching some tutorials about Lisp and
Metaprogramming. I really like that the community around DrRacket seems to
be very much interested in education, making talks and tutorials even for
childerens. The doc pages https://docs.racket-lang.org/ seems to b
Hi Racketeers,
The community choice results are in;
1st: tessellation by Zachary Romero https://github.com/zkry/tessellation
2nd: lightsaber by Justin Zamora https://github.com/standard-fish/lightsaber
Best Entry with Butter and Local Maine Maple Syrup:
waffle-racket by Connie https://github.com/
On Mon, Sep 9, 2019 at 2:42 AM Simon Haines
wrote:
> I'm still trying to figure out why my original, terrible macro behaved the
> way it did, but I suspect I'll never know. I would have wasted a lot of
> time on that awful construct. I appreciate your help, many thanks.
>
A great way to understa
Hi Simon
I only use macros sparingly, and sympathise with your struggles to develop
macro-fu.
Some simple macros can be written quite simply using define-syntax-rule/s
and aren't that much more complex than writing functions.
To milk a bit more from this example, here's a similarly themed functi
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