I'm currently implementing a new parallel objects policy (SAKE: Skip Animation
and Skedule) and I'm supposing that setting boolean values (even with an
accessor via send) is atomic with respect to its reads. I can't remember where
but the documentation (Guide or Reference) somewhere stated that
Hi all,
Trying to learn a bit about recursion in racket.
The question is to remove duplicates from a list while maintaining the order of
the list.
one function to remove duplicates from the left,
i.e. 1 2 1 3 2 4 5 -> 1 2 3 4 5
and one from the right.
i.e. 1 2 1 3 2 4 5 -> 1 3 2 4 5
I've go
If you uncomment the redirects to stdout and comment out the file
output, then nothing is written to the file, so that changes the
content of `(file->lines soap-file)` the second time around.
I think you wanted `(and (>=` in place of `(or (<`.
At Tue, 02 Jun 2015 15:25:07 -0400, Mark Lee wrote:
>
The documentation's discussion of drawing in a canvas may be helpful:
http://docs.racket-lang.org/gui/canvas___.html
There was also a similar thread on this list in January, and the exampe
code I posted then may be helpful:
http://lists.racket-lang.org/users/archive/2015-January/065764.html
I don't understand why you'd want this. But if you do, sleep/yield is the right
way to wait for the frame to show up and to send drawing commands.
On Jun 2, 2015, at 3:56 PM, John Smith wrote:
> Matthias,
>
> The code you provided worked, but this whole discussion was started to get
> the
You can override on-paint to draw from a bitmap and then draw into the
bitmap.
The canvas DC is access directly to the OS-provided drawing context and you
add what you need as you see fit.
Robby
On Tuesday, June 2, 2015, John Smith wrote:
> Matthias,
>
> The code you provided worked, but this
Matthias,
The code you provided worked, but this whole discussion was started to get
the code *out* of the body of a function.
Is there a way I could run your solution with
(send (send canvas get-dc) draw-rectangle 30 20 10 40)
running in the top level?
-Luke
On Tue, Jun 2, 2015 at 3:43 PM, Ma
Alexander,
Pretty strange overall.
This code displays nothing:
#lang racket
(require racket/gui/base)
(define frame (new frame%
[label "Example"]
[width 300]
[height 300]))
(define canvas
(new canvas% [parent frame]))
(define dc (send ca
You want to override on-paint:
#lang racket
(require racket/gui/base)
(define frame
(new frame%
[label "Example"]
[width 300]
[height 300]))
(define canvas
;; classes are first-class
http://www.ccs.neu.edu/home/matthias/Tmp/Class/programming-with-class/
(new (class
I have never worked with a canvas% before (I have worked with a lot of other
racket gui stuff), so I have no idea what’s going on, but watch what happens
with this:
#lang racket
(require racket/gui/base)
(define frame (new frame%
[label "Example"]
[width 300]
To all,
I've been recently working on a database and I've encountered strange behavior
when I use "call-with-atomic-output-file" and "with-output-to-file". Attached
is a sample piece of code. The correct contents of the SOAP file should be :
*First-Name : John
*Last-Name : Doe
*Gender : male
*Pho
Alexis,
Thank you for the speedy answer.
I think I correctly implemented what you described. See attached.
In the new code, no error is thrown but the rectangle is not drawn.
Reorderings of displaying the window and drawing the rectangle appear to
have no effect.
The only way I can get anything to
The problem here is that paint-callback is not called synchronously when you
create a new canvas%, so before the callback code runs, the code following the
creation of the canvas already attempts to use the drawing context.
Since canvas% implements canvas<%>, could you use the get-dc method of
2 questions.
First, when the the attached code is run, `send` throws an error because `dc`
still has the value of void.
Strangely, if I execute the below line in the REPL after the code has run,
the rectangle is successfully displayed.
(send dc draw-rectangle 30 20 10 40)
Why is `dc` still void
To provide some closure:
-The generator provided by Jens completely worked.
I set up vim to have one color & indentation for keywords,
and another color & indentation for builtins.
-The ambiguity brought up by Greg has shown not to be a problem.
I only touched racket/base, as I nearly exclusiv
Yes, it is supposed to do that correctly if you have the option turned on.
Robby
On Mon, Jun 1, 2015 at 3:50 PM, 'John Clements' via users-redirect
wrote:
>
>> On Jun 1, 2015, at 1:46 PM, Robby Findler
>> wrote:
>>
>> I think that if you don't have up to date .zo files, arbitrary badness
>> c
Yes, you can. I do it all the time.
BTW, lp2 is just the lp except that you do not need to wrap it in another
scribble file before requiring.
On Tue, Jun 2, 2015 at 8:43 PM, Tim Brown wrote:
> In the distant past, I tried to use `scribble/lp' with a program with a
> `test' sub-module (using tha
On Jun 2, 2015, at 1:20 AM, Matthew Butterick wrote:
> I've increasingly been using TR this way (= keeping code in a state where it
> can be easily toggled between typechecked and not). It works, though I'm
> still thinking about how to achieve better ergonomics with these issues,
> which don
In the distant past, I tried to use `scribble/lp' with a program with a
`test' sub-module (using that common pattern). There was some issue
with exporting the module that meant that I could not do it.
Now, in 2015, I notice that:
a. time has passed, things have developed
b. there is a `scribble
19 matches
Mail list logo
