Re: [racket-users] derp-3 not working, could be bug in either derp-3 or racket (I'm guessing it's Racket)

['John Clements' via Racket Users]

> On Aug 29, 2016, at 5:09 PM, Matthew Flatt  wrote:
> 
> Thanks for the report! I think I have a repair, and I'll push as soon
> as it passes a build and tests.

Thanks!

John



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Re: [racket-users] derp-3 not working, could be bug in either derp-3 or racket (I'm guessing it's Racket)

[Matthew Flatt]

Thanks for the report! I think I have a repair, and I'll push as soon
as it passes a build and tests.

At Mon, 29 Aug 2016 19:45:40 -0400, "'John Clements' via Racket Users" wrote:
> In Racket v6.6.0.4, it appears that the derp-3 parser-based-on-derivatives 
> (as 
> it now exists in the https://bitbucket.org/ucombinator/derp-3 bitbucket repo) 
> doesn’t run at the command-line.
> 
> Specifically, if I download this repo and run
> 
> racket pyparse.rkt
> 
> … in the src/ directory, I get this output:
> 
> pcp143094pcs:/tmp/a/b/derp-3/src (git)-[master]- clements> racket 
> ./pyparse.rkt 
> link: bad variable linkage;
>  reference to a variable that has the wrong procedure or structure-type shape
>   reference phase level: 0
>   variable module: "/tmp/a/b/derp-3/src/derp.rkt"
>   variable phase: 0
>   reference in module: "/tmp/a/b/derp-3/src/pyparse.rkt"
>   in: set-node-tag1!
>   context...:
>/tmp/a/b/derp-3/src/pyparse.rkt: [running body]
>/tmp/a/b/derp-3/src/pyparse.rkt: [running body]
> 
> It is worth noting that this does not happen when running in DrRacket. 
> instead, you get (correctly) an error about missing command-line arguments. 
> Furthermore, stripping out later parts of the pyparse.rkt file results in a 
> file that still signals the above error at the command-line, but runs without 
> error in DrRacket.
> 
> After digging through the source a bit, I notice several things:
> 
> 1) there is no occurrence of ‘tag1’ in the source.
> 2) There is a structure named ‘node’ that has a field named ‘tag’
> 3) Derp-3 is doing some interesting things with structures: specifically, it 
> has an “unsafe-struct” form, and node is one of them.
> 
> Since this code worked in earlier versions of Racket, it seems likely that 
> either 
> 
> 1) This is a newly introduced bug in Racket, or
> 2) This is a newly *fixed* bug in Racket, or
> 3) This is a consequence of changes to the syntax system associated with the 
> transition to scope sets.
> 
> Because of the fact that I don’t see the error in DrRacket, I’m inclined to 
> lean toward number 1, and more specifically toward optimizations that may be 
> present in the command-line that aren’t present in DrRacket, or more 
> generally 
> simply differences in the .zo files generated by the two systems (if I 
> understand our current compilation process correctly).
> 
> I’m guessing that the next step in fixing this would be to attempt to convert 
> ‘node’ to a standard structure to see if the problem goes away, but I thought 
> I’d ask you folks first.
> 
> Best,
> 
> John
> 
> 
> 
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[racket-users] derp-3 not working, could be bug in either derp-3 or racket (I'm guessing it's Racket)

['John Clements' via Racket Users]

In Racket v6.6.0.4, it appears that the derp-3 parser-based-on-derivatives (as 
it now exists in the https://bitbucket.org/ucombinator/derp-3 bitbucket repo) 
doesn’t run at the command-line.

Specifically, if I download this repo and run

racket pyparse.rkt

… in the src/ directory, I get this output:

pcp143094pcs:/tmp/a/b/derp-3/src (git)-[master]- clements> racket ./pyparse.rkt 
link: bad variable linkage;
 reference to a variable that has the wrong procedure or structure-type shape
  reference phase level: 0
  variable module: "/tmp/a/b/derp-3/src/derp.rkt"
  variable phase: 0
  reference in module: "/tmp/a/b/derp-3/src/pyparse.rkt"
  in: set-node-tag1!
  context...:
   /tmp/a/b/derp-3/src/pyparse.rkt: [running body]
   /tmp/a/b/derp-3/src/pyparse.rkt: [running body]

It is worth noting that this does not happen when running in DrRacket. instead, 
you get (correctly) an error about missing command-line arguments. Furthermore, 
stripping out later parts of the pyparse.rkt file results in a file that still 
signals the above error at the command-line, but runs without error in DrRacket.

After digging through the source a bit, I notice several things:

1) there is no occurrence of ‘tag1’ in the source.
2) There is a structure named ‘node’ that has a field named ‘tag’
3) Derp-3 is doing some interesting things with structures: specifically, it 
has an “unsafe-struct” form, and node is one of them.

Since this code worked in earlier versions of Racket, it seems likely that 
either 

1) This is a newly introduced bug in Racket, or
2) This is a newly *fixed* bug in Racket, or
3) This is a consequence of changes to the syntax system associated with the 
transition to scope sets.

Because of the fact that I don’t see the error in DrRacket, I’m inclined to 
lean toward number 1, and more specifically toward optimizations that may be 
present in the command-line that aren’t present in DrRacket, or more generally 
simply differences in the .zo files generated by the two systems (if I 
understand our current compilation process correctly).

I’m guessing that the next step in fixing this would be to attempt to convert 
‘node’ to a standard structure to see if the problem goes away, but I thought 
I’d ask you folks first.

Best,

John



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[racket-users] Spreadsheet widget?

[David Storrs]

Is there a spreadsheet in Racket?  I dug through the list and found a
mailing list thread
 from
2008 but nothing since then.  I also checked the  Widget Gallery
 and didn't see one.

Greg Cooper, in that thread you said
 that
you'd be interested in talking/working with someone to make this happen.
Is that still the case, and do you have time / interest?  Even if you don't
want to take it on yourself I'd sure appreciate having someone to talk it
through with so I can judge if it's something I can do.

(If anyone else has time/interest in talking it out, that would also be
great.)

Dave

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Re: [racket-users] Typed racket and continuations

[Matthias Felleisen]

Continuations don’t return. In a set-oriented type system this means their 
result type is the empty set: 

#lang typed/racket

(define-type EmptySet (U))

(: d-or-s (U False (-> Number EmptySet)))
(define d-or-s #f)

(: double-or-same (-> Number Number))
(define (double-or-same x)
 (call/cc (lambda ({c : (-> Number EmptySet)})
(set! d-or-s c)
(+ x x


> On Aug 29, 2016, at 2:18 PM, Sourav Datta  wrote:
> 
> Hey everyone,
> 
> I am a beginner in Racket and recently learned the basic concepts of 
> continuations. I like Racket's support of multiple types of continuations as 
> opposed one type in Scheme. Recently I also started learning about typed 
> Racket. My problem is, I am not sure how I can annotate a continuation in a 
> typed racket program. For example, when trying to annotate the below code:
> 
> #lang racket
> 
> (define d-or-s #f)
> 
> (define (double-or-same x)
>  (call/cc (lambda (c)
> (set! d-or-s c)
> (+ x x
> 
> in typed racket, I can see that double-or-same function can have type 
> (Integer -> Integer). But what should be the type of the variable do-or-s? If 
> it is Any, then it cannot be called like a function after the continuation is 
> set to it. So basically my question is how can we type annotate different 
> types of continuations starting from a simple one like the above? Also a 
> pointer to the relevant section in typed racket docs would be great.
> 
> Thanks!
> 
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[racket-users] Typed racket and continuations

[Sourav Datta]

Hey everyone,

I am a beginner in Racket and recently learned the basic concepts of 
continuations. I like Racket's support of multiple types of continuations as 
opposed one type in Scheme. Recently I also started learning about typed 
Racket. My problem is, I am not sure how I can annotate a continuation in a 
typed racket program. For example, when trying to annotate the below code:

#lang racket

(define d-or-s #f)

(define (double-or-same x)
  (call/cc (lambda (c)
 (set! d-or-s c)
 (+ x x

in typed racket, I can see that double-or-same function can have type (Integer 
-> Integer). But what should be the type of the variable do-or-s? If it is Any, 
then it cannot be called like a function after the continuation is set to it. 
So basically my question is how can we type annotate different types of 
continuations starting from a simple one like the above? Also a pointer to the 
relevant section in typed racket docs would be great.

Thanks!

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Re: [racket-users] Error message from GUI

[Dmitry Pavlov]

Hello,

Sorry for dropping out of the conversation for a while.

Here is the smallest example that I could produce:

#lang racket

(require racket/gui
 racket/draw
 table-panel)

(define test%
  (class
  table-panel% (super-new (dimensions '(1 1)))
  ;vertical-panel% (super-new)
  ;horizontal-panel% (super-new)

(define vpanel
  (new vertical-panel%
   (parent this)
   (border 0)
   (style '(vscroll))
   ;(min-height 1)
   ))

(for ((i (in-range 10)))
  (new button%
   (parent vpanel)
   (label (format "Button ~a" i))
   ))
))


(define frame
  (instantiate frame% ("Test")))

(void (new test% (parent frame)))

(send frame resize 200 200)
(send frame show #t)


On Windows, it results into:
..\..\Program 
Files\Racket\share\pkgs\draw-lib\racket\draw\private\syntax.rkt:252:13: 
initialization for bitmap%: bad argument combination: 192 0 #f #t 1.0


On Linux, it works, although the vertical panel ends up with a small 
visible size.


If I specify a min-height at least one to the vertical  panel, the error 
is gone, and the panel is the size of the window.
If I use vertical-panel% or horizontal-panel% instead of table-panel%, 
the error is gone, and the panel is the size of the window.


So the problem here is that table-panel% handles its children in a 
certain way, and that the height of the scrollable panel ends up zero.


I did not write table-panel. I currently do not know whether a fix 
should be done in table-panel or gui-lib.


In my program, (min-height 1) helps, so I can live with the way it is now.

Best regards,

Dmitry




On 07/30/2016 12:44 AM, Vincent St-Amour wrote:

Should this change be added to gui-lib?

Vincent


On Fri, 29 Jul 2016 10:08:46 -0500,
Dmitry Pavlov wrote:

Matthew,

Yes that works, thank!

Also I figured why the message did not show up on my "first" WinXP
installation: the spreadsheet-editor package has not been updated there.
Newer version of spreadsheet-editor sets (style '(hide-vscroll)) and
(style '(hide-hscroll)) to panels with row and column buttons.

Styles cause the error. Changing styles to just '(hscroll) and
'(vscroll) does not remove the error.
Anyway, I need those (hide-vscroll) and (hide-hscroll), so I am going to
use the patch you proposed, unless there is a more elegant solution I am
unaware of.

(Another question is why there is a stack trace in 32-bit Windows and
just a message in 64-bit Windows, but that is of purely theoretical
importance to me.)

Best regards,

Dmitry


On 07/29/2016 05:25 PM, Matthew Flatt wrote:

It may be that a guard against a 0-sized drawing dimension is needed.
The right place for the guard might be in the `get-cr` method of

   gui-lib/mred/private/wx/common/backing-dc.rkt

after `get-backing-size` is called. A zero dimension could be just
increased to 1 before passing it to `get-backing-bitmap`. Can you try
making that change to see if it solves the problem on your machine?

At Fri, 29 Jul 2016 17:08:42 +0300, Dmitry Pavlov wrote:

Jens,

Oddly, another installation of Racket 6.6 on 32-bit Windows XP not only
reproduced the error, but also gave a stack trace:

initialization for bitmap%: bad argument combination: 495 0 #f #t 1.25
 context...:
  C:\Program
Files\Racket\share\pkgs\draw-lib\racket\draw\private\syntax.rkt:252:13: next
  C:\Program
Files\Racket\share\pkgs\draw-lib\racket\draw\private\bitmap.rkt:156:2
  C:\Program
Files\Racket\collects\racket\private\class-internal.rkt:3553:0:
continue-make-object
  C:\Program
Files\Racket\collects\racket\private\class-internal.rkt:3507:0:
do-make-object
  C:\Program
Files\Racket\share\pkgs\gui-lib\mred\private\wx\common\backing-dc.rkt:122:4:
get-cr method in backing-dc%
  C:\Program
Files\Racket\share\pkgs\gui-lib\mred\private\wx\common\canvas-mixin.rkt:144:4:
do-on-paint method in ...mon/canvas-mixin.rkt:118:2
  C:\Program
Files\Racket\share\pkgs\gui-lib\mred\private\wx\common\queue.rkt:454:6
  C:\Program
Files\Racket\share\pkgs\gui-lib\mred\private\wx\common\queue.rkt:505:32
  C:\Program
Files\Racket\share\pkgs\gui-lib\mred\private\wx\common\queue.rkt:653:3

bitmap.rkt confirms your hypothesis that the first number is the width,
and the second number is the height, and they both must be positive.

  [([exact-positive-integer? w]
[exact-positive-integer? h]
[any? [b? #f]]
[any? [alpha? #f]]
[positive-real? [scale 1.0]])

The width is not specified exactly in the app. I do not know why the
height is zero. I do not use bitmaps directly, just controls and canvas.
I will go with trial and error to get a small reproducible example.

Regards,

Dmitry


On 07/28/2016 11:50 PM, Jens Axel Søgaard wrote:

Just a hunch: If 486 is a width - then the 0 could be a problematic
height?

Do you recognize the number 486?

/Jens Axel


2016-07-28 22:29 GMT+02:00