[racket-users] stream-lazy
Hi Modules racket/streams and srfi/41/streams do not export stream-lazy. Module srfi/41/streams exports stream-lambda and define-stream. Module racket/streams does not export these. When Phil Bewig was preparing his srfi 41, I had may discussions with him about providing stream-lazy to the user. He preferred not to do so and in stead provided stream-lambda and define-stream. I advocate stream-lambda or stream-lazy to be exported from racket/streams. Personally I prefer stream-lazy. The attached example shows why stream-lazy can be useful. stream-lambda may do as well, because, as the example shows, stream-lazy can be exposed by means of stream-lambda. Best wishes, Jos Koot -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. equal-fringe.rkt Description: Binary data
[racket-users] TR: Option values
Hi all, Writing TR code, I find that the more I use the Option type, the more I want something like Haskell’s Maybe monad. Is there any existing tool I’m missing, that provides for applying functions to values of type (Option x), by propagating failures? If not, would it be sensible to include such a thing in one of the TR packages as a standard TR library? Unfortunately, I haven’t figured out a way to write a variable-arity version: This fails, presumably because TR’s occurrence typing is (quite understandably) not able to do much with ormap: (: maybe-apply (All (a b) ((a * - (Option b)) (Option a) * - (Option b (define (maybe-apply f . vs) (if (ormap not vs) #f (apply f vs))) Error: Type Checker: Bad arguments to function in `apply': Domain: a * Arguments: (Listof (U False a)) * in: (apply f vs) But even having a trio of unary/binary/ternary versions would be very helpful. I’ve put up a tiny and crude library here https://github.com/RenaissanceBug/option-bind, but imagine there’s a better way to bring it into the racket ecosystem. Thoughts? Cheers, jmj -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] saving a BMP in racket
On Jul 23, 2015, at 2:47 AM, copycat kangren.c...@gmail.com wrote: Yes, i can and will try with the old imagemagick bindings. On Thursday, July 23, 2015 at 6:28:00 AM UTC+8, johnbclements wrote: On Jul 20, 2015, at 4:11 AM, copycat kangren.c...@gmail.com wrote: Hi, not sure if this is considered a bug? (send model save-file model1.bmp 'bmp) save-file in bitmap%: kind saving not yet implemented: 'bmp I found this link, and it's been 2 years since. Is it an update that will take a long time? http://stackoverflow.com/questions/14987784/how-can-i-save-a-bmp-in-racket My guess is that no one is currently working on this. I just took a quick 1-minute look at the respective wikipedia pages for PNGs and BMPs, and it appears that although in principle BMP can support things that PNG cannot (e.g., arbitrary bit-depth color channels), a PNG is not likely to lose any of the information associated with a racket bitmap%, meaning that generating a PNG and then converting it to a BMP using an external utility should produce the same result as directly creating a BMP. Granted, it’s not as convenient. Given this, would you consider this issue resolved if the word “yet” was simply removed from the error message? I’ve reworded this error message and pushed the change; I will cheerfully revert it if anyone objects. John Best, John Clements -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Fwd: Re: [racket-users] What limits would you put on racket?
I also forgot to reply to the list. -- Forwarded message -- From: Doug Williams m.douglas.willi...@gmail.com Date: Jul 23, 2015 9:21 AM Subject: Re: [racket-users] What limits would you put on racket? To: Sayth Renshaw flebber.c...@gmail.com Cc: If you're strictly comparing Racket to other Lisp dialects, I would say there is never any reason to go to a different Lisp dialect. The main exception would be if there is some specific, existing capability in a different language that you require. But, that is not a dialect issue. I regularly use Racket for complex analysis tasks. The mathematic and plotting capabilities available are superior (in my opinion) to other dialects. Your mileage may vary. Doug Williams On Jul 22, 2015 11:51 PM, Sayth Renshaw flebber.c...@gmail.com wrote: Hi Just getting reacquainted with Racket going back through HTDP 2nd edition and the edx intro course. Is there a point where you would say yeah Racket shouldn't go there, it's best at A B or C you should go to Chez, Sbcl, CCL etc. Sayth -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Scribble undefined tags
On Jul 25, 2015, at 2:48 PM, Matthew Flatt mfl...@cs.utah.edu wrote:
Do the broken references show up when rendering docs with `raco setup`
or `raco pkg {install,update}`, or do they show up when running
`scribble` directly on the .scrbl file?
The former.
If you're seeing this behavior when using `raco setup` or `raco pkg`,
then it sounds like a bug. Using collection-based paths instead of
relative paths may be a good idea (to enable directly running
`scribble`, for example), but it shouldn't be required.
Good to know.
I’ve cleared out all the undefined tag warnings, but without a complete
understanding of what’s going on. Some further info:
The code I’m documenting is all in TR.
Some of the undefined-tag warnings I saw resulted from the same identifier
being imported (with for-label) from multiple modules.
When I discovered the multiple-imports problem, I managed to eliminate most of
the warnings, but until minutes ago I was stuck with a few yet:
raco setup: 0 running: pkgs/jwt/net/jwt/jwt.scrbl
raco setup: WARNING: undefined tag in pkgs/jwt/net/jwt/jwt.scrbl:
raco setup: ((lib net/jwt.rkt) decode-jwt)
raco setup: ((lib net/jwt.rkt) decode/verify)
raco setup: ((lib net/jwt.rkt) verify-jwt)
raco setup: ((lib typed/json.rkt) JSExpr)
I’m ignoring the JSExpr one, since I know JSExpr is not in the Scribble docs
yet. (FWIW, about a month ago I put in a pull request that would add that to
the TR docs https://github.com/racket/typed-racket/pull/155.)
Here’s the Scribble file:
https://github.com/RenaissanceBug/racket-jwt/blob/master/net/jwt/jwt.scrbl
Here’s the net/jwt.rkt file referenced above:
https://github.com/RenaissanceBug/racket-jwt/blob/master/net/jwt.rkt
It pulls in, and then re-provides, the three offending names from this file:
https://github.com/RenaissanceBug/racket-jwt/blob/master/net/jwt/encode-decode.rkt
I’ve checked that those names are not being required from any other module by
the Scribble file.
And then I happened to add this line
https://github.com/RenaissanceBug/racket-jwt/blob/master/net/jwt/jwt.scrbl#L131,
and the undefined-tag errors magically went away.
Since there’s no obvious likely connection between that section header and the
names being (un)defined, my best guess at what happened is that
I discovered the relationship to names imported from two sources, and started
adjusting my imports
I made some unrelated changes to the Scribble doc
I rebuilt the docs and got only the four errors I pasted above
I removed the remaining double-imports
I rebuilt the docs and saw no change — maybe raco setup wasn’t recompiling the
.scrbl file because it hadn’t been edited?
I made an unrelated change to jwt.scrbl, causing raco setup to detect jwt.scrbl
had changed and do something differently
The remaining errors then disappeared
(And when I tried removing the section header again, the errors didn’t return.)
Still, I’ve no idea what exact connection there might be to multiple imports of
the same name, but AFAICT that was related. I hope this info, vague as it is,
is still of some help.
Best,
jmj
At Fri, 24 Jul 2015 21:56:45 -0700, Matthew Butterick wrote:
I’ve always found that it’s more reliable to use fully-qualified package
names with `for-label`, e.g.
(require (for-label jordan/package))
rather than
(require (for-label main.rkt))
Once upon a time I had similar problems, and noticed that fully-qualified
names is the habit used in many internal Racket packages. The reasons why
this works are dimly remembered. I presume it has something to do with the
fact that all Scribble docs are rendered into the main docs directory for
your installation, thus breaking local paths that wander outside your
'scribblings' subdirectory.
On Fri, Jul 24, 2015 at 8:58 AM, Jordan Johnson j...@fellowhuman.com wrote:
Hi all,
I have a file *main.scrbl* in the same directory as a file *main.rkt*. In
the .scrbl file, I have
(require (for-label main.rkt))
and several *defproc* and *defstruct** forms. For some reason, one of my
*defstruct** forms works as expected, while all of the other *defstruct**
and
*defproc* forms produce undefined-tag warnings (when I build the docs via
raco setup), and compile to a red-underlined name in the resulting HTML.
In DrRacket, mousing over the struct names in *main.scrbl*, I see a pink
arrow with a question mark pointing from the *for-label* line to the
struct name, and DrRacket correctly reports that the struct name’s binding
is imported from *main.rkt*.
What might I be missing, that could be causing undefined-tag errors?
Thanks,
jmj
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[racket-users] Slack team for racket
Hi Everyone! For anyone out there who finds IRC too daunting and difficult to use, there's a slack team created just for racketlang at http://racket.slack.com. Get invites to the team at http://racket-slack.herokuapp.com. Cheers, Jason -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] must manually delete compiled file for tests/racket/package.rkt ?
I updated my tree today and ran make, and ran into this error: raco pkg update: packages conflict package: compatibility-test package: racket-test module path: tests/racket/package I did a little investigating, and sure enough, I can see that while this file used to be a part of the racket-test package, it’s now a part of compatibility-test. I went into the compiled subdirectory, and manually deleted package*.zo, and it looks like things are going fine now, but it seems to me that this shouldn’t have happened… should it? John -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] must manually delete compiled file for tests/racket/package.rkt ?
Yes, this is a limitation of `raco pkg` that is on my list to repair. It happens when a file is removed from a linked package, such as the packages in pkgs, and only when the corresponding .zo file is not yet deleted. It's not an actual conflict, because `raco setup` will soon remove the .zo file, but `raco pkg` doesn't yet take future action that into account. At Sun, 26 Jul 2015 18:13:51 -0400, 'John Clements' via users-redirect wrote: I updated my tree today and ran make, and ran into this error: raco pkg update: packages conflict package: compatibility-test package: racket-test module path: tests/racket/package I did a little investigating, and sure enough, I can see that while this file used to be a part of the racket-test package, it’s now a part of compatibility-test. I went into the compiled subdirectory, and manually deleted package*.zo, and it looks like things are going fine now, but it seems to me that this shouldn’t have happened… should it? John -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] UDP bytes?
Sorry, list, for dumb unprofessional question, but I'm not even amateur programmer) How can I convert string and floats to bytes, that can be passed to udp-send? Tried real-floating-point-bytes and string-bytes/utf-8 but it produces not compatible output. Any best practices of forming udp datagrams in racket exists? -- You received this message because you are subscribed to the Google Groups Racket Users group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
