Re: [racket-users] saving a BMP in racket
I've updated `racket/draw` to restore support for writing BMP files. At Sun, 26 Jul 2015 11:55:51 -0400, 'John Clements' via Racket Users wrote: 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. -- 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] UDP bytes?
At Sun, 26 Jul 2015 22:42:48 -0700 (PDT), Слава ПолноеИмя wrote: 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. The `real-floating-point-bytes` bytes conversion gives you a machine representation of number. To convert bytes back to a number, you'd use `floating-point-bytes-real`. Alternatively, you could use `number-string` to get a human-readable encoding of a number, and then using `string-bytes/utf-8` to encode the string into bytes. The reverse would be `bytes-string/utf-8` and then `string-number`. Any best practices of forming udp datagrams in racket exists? A more general strategy would be to use `write` to convert anything to bytes, then then use `read` to convert back from a byte string to the value. The `read` and `write` functions work on ports, and some ports can write to or read from a byte string. This approach works for numbers, strings, symbols, lists, and other things that can round-trip with `read` and `write`. (define (value-bytes v) (define o (open-output-bytes)) (write v o) (get-output-bytes o)) (define (bytes-value bstr) (define i (open-input-bytes bstr)) (read i)) -- 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] continuing after a user break
At Mon, 27 Jul 2015 19:32:32 +, John Carmack wrote: Is it possible to continue execution after a ^b user break in DrRacket (not debugging)? It would often be useful to be able to ^b, print some global state, set some flags, and continue running. The `exn:break` exception record includes a `continuation` field. An exception handler can apply that continuation to resume from the point of the break. A significant limitation is that the handler has to be installed with `call-with-continuation-handler` or `uncaught-exception-handler`. If any `with-handlers` is in effect, it will catch any continuation and escape to the `with-handlers` form, at which point the continuation in `exn:break` cannot be applied (because it's an escape-only continuation). #lang racket (let ([orig (uncaught-exception-handler)]) (uncaught-exception-handler (lambda (exn) (if (exn:break? exn) (begin (printf continuing...\n) ((exn:break-continuation exn))) (orig exn) (let loop () (loop)) -- 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] continuing after a user break
Any chance that could make it in as a DrRacket feature? Seems likely to have moderately broad utility. Out of curiosity, what programming environment do the core Racket devs use when programming Racket? I quite like DrRacket for my projects that are only a few files, but it doesn't seem to be aimed at large scale work. -Original Message- From: Matthew Flatt [mailto:mfl...@cs.utah.edu] Sent: Monday, July 27, 2015 2:43 PM To: John Carmack Cc: Racket Users Subject: Re: [racket-users] continuing after a user break At Mon, 27 Jul 2015 19:32:32 +, John Carmack wrote: Is it possible to continue execution after a ^b user break in DrRacket (not debugging)? It would often be useful to be able to ^b, print some global state, set some flags, and continue running. The `exn:break` exception record includes a `continuation` field. An exception handler can apply that continuation to resume from the point of the break. A significant limitation is that the handler has to be installed with `call-with-continuation-handler` or `uncaught-exception-handler`. If any `with-handlers` is in effect, it will catch any continuation and escape to the `with-handlers` form, at which point the continuation in `exn:break` cannot be applied (because it's an escape-only continuation). #lang racket (let ([orig (uncaught-exception-handler)]) (uncaught-exception-handler (lambda (exn) (if (exn:break? exn) (begin (printf continuing...\n) ((exn:break-continuation exn))) (orig exn) (let loop () (loop)) -- 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] continuing after a user break
On Mon, Jul 27, 2015 at 4:48 PM, John Carmack jo...@oculus.com wrote: Any chance that could make it in as a DrRacket feature? Seems likely to have moderately broad utility. Out of curiosity, what programming environment do the core Racket devs use when programming Racket? I quite like DrRacket for my projects that are only a few files, but it doesn't seem to be aimed at large scale work. Many Racketeers use DrRacket for very big things, but I'd say that it requires a few changes to the default configuration to work really well. Such as turning on tabs and getting used to its keybindings and the ability to open module paths directly. Similarly, getting used to using the syntax arrows is really useful for big programs. I am a black sheep, however, and am often chided by Matthias because I use Emacs for everything. I use a very small piece of Greg Hendershot's racket-mode, which is partly designed to be like a good Lisp mode but for Racket and partly designed for porting over the awesome features of DrRacket. I mostly use Emacs because of the historical baggage of all my keybindings and environment and quickly getting around my files. Jay -Original Message- From: Matthew Flatt [mailto:mfl...@cs.utah.edu] Sent: Monday, July 27, 2015 2:43 PM To: John Carmack Cc: Racket Users Subject: Re: [racket-users] continuing after a user break At Mon, 27 Jul 2015 19:32:32 +, John Carmack wrote: Is it possible to continue execution after a ^b user break in DrRacket (not debugging)? It would often be useful to be able to ^b, print some global state, set some flags, and continue running. The `exn:break` exception record includes a `continuation` field. An exception handler can apply that continuation to resume from the point of the break. A significant limitation is that the handler has to be installed with `call-with-continuation-handler` or `uncaught-exception-handler`. If any `with-handlers` is in effect, it will catch any continuation and escape to the `with-handlers` form, at which point the continuation in `exn:break` cannot be applied (because it's an escape-only continuation). #lang racket (let ([orig (uncaught-exception-handler)]) (uncaught-exception-handler (lambda (exn) (if (exn:break? exn) (begin (printf continuing...\n) ((exn:break-continuation exn))) (orig exn) (let loop () (loop)) -- 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. -- Jay McCarthy http://jeapostrophe.github.io Wherefore, be not weary in well-doing, for ye are laying the foundation of a great work. And out of small things proceedeth that which is great. - DC 64:33 -- 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] Re: Slack team for racket
Le 27/07/2015 04:13, Jason Yeo a écrit : 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 Hello, IRC and a Newsgroup/Mailing-list is largely enough. I think it is better to centralize a community around 1-2 services, otherwise you have to post your question on a lot of services to hope having an answer, or to discuss about a specific subject. And honestly, if a developer finds that IRC is too complicated, he should do something else ;). But for people who already use slack.com why not ! -- 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] What limits would you put on racket?
On Fri, Jul 24, 2015 at 4:31 PM, Hendrik Boom hend...@topoi.pooq.com wrote: You might be interested in the language Styx, the language that goes with the Inferno operating system. I believe it uses reference counting up front, with full garbage collection as a backstop. The language is called Limbo. Styx is Inferno (and Plan 9) network protocol. Inferno can be run on the bare metal, but also as a user process on Linux (and some other OS's, I believe). At least on Windows too. Nowadays is completely dead, though. And, IMHO the interesting ideas in Plan 9/Inferno were NOT in the programming languages created for them. -- 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.
