Re: [racket-users] continuing after a user break
It does seem useful. It would require some thought because the exception handler cannot escape until there is no possibility of resuming which seems like it would have UI implications. This would also cause some REPL interactions to behave differently when they are in the break-resumable context (notably those involving continuations and related things). But I agree it seems worth thinking about. Since it's been 7 days and I've not made any more progress than that, I guess that the best I can offer is advice if someone else wants to give it a try. Robby On Mon, Jul 27, 2015 at 5:48 PM, John Carmack 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. > > -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. -- 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
As Jay indicated, I believe in eating some of my dog food so I do use DrRacket for writing Racket programs. But yes, as he also said I tuned DrRacket to fit my taste a bit and it works reasonably well for maintaining my friends in the htdp package. And I will admit that on rare occasions I temporarily switch to Emacs to get work done (rarely but often enough that I am forced to say so here). We are not vendors and DrRacket is open source, written in Racket. You can change DrRacket and you can submit pull requests. I am pretty sure that we will integrate most of these though there are some constraints we will impose on *SL (the teaching languages) and possibly the REPL. [REPL: I spent 20 years in Emacs for everything: programming, writing, shell, mail, newsgroups, predecessors of irc, etc. Soon after I got started I pair programmed with my advisor and I noticed that he killed his REPL and restarted it for every load. (He still uses this style; watch his Strange Loop video.) I wondered why. Then I worked on projects with him and I noticed how our abstraction-oriented style based on lambda got me into hot water when I loaded expressions/definitions and didn't kill the repl. DrRacket implements this style by default and keeps many beginners from wondering about seriously strange things.] -- Matthias On Jul 27, 2015, at 4:48 PM, John Carmack 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. > > -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. -- 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. smime.p7s Description: S/MIME cryptographic signature
Re: [racket-users] continuing after a user break
2015-07-28 1:48 GMT+03:00 John Carmack : > Any chance that could make it in as a DrRacket feature? Btw, this question is a valuable reason why I love Lisp and Emacs -- it's possible to implement almost any desired feature on one's own without waiting from vendor ;) -- // Dmitry. -- 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 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." - D&C 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.
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
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.
