Re: [racket-users] Re: Fast way to map over a list many times, changing ONE element each time?
My 1000 numbers were so small that they weren't reliable. Change the `num-runs-per-f` and experiment yourself, if you'd like. The code is attached. -- 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. map-once.rkt Description: Binary data
[racket-users] Re: Fast way to map over a list many times, changing ONE element each time?
I timed all these with `sqr` on a list of 1 `(random)`. Luke's (my) first one: cpu time: 4706 real time: 4699 gc time: 3673 Luke's second one: cpu time: 5401 real time: 5393 gc time: 4136 Jon's first one: cpu time: 9734 real time: 9728 gc time: 8007 Jon's second one (tested on a vector of course): cpu time: 1198 real time: 1195 gc time: 883 Jens' first one: cpu time: 5622 real time: 5618 gc time: 4800 Jens' second one: cpu time: 4393 real time: 4391 gc time: 3935 I thought Jens' second one would be faster. The vector's results are promising. -- 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] Fast way to map over a list many times, changing ONE element each time?
Say I have a list ls and I want to produce a list of lists where the i'th list has the i'th element of ls tripled, but all other elements are the same. e.g. '(3 5 7) = '((9 5 7) (3 15 7) (3 5 21)) What is a fast way to do this? I could do a loop with appending. (define (map-once f ls) (let M ([sooner null] [later ls]) (if (null? later) null (cons (append sooner (list (f (car later))) (cdr later)) (M (append sooner (list (car later))) (cdr later)) - (map-once sqr '(4 5 6)) '((16 5 6) (4 25 6) (4 5 36)) Unfortunately, this is very slow messy. I have to do 2 big appends for every element is the return list. Here is a cleaner-looking, but still slow way: (define (list-set ls i new-val) (let-values ([(sooner later) (split-at ls i)]) (append sooner (list new-val) (cdr later (define (map-once f ls) (for/list ([i (in-naturals)] [elm (in-list ls)]) (list-set ls i (f elm I'm thinking a good implementation might use continuations somehow? Maybe of vector-set (without the exclamation point) existed, I could use it? -- 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: OK to post Redex and HtDP questions here?
I don't post here a whole lot, but From the description of this mailing list: This is the right place for discussion of nearly all Racket issues. So I'd say yeah. -- 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: Get list of all predefined identifiers for use in vim syntax highlighting
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 exclusively use it. The reader's distinction between keywords and builtins is good enough for me. -Eventually, it would be nice to have keywords builtins determined by the #lang line and any calls to require. However, I'm not sure if this is possible/practical in vim. -- 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] strange bug with racket/gui
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 inside the code but not in the REPL afterwards? Second, I have some *bad* code in the attached file: (define canvas (void)) (define dc (void)) (new canvas% [parent frame] [paint-callback (λ (c d) (set! canvas c) (set! dc d))]) I couldn't find a direct way to get `dc` and `canvas`, and I didn't want to put my entire code in the function that paint-callback calls. Is there a more straightforward way to get these values? Thanks! -Luke -- 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. graphics-2.rkt Description: Binary data
[racket-users] Get list of all predefined identifiers for use in vim syntax highlighting
For those who like to write their racket code in vim, the plugin https://github.com/wlangstroth/vim-racket is pretty essential. Unfortunately, it is outdated and many of the new predefined identifiers (e.g. set-add!) are not highlighted. I added a few of these in my personal settings, but it would be nice to have a text file with every special form and every function listed. Is this list floating around somewhere? If not, is there an easy way to generate it? -- 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] Get list of all predefined identifiers for use in vim syntax highlighting
Thank you very much, Jens. This appears to be all the functions. Do you know of anything for special forms? This would include for, for/and, define-values, etc... On Monday, June 1, 2015 at 11:09:31 AM UTC-4, Jens Axel Søgaard wrote: Hi Luke, This script generates a large list of keywords. It was used to generate the keywords for the Github highlighter. https://github.com/soegaard/racket-highlight-for-github/blob/master/generate-keywords.rkt /Jens Axel 2015-06-01 17:07 GMT+02:00 Luke Miles rashrep...@gmail.com: For those who like to write their racket code in vim, the plugin https://github.com/wlangstroth/vim-racket is pretty essential. Unfortunately, it is outdated and many of the new predefined identifiers (e.g. set-add!) are not highlighted. I added a few of these in my personal settings, but it would be nice to have a text file with every special form and every function listed. Is this list floating around somewhere? If not, is there an easy way to generate it? -- 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...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- -- Jens Axel Søgaard -- 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.
