IRC channel logs


back to list of logs

<mattrw>leoprikler: got it -- thanks
***apteryx_ is now known as apteryx
<topoi>When using (string-match "\." ".") I get the error "illegal character in escape sequence: #\." - doesn't "." need to be escaped with "\"?
<topoi>^-- Ohh, nevermind; "\" itself has to be escaped. ; )
<topoi>But I'm not exactly sure why (c. )
<apteryx>any idea why waiting for a pid from Shepherd's fork+exec-command (from the (shepherd service) module) takes multiple seconds? ,time (let ((pid (fork+exec-command '("sh" "-c" "echo 'hello!'")))) (waitpid pid)) --> ;; 2.436732s real time, 0.013448s run time. 0.000000s spent in GC.
<apteryx>2.43 s to fork a shell and print hello, every time
<alextee>how does guile compare to clojure?
<ahungry>clojure ecosystem, having all of maven/the jvm available, and npm/nodejs, is quite a bit bigger. Syntax wise, I like clojure, but guile/scheme has some beauty in it's simplicity
<daviid>alextee: see
<alextee>being able to use java libraries sounds pretty nice
<daviid>alextee: if that's what you want, then imo, kawa is much better then clojure - here i just wanted to point 'to the existence of lokke'
<alextee>thanks, I'm just looking for a web dev language to learn and stumbled upon clojure. I think I'll focus on the popular ones that have more support, like clojure. guile seems like it's great for C integration but I'm not sure how powerful it is for web dev (considering there's not too many popular libraries)
<flatwhatson>any thoughts about vectorization/SIMD support for guile? i guess it would need to start with teaching lightening to emit the instructions?
<leoprikler>apteryx: it looks like you're setting up a shell within a shell, how long would it take to just run "echo hello"?
<apteryx>0.12 s or something
<apteryx>I had checked
<apteryx>the hello comes out quickly but the waitpid seems to linger
<emestee>what'd be the nicest way to represent two dimensional coordinates? '(x y)? (x . y)?
<RhodiumToad>is it always going to be 2 dimensions?
<RhodiumToad>(x . y) is one cell while (x y) is two, so there's some advantage in the first; but a record might be preferable
<b4285>a list is a container for isomorphic element, so i'd go with tuples, i.e. (x . y)
<b4285>i don't know what i am talking about, shouldn't use the word "isomorphic"
<RhodiumToad>there's probably a good argument for using immutable records for something like that
<taw10>Arguably it doesn't matter, because the real representation should be abstracted away anyway? Start with a single cons cell, then switch to something like a GOOPS class if/when you realise that you want to have other ways of accessing the value, e.g. polar coordinates (c.f. SICP section 2.4)?
<RhodiumToad>hmm. the docs say that immutable records can't be mutated even via struct-set!, but the code says they can be
<RhodiumToad>define-immutable-record-type is a bit simpler than defining your own set of abstract accessors for a cons cell
<RhodiumToad>of course for two dimensions you could also just use a complex number
<ArneBab>emestee: '(x . y) uses less memory than '(x y) or a two-element record, you might want to benchmark (1 . 2) and the record.
<ArneBab>simple starting point:
<ArneBab>,time (let loop ((s 100000000) (v '(1 2 3 . 4))) (when (not (zero? s)) (cdr (cdr (cdr v))) (loop (- s 1) v)))
<ArneBab>(import (srfi srfi-9))
<ArneBab>(define-record-type <v> (v a b c d) v? (a va) (b vb) (c vc) (d vd))
<ArneBab>,time (let loop ((s 100000000) (vt (v 1 2 3 4))) (when (not (zero? s)) (va vt) (loop (- s 1) vt)))
<ArneBab>emestee: '(x . y) uses less memory than '(x y) or a two-element record, you might want to benchmark (1 . 2) and the record.
<ArneBab>simple starting point:
<ArneBab>,time (let loop ((s 100000000) (v '(1 2 3 . 4))) (when (not (zero? s)) (cdr (cdr (cdr v))) (loop (- s 1) v)))
<ArneBab>(import (srfi srfi-9))
<lampilelo>just use dpaste or something like that
<ArneBab>lampilelo: if it had been more lines, I would have. for 4 lines I prefer having them in the history
<lampilelo>the formatting though...
<emestee>thanks I am going to experiment with this
<emestee>I assume cdr for a tuple would be slightly faster too?
<chris>emestee: profiling is the only way to answer. guile devs will usually optimize code iff profiling supports it.
<chris>mostly you'd be better off using a srfi-9 record
<chris>(for code readability)
<ArneBab>emestee: (cdr '(a . b)) => b; (car (cdr '(a b)) => b ; that is the speed difference
***mattrw is now known as mwette
***zap1 is now known as zap
<lampilelo>was this missed by the maintainers?
<lampilelo>IF it's confirmed to work, seems like a no-brainer, the person that posted it will probably use it
***even2 is now known as even
<dsmith>lampilelo: Never heard of arc before. Is it old?
***KindOne_ is now known as KindOne
***KindOne_ is now known as KindOne
<stis>Hello guilers!
<apteryx>what could couse such autoload failures? ;;; Failed to autoload %precious-signals in (shepherd service):
<apteryx>;;; In procedure resolve-interface: no binding `%precious-signals' in module (shepherd service)
<sneek>Welcome back civodul, you have 2 messages!
<sneek>civodul, apteryx says: hey! I was wondering what happens with autoloaded modules w.r.t. to 'source-module-closure'? Seems they might not be added? I've been debugging a problem when I lazy bind (shepherd service) and something seems amiss.
<sneek>civodul, apteryx says: ah, I see extract-dependencies in (guix modules) has a case to cover #:autoload
<civodul>apteryx: that suggested the (shepherd service) module that was loaded lacks '%precious-signals'
<civodul>maybe because it comes from an older version?
<civodul>'source-module-closure' takes #:autoload into account
<apteryx>could be, I'm replaying a service start slot 'by hand' with my root user, it's not exactly a tightly controlled environment
<civodul>note the default #:select? of source-module-closure, though
<civodul>heh, i love that kind of debugging
<civodul>adventure and risks :-)
<apteryx>I wanted to do the same in a VM corresponding to the right environment, but prevents SSH'ing, so I'm struggling to debug :-)
<civodul>the qemu syntax for port forward is terrible
<apteryx>the qemu syntax *for anything* I'd add ;-)
<civodul>ffmpeg too
<apteryx>it seems purely designed as the low-level engine of higher level interfaces such as virt-manager, and it shows
<civodul>(funnily, both started by the same person :-))
<civodul>so i'd copy the syntax from our <virtual-machine> code
<civodul>which is Known Good
*apteryx checks
<apteryx>seems strictly equivalent; mmh
<apteryx>perhaps QEMU is sensitive to the order in which options are given