Gambit-list Septembre 2007

gambit-list@iro.umontreal.ca

25 participants
37 discussions

Using Termite + Snow
by andrew cooke 25 Sep '07

25 Sep '07

[Not sure whether to use Gambit or Snow list - hope duplication not a problem] I have just installed Gambit (4.0.1), Termite (tarball) and Snow (1.1.1). Things seem OK, in that the following works: > gsi Gambit v4.0.1 > (self) #<thread #1 primordial> So I then defined the following in a Snow package: (cond-expand (gambit (define (acu-pmap f lst) (let ((parent (self))) (map (lambda (pid) (recv ((,pid reply) reply))) (map (lambda (x) (spawn (lambda () (! parent (list (self) (f x)))))) lst))))) (else (define (acu-pmap f lst) (map f lst)))) However, when I try to use code that calls acu-pmap I get the error (line 30 is the "let"): *** ERROR IN ac-utils/v1#acu-pmap, "ac-utils.scm"@30.20 -- Unbound variable: ac-utils/v1#self Can anyone suggest why this doesn't work and/or how I can fix it? Thanks, Andrew

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FFI, returning values, thread safety
by Michael South 19 Sep '07

19 Sep '07

I have a question about the C interface. It appears necessary to decrement the reference count of ___STILL objects before returning them: ___SCMOBJ foo() { ___SCMOBJ result; ___EXT(___CHARSTRING_to_SCMOBJ) ("hello", &result, 0); ___release_scmobj (result); return result; } Why is there not a race condition between decrementing the reference count (___release_scmobj) and returning the result? What if another thread wakes up the GC in the meantime? -- Michael South <msouth(a)msouth.org>

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Gambit-C v4.0.1
by Marc Feeley 18 Sep '07

18 Sep '07

Earlier today Gambit-C v4.0.1 was released, in source form and prebuilt binaries. The changelog, which should have been included in the announcement, is available here: Changelog: http://www.iro.umontreal.ca/~gambit/repo/gambit/?shortlog This release includes a change to the Gambit compiler for implementing the continuation-capture, continuation-graft and continuation-return procedures (which are explained in this paper http://citeseer.ist.psu.edu/cache/papers/cs/23888/ http:zSzzSzkaolin.unice.frzSzScheme2001zSzarticlezSzfeeley.pdf/a- better-api-for.pdf). Because of this compiler change, it is tricky to build v4.0.1 using v4.0.0. The best approach is simply to build the system from the v4.0.1 sources. If you insist on building v4.0.1 using v4.0.0 you need to follow these steps: hg pull hg update -r d0020ceaf919 make bootstrap hg update -r v4.0.1 make clean ./configure make The "hg update -r d0020ceaf919" updates the sources of the Gambit compiler so that it is able to compile the runtime system for v4.0.1 (d0020ceaf919 is the id of the changeset with the description "[COMPILER CHANGES NEEDED FOR v4.0.1]..."). The "hg update -r v4.0.1" updates the sources to version v4.0.1. A "make clean" is required because all .c files must be regenerated from the .scm files using the updated compiler. The "./configure" is required because some of the .in files, in particular include/gambit.h.in, have changed and must be processed to generate include/gambit.h etc. Marc

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Gambit C Interface (FFI)
by Guillaume Cartier 16 Sep '07

16 Sep '07

Help needed! I am trying to understand Gambit's C interface and I have this very simple code to allocate a C structure that crashes and have no clue why. Anyone has any idea? (Gambit 4.0.0) (PS: sorry for the double post I forgot you had to post on a registered email else you're awaiting moderator approval) With this function defined in my gambcini : (define (C . rest) (let loop ((n (if (null? rest) 1 (car rest)))) (if (> n 0) (begin (write n) (newline) (compile-file "c") (load "c") (make-S2) (loop (- n 1)))))) I run (C 50) maybe a couple times and always end up getting a random crash often the first time File c.scm : (c-declare "struct S2_ { int x; int y; }; typedef struct S2_ S2;" ) (c-define-type S2 (type "S2")) (define make-S2 (c-lambda () S2 "___result_voidstar = calloc(1, sizeof(S2));"))

1 0

Gambit C Interface (FFI)
by Guillaume Cartier 16 Sep '07

16 Sep '07

Help needed! I am trying to understand Gambit's C interface and I have this very simple code that crashes and have no clue why. Anyone has any idea? (Gambit 4.0.0) With this function defined in my gambcini : (define (C . rest) (let loop ((n (if (null? rest) 1 (car rest)))) (if (> n 0) (begin (write n) (newline) (compile-file "c") (load "c") (make-S2) (loop (- n 1)))))) I run (C 50) maybe a couple times and always end up getting a random crash often the first time File c.scm : (c-declare "struct S2_ { int x; int y; }; typedef struct S2_ S2;" ) (c-define-type S2 (type "S2")) (define make-S2 (c-lambda () S2 "___result_voidstar = calloc(1, sizeof(S2));"))

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Emailing changes automatically
by Marc Feeley 12 Sep '07

12 Sep '07

I would like to automatically send to the Gambit mailing list all the changes that are made to the Gambit repository. I tried following the instructions in: http://morecode.wordpress.com/2007/08/03/setting-up-mercurial-to-e- mail-on-a-commit/ but that doesn't seem to work. Does anyone here have experience with doing that? The .hg/hgrc file I'm using is attached below. Marc [paths] default-push = ssh://gambit@trex.iro.umontreal.ca/HTML/repo/gambit default = http://www.iro.umontreal.ca/~gambit/repo/gambit/ [extensions] hgext.notify = [hooks] # batch emails when many changesets incoming at one time changegroup.notify = python:hgext.notify.hook [smtp] host = localhost [email] from = gambit(a)iro.umontreal.ca [web] baseurl = http://www.iro.umontreal.ca/~gambit/repo/gambit/ [notify] # config items go in here config = /part/02/www-perso/usagers/gambit/HTML/repo/notify.conf maxdiff = 0 # max lines of diffs to include (0=none, -1=all) maxsubject = 67 # truncate subject line longer than this diffstat = False # add a diffstat before the diff content sources = serve push pull bundle # notify if source of incoming changes in this\ list # you can override the changeset template here, if you want. # If it doesn't start with \n it may confuse the email parser. # here's an example that makes the changeset template look more like hg log: template = \ndetails: {baseurl}{webroot}/rev/{node|short} \nchangeset: {rev}:{\node|short}\nuser: {author}\ndate: {date|date}\ndescription:\n{desc}\\n Note that the file /part/02/www-perso/usagers/gambit/HTML/repo/ notify.conf contains: [reposubs] # key is glob pattern, value is ","-separated list of subscriber emails * = feeley(a)iro.umontreal.ca # [usersubs] # # key is subscriber email, value is ","-separated list of glob patterns # user@host = pattern # # [reposubs] # # key is glob pattern, value is ","-separated list of subscriber emails # pattern = user@host

3 2

'const' types with ffi
by David St-Hilaire 12 Sep '07

12 Sep '07

Hi all! How can I represent a 'const int' type within gambit's ffi? Lets say I have the C funciton: const int adder(int n){ blablabla...} and I want to interface that function with a c-lambda, how can I do that? If I try to omit the 'const' for the parameter's type, I get an error (bad type convertion) when compiling with g++ ("invalid conversion from ‘const void*’ to ‘void*'")... I haven't seen anything talking about 'const' types in the ffi documentation... By the way, I'd like to thank you all for always answering and answering quickily to all my (and others) questions! It really helps and motivates me to program in scheme! ^_^ David

2 1

C macro ffi?
by David St-Hilaire 12 Sep '07

12 Sep '07

Hi again! Is there a way to interface some C defined macros? I tried with c-lambda and was unsucessfull... Thanks! David

1 0

[ANN] Gambit-C v4.0.1 released
by gambit＠iro.umontreal.ca 12 Sep '07

12 Sep '07

Gambit-C v4.0.1 is now available. The sources and prebuilt distributions can be obtained from the Gambit web site by visiting one of the following links. sources: http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/source/gambc-v4_0_… prebuilt: http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.0/prebuilt/gambc-v4_…

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Screensaver .gif
by Bradley Lucier 11 Sep '07

11 Sep '07

Just for fun, I made this the only image in my screensaver folder on my mac at work. I unclicked "crop slides to fit on screen" under screensaver options to get the effect I wanted. This is an old PLT logo, previously converted by me to svg in inkscape, and now converted to GIF at a fairly high resolution (.svg - > .eps (by inkscape) -> .gif (by Preview)). Robby Findler has a whole progression of PLT logos on his web site at http://people.cs.uchicago.edu/~robby/logos/ This particular logo seems to have been disavowed by the PLT group in an attempt to go mainstream (good luck with that!), so I don't feel so bad using it as a logo for Scheme itself. So Steve Jobs like to fly the skull-and-crossbones; we can turn a dead-head into a lambda-head! Brad

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Gambit-list Septembre 2007