August 2009 - Gambit-list - mailman.iro.umontreal.ca

[ANN] scheme-reports.org
by Marc Feeley 21 Aug '09

21 Aug '09

[Apologies if you get duplicates of this message.] This message is being posted to various lists to inform members of the Scheme community on the activities of the Scheme Language Steering Committee which is overseeing the process of Scheme language evolution. A website has been setup to publish various documents pertaining to our activities. The steering committee will be presenting and discussing these documents at the Scheme workshop on August 22. Our hope is that by publishing them now, a more fruitful question period will ensue at the workshop. The website URL is: http://www.scheme-reports.org/ The documents being published today are: 1) The amended Scheme Language Steering Committee charter. 2) The steering committee's position statement on Scheme language evolution. 3) A draft of the working group meta charter, that describes how working groups are run. 4) A draft of the charter for working group 1, which will be involved in the elaboration of a specification for a "small" Scheme language. 5) A draft of the charter for working group 2, which will be involved in the elaboration of a specification for a "large" Scheme language. If you would like to comment on these documents, we urge you to come to the Scheme workshop and/or to send email to the steering committee at this address: sc(a)scheme-reports.org . Will Clinger Marc Feeley Chris Hanson Jonathan Rees Olin Shivers

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How to create small standalone executable with Gambit-C?
by peter lo 18 Aug '09

18 Aug '09

Dear all, I am new to Gambit-C. I keep hearing that with Gambit-C, it is easy to create small executable. But when I tried, a simple hello world program takes around 3 MB when compiled as a STANDALONE executable. Is there a way to create small executable which includes only used functions, just like in C, we don't link the whole library into the executable. Thanks. Peter Yahoo!香港提供網上安全攻略，教你如何防範黑客! 請前往 http://hk.promo.yahoo.com/security/ 了解更多!

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Black Hole
by Marcelo Alvim 17 Aug '09

17 Aug '09

Hi, I am new to Gambit (and Scheme as a whole), and I'm trying to install Black Hole with no success so far. I've tried following the instructions in http://dynamo.iro.umontreal.ca/~gambit/wiki/index.php/Black_Hole, but whenever I try to clone http://mwaza.dyndns.org/apps/files/modules.git I get a timeout. If I try git://repo.or.cz/blackhole.git I get an empty repo. Does anyone know if Black Hole is still going and, if so, where to get it? Thanks, Marcelo.

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Gambit in Emacs: REPL interaction
by FFT 17 Aug '09

17 Aug '09

Hi I tried to use Emacs as suggested in the manual, and I also tried the Quack mode. Either I'm not using them right, or they just don't provide the functionality I need. I'm not looking for something as advanced as SLIME necessarily (which AFAIK only works with Scheme48), but at least something like what you get with ELISP: When you are editing a file, and eval an expression to the REPL, you get an answer in the minibuffer (which should temporarily expand if necessary) Also, if there is an error, you get a kind of pop-up window that's easy to dismiss and get to the top level of the REPL. I don't get these with Quack or Gambit mode. How do you make this work with Emacs? Commercial IDEs ruined this for me.

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macro vs runtime environment
by lowly coder 15 Aug '09

15 Aug '09

why is: (load "t1.scm") (define x 20) valid, where as: (define-macro (foo) (load "t1.scm") (define x 20)) result in a ill-placed define error? I was under the impression that scheme define-macro was just scheme code; it appears that the environment the macro is run in is different from the runtime ones? Thanks!

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Re: [gambit-list] Video game written in Gambit
by David Rush 15 Aug '09

15 Aug '09

ummm....I found a bug :) in action mode spin the cube so fast that the quantz all remain floating while a new quantz comes in. I eventually ended up with a stuck sprite in the middle of the screen... -- GPG Public key at http://cyber-rush.org/drr/gpg-public-key.txt

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why does load/include work differently for this function?
by lowly coder 15 Aug '09

15 Aug '09

~/test:$ cat lookup-var.scm (define (lookup-var var-name) (##define-macro (macro-code-cte c) `(##vector-ref ,c 2)) (##define-macro (macro-rte-up rte) `(##vector-ref ,rte 0)) (define (the-env) (##continuation-capture (lambda (cont) (if (##interp-continuation? cont) (let (($code (##interp-continuation-code cont)) (rte (##interp-continuation-rte cont))) (cons (macro-code-cte $code) rte)) (error "the-env must be called from interpreted code"))))) (define (env-ref env var) (let loop1 ((c (car env)) (r (cdr env))) (cond ((##cte-top? c) (##global-var-ref (##make-global-var var))) ((##cte-frame? c) (let loop2 ((vars (##cte-frame-vars c)) (i 1)) (if (pair? vars) (if (eq? var (##car vars)) (vector-ref r i) (loop2 (cdr vars) (+ i 1))) (loop1 (##cte-parent-cte c) (macro-rte-up r))))) (else (loop1 (##cte-parent-cte c) r))))) (env-ref (the-env) var-name)) ~/test:$ cat test.scm (define-macro (foo) (define x 20) (load "./lookup-var") (pp `(foo ,(lookup-var 'x)))) (define-macro (bar) (define x 20) (include "./lookup-var.scm") (pp `(bar ,(lookup-var 'x)))) (foo) (bar) ~/test:$ gsi test.scm (foo #!unbound) (bar 20) note that lookup-var is just a function ... i'm surprised that load/include gives me different results

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.gambcini vs included files
by lowly coder 14 Aug '09

14 Aug '09

~/test:$ cat ../.gambcini (define-macro (bar#fun2 foo) ''(yay)) (pp 'loaded-gambcini) ~/test:$ cat test.scm (define-macro (bar#fun x) (if (equal? x cons) 1 2)) (##namespace ("foo#")) (##namespace ("" pp load)) (pp (bar#fun '+)) (load "t1.scm") ~/test:$ cat t1.scm (pp (bar#fun2 '-)) (pp (bar#fun '-)) ~/test:$ gsi test.scm loaded-gambcini 2 (yay) *** ERROR IN "t1.scm"@2.6 -- Unbound variable: bar#fun ~/test:$ Here's what confuses me -- the macro defined in ~/.gambcini is accessible, but the one in test.scm is not. What 'environment' are the functions/macros in ~/.gambcini defined in? [And how can I at run time throw stuff in there]. Thanks!

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syntax-case and keywords
by Derrell Piper 14 Aug '09

14 Aug '09

Hi, I'm porting some Lisp to Scheme and I've run into a problem trying to use both extended parameter lists (keywords) with syntax-case. % cat test.scm (define (s #!key (f "foo") (v #f)) #t) % gsi test % gsi -e '(load "~~lib/syntax-case")' test *** ERROR IN ##call-with-values -- invalid syntax (define (s #!key (f "foo") (v #f)) #t) The actual code has both define-syntax and define-macro definitions. The manual says that define-syntax doesn't support special forms that are specific to Gambit, so I'm assuming that's the real issue here. But I'm wondering what the philosophy of Gambit is with respect to macros, given that define-syntax was specified for both R4RS and R5RS. Chicken 4 deprecated the use of define-macro and now forces one to use define-syntax. Which is ironically why I have define-syntax forms, in that I ported this code to Chicken first. Should I just rewrite them as define-macro? For all it's faults, CL only has one macro form. :-)

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Retrieving both key and value from table
by Alex Queiroz 14 Aug '09

14 Aug '09

Hallo, In a table I am using keys which are structures defined with define-type. Since some of the fields have the equality-skip: modifier, the key that I pass is not the same as the key stored in the table. I have taken a look in sys.scm and it seems I could hack a solution using ##table-access. Is this the best way to do this? I could also store a pair as the associated value in the hash table, but I'd like to avoid consing. Speaking about consing, is there a way to limit the growth of the hash table to a certain bound? Thanks, -- -alex http://www.ventonegro.org/

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