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Blackhole for Android
by Álvaro Castro-Castilla 25 Jan '12

25 Jan '12

Hi! Finally I got Blackhole working for Android. For those interested, I'm developing a tiny framework for making games in Android (plus other platforms) using Gambit and the Blackhole module system. If you want to give it a try: https://github.com/alvatarc/anygame You'll need to use my fork of Blackhole, which is pending Per's review before pulling into his master branch: https://github.com/alvatarc/blackhole Basically, what this fork allows is a special flag --to-c (or -C) : bh exe -C main.scm this allows compilation of all needed modules to c, plus the link file. It also outputs the generated files' path to stderr in case you need this information. Please, let me know if you find any errors or mistakes, I'll be happy to fix and help. Best regards, Álvaro Castro-Castilla

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Question on "buffering:" option for vector-port
by Meng Zhang 24 Jan '12

24 Jan '12

I expect the reading option may block the thread with "buffering: #f". For example: (let ((chan (open-vector '(buffering: #f)))) (thread-start! (make-thread (lambda () (write "Value" chan) (pp "Write done")))) (thread-start! (make-thread (lambda () (thread-sleep! 1) (pp "Start reading") (pp (read chan))))) (thread-sleep! 5)) My expectation: Outputs: "Start reading" "Write done" or "Value", in any order. Result for 4.6.3, osx 10.6.7: Outputs: "Write done" "Start reading" "Value" Obviously, the "read" option doesn't block the spawned thread even "buffering" is set to #f. Did I misunderstand it? -- Meng Zhang Sent with Sparrow (http://www.sparrowmailapp.com/?sig)

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Back to trying to figure out blackhole
by Hendrik Boom 24 Jan '12

24 Jan '12

In http://dynamo.iro.umontreal.ca/~gambit/wiki/index.php/Black_Hole it says Make sure you put the blackhole-libs into a directory called "std" in ~~/ lib/modules I find this sentence unclear. Not being a regular Gambit user yet, I don't know where ~~ is. I've got a /usr/local/Gambit-C/v4.6.3/lib. Am I supposed to create modules in there and copy the contents of blackhole-libs into it? Or copy the directory blackhole-libs in as a sudirectory of modules? -- hendrik

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Re: [gambit-list] slime (swank) and gambit
by Marc Feeley 23 Jan '12

23 Jan '12

On 2012-01-19, at 6:37 PM, Steve Graham wrote: > Nice picture. > > What is picobit? > > > Steve Sorry, that message wasn't meant for the whole list... But given that you ask, picobit is a Scheme compiler for a very compact VM that I wrote a few years ago for embedded applications. Here's the paper Vicent St-Amour and I published at IFL09 (it won the "best paper award"): http://www.iro.umontreal.ca/~feeley/papers/StAmourFeeleyIFL09.pdf Marc

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Re: [gambit-list] Idiomatic Scheme
by Roger Wilson 19 Jan '12

19 Jan '12

Hi, Thanks for all the input guys. It all makes sense. I have a question on the cond/case option though. More one for StackOverflow really but... (define (make-f) (lambda (message . arguments) (case message (('get!) (display "get")) (('size) (display "size")) (else (display "no match"))))) (define f (make-f)) (f 'size) > "no match" (define (make-g) (lambda (message . arguments) (display message) (newline) (cond ((eq? message 'get!) (display "get")) ((eq? message 'size) (display "size")) (else (display "no match"))))) (define g (make-g)) (g 'size) > "size" How do I get the make-f variant using case to do what I want? I guess this is a eqv? vs eq? thing, or am I missing a quote somewhere? Thanks, Roger. > > ---------- Forwarded message ---------- > From: "Adrien Piérard" <pierarda(a)iro.umontreal.ca> > To: Mikael <mikael.rcv(a)gmail.com> > Cc: gambit-list(a)iro.umontreal.ca > Date: Thu, 19 Jan 2012 21:50:29 +0900 > Subject: Re: [gambit-list] Idiomatic Scheme > Hi again, > > I couldn't resist answering more :) > > >> In particular I'm unhappy with the way the message arguments are > accessed as (car arguments) rather than by explicit name. I can see that > being a potential cause of bugs if the number of arguments grows and they > vary with each message. > > You'll probably enjoy optional parameters, then, even though my code > sample is not really portable extensible: > > (lambda (message #!optional arg1) > (case message > ((:put-name!) > (push (make-blob-name arg1) unused-name-list) > (randomise-list)) > ...)) > > By the way, why sort the list? > Why not also let the constructor of your data type assign the random value? > I barely use DEFINE-TYPE, but I guess there's a way to make the > constructor call a function to generate the random value or something > like that. > Unfortunately, (random init: (random-integer 42)) doesn't work. > > > maybe switch the cond to a case? > > Indeed, that too. > > P! > -- > Français, English, 日本語, 한국어 > > > _______________________________________________ > Gambit-list mailing list > Gambit-list(a)iro.umontreal.ca > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list > >

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Idiomatic Scheme
by Roger Wilson 19 Jan '12

19 Jan '12

Hi, I'm still using Gambit Scheme from time to time and having a lot of fun with it. I've a newbie question however, I'm trying to figure out the best way to structure code. With that in mind are there any comments on the following code? I'm trying to create an 'object' that holds a list of names, can return a random one on request that can later be returned to it. What's the proper Scheme way of doing this kind of thing? Here's my stab, it returns a function that then accepts 'messages' as parameters.... (define (make-name-list seed-names) ;; The type the list is built from (define-type blob-name name (random init: 0)) ; Used for sorting (let ((unused-name-list '())) (define (randomise-list) ; Assign each name a random number and then sort them (map (lambda (x) (blob-name-random-set! x (random-integer 65536))) unused-name-list) (sort! unused-name-list (lambda (x y) (if (< (blob-name-random x) (blob-name-random y)) #t #f)))) ;; Put all the seed names in the list (map (lambda (x) (push (make-blob-name x) unused-name-list)) seed-names) (lambda (message . arguments) (cond ((eq? message ':get-name!) (if (null? unused-name-list) "No names available" (begin (let ((name (blob-name-name (car unused-name-list)))) (set! unused-name-list (cdr unused-name-list)) name)))) ; Add a name to the list, used to return names once they're no longer needed ((eq? message ':put-name!) (push (make-blob-name (car arguments)) unused-name-list) (randomise-list)) ; Debug, print the internal display ((eq? message ':display) (display unused-name-list)) (else (error 'name-list "unrecognized message")))))) ;; Test drive code....... (define name-list (make-name-list (list "Albert" "Bruce" "Clive"))) (display (name-list ':get-name!)) (name-list ':put-name! "David") (name-list ':put-name! "Edgar") (name-list ':put-name! "Frederick") (display (name-list ':display)) Some points: In particular I'm unhappy with the way the message arguments are accessed as (car arguments) rather than by explicit name. I can see that being a potential cause of bugs if the number of arguments grows and they vary with each message. I realise that the randomise-list function is probably called too often and maintaining a 'dirty bit' would allow it to be only called when necessary when getting a name. I've years of C/C++ programming behind me, which is probably readily apparent. How can I improve the code? Thanks, Roger.

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[ANN] Gambit-C v4.6.3 released
by gambit＠iro.umontreal.ca 19 Jan '12

19 Jan '12

Gambit-C v4.6.3 is now available. Changelog: http://www.iro.umontreal.ca/~gambit/repo/.cgit.cgi/Gambit/log/ 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/v4.6/source/gambc-v4_6_… (for typical users) http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/source/gambc-v4_6_… (for developers) prebuilt: http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/prebuilt/gambc-v4_… http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/prebuilt/gambc-v4_…

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Re: [gambit-list] [ANN] Gambit-C v4.6.3 released
by Marc Feeley 19 Jan '12

19 Jan '12

On 2012-01-19, at 11:39 AM, Jeff Read wrote: > Shoot, I have a 64-bit machine... :) The code I sent works on x86-64. The x86 assembler works for both x86-32 and x86-64, so it covers all bases. Marc

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Strange side effect after redefinition of apply
by Sascha Ziemann 17 Jan '12

17 Jan '12

I got a strange side effect with my silex apply hack. I was able to simplify it down to this test case where I define the two macros apply and token. The file a.scm works: $ cat a.scm (define gambit-apply apply) (define-syntax apply (syntax-rules (string-append) ((_ string-append list) (append-strings list)) ((_ func list) (gambit-apply func list)))) (display (gambit-apply string-append (list "a"))) (newline) $ gsi -:s a.scm a The file b.scm works also: $ cat b.scm (define-syntax token (syntax-rules () ((_ name value) (cons name value)) ((_ name) (cons name '())))) (define (b) (token "b")) (display (car (b))) (newline) $ gsi -:s b.scm b But when I concatenate the two files I get an error: $ cat a.scm b.scm > c.scm $ gsi -:s c.scm *** ERROR IN #<procedure #2>, "c.scm"@7.7 -- Unbound variable: gambit-apply How could gambit-apply get lost?

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shell-command failing in Gambit 4.6.2 (MinGW build)
by REPLeffect 17 Jan '12

17 Jan '12

The shell-command procedure under the MinGW build of Gambit 4.6.2 seems to be broken. When running gsi under the MinGW MSys shell (by running gsi.exe -:d-), things worked fine under Gambit 4.6.0 (as shown below). However, in Gambit 4.6.2, it appears that only the program name passed in the shell command is being recognized. Thus, I could run (shell-command "ls 1 2 3") while in a directory where no such files existed, and I got the contents of the directory (as if the command had only been "ls", with no arguments). ==== Output running under Msys: (gsi.exe -:d-) ========== Gambit v4.6.0 > (shell-command "ls 1 2 3") ls: 1: No such file or directory ls: 2: No such file or directory ls: 3: No such file or directory 512 > Gambit v4.6.2 > (shell-command "ls 1 2 3") INSTALL.txt LGPL.txt LICENSE-2.0.txt README bin config.guess config.log config.status config.sub configure configure.ac doc examples gsc gsc-comp.exe gsi include install-sh lib makefile makefile.in misc mkidirs prebuilt relpath tests 0 > The results get even worse when running Gambit 4.6.2 directly from the Windows start menu. Here again, version 4.6.0 does what I expected. However, when I run version 4.6.2, I can't get the shell-command to work no matter what command I pass it: ====== Output running gsi.exe directly from the Windows Start Menu: ====== Gambit v4.6.0 > (shell-command "dir 1 2 3") Volume in drive C has no label. Volume Serial Number is 14C2-1C72 Directory of C:\test\Gambit-C\v4_6_0\v4.6.0\bin Directory of C:\test\Gambit-C\v4_6_0\v4.6.0\bin Directory of C:\test\Gambit-C\v4_6_0\v4.6.0\bin File Not Found 256 > Gambit v4.6.2 > (shell-command "dir 1 2 3") *** ERROR IN (console)(a)1.1 -- No such file or directory (open-process '(path: "sh" arguments: ("-c" "dir 1 2 3") stdin-redirection: #f stdout-red... ) 1> > (shell-command "dir") *** ERROR IN (console)(a)5.1 -- No such file or directory (open-process '(path: "sh" arguments: ("-c" "dir") stdin-redirection: #f stdout-redirecti... ) 1> -------------------------------------------------------------- All of these tests were run against the current prebuilt versions of Gambit 4.6.0 and 4.6.2 downloaded from Gambit's web site. I'll be happy to test any patches or other changes needed to fix this problem.

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