Gambit-list Septembre 2007

gambit-list@iro.umontreal.ca

25 participants
37 discussions

Pattern matching in gambit
by Phil Dawes 04 Sep '07

04 Sep '07

Hi Gambit List, I was wondering, what do people use for pattern matching (in the ML sense) in gambit. Is there a port of plt's match.ss for gambit? I found this[1] which works ok, but am I missing something else? Many thanks, Phil [1] http://schemecookbook.org/Cookbook/MacroExampleASimplePatternMatcher

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difference between "console" and "stardard-in"?
by naruto canada 03 Sep '07

03 Sep '07

hi I've been working on a simple interpeter, I've tried hard to make it meta-circlar. One strange thing is, If I copy and paste the interpreter code from another console, then it world work, or if I use (load "mc-eval.sc") it also works, but it fails with some mysterious reason if I "cat" the code in like: cat mc-eval.sc| /usr/v4.0.0/bin/gsi mc-eval.sc What is the difference the console and standard-in? (or "load") (I am fairly sure the code is working, I can stack the interpreter at least 4 times before it slows down) Thanks.

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Debugging threadded applications
by Phil Dawes 03 Sep '07

03 Sep '07

Hi Marc, Hi Gambit list, I've been experimenting with termite and was wondering what facilities there were for debugging gambit threads. For example, when a thread hangs waiting on some IO, is there a way I can find it and interrupt it from the REPL on the primordial thread? Is there any way of getting a list of the current threads, and maybe a stack trace for each? Any tips greatly appreciated, Cheers, Phil

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How to compile large one-file programs with small RAM size?
by Sven.Hartrumpf＠FernUni-Hagen.de 03 Sep '07

03 Sep '07

Hi all. Does anybody have any hints how to compile a large one-file program (10K - 100K lines) on a machine with only 3 GB RAM? (Splitting the file is no option because it would hurt performance of the compiled program so much that I would better stick with other Scheme compilers; I am extrapolating here from Gambit 3.0 to Gambit 4.0.) Some details: - gcc 4.2.1, Linux, 32bit - gsc command: > gsc n.scm virtual memory exhausted: Cannot allocate memory memtime reports: 412.94 user, 20.03 system, 470.08 elapsed -- Max VSize = 2331356KB, Max RSS = 2001108KB - my 'declare': (declare (r5rs-scheme) (block) ;(inline) ;(inlining-limit 500) ;(lambda-lift) ;(constant-fold) (standard-bindings) (extended-bindings) (not safe) (not interrupts-enabled) (generic) (mostly-fixnum) ) Greetings Sven

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Re: [gambit-list] compiler bug?
by Marc Feeley 03 Sep '07

03 Sep '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 25-Sep-06, at 3:48 PM, Sven.Hartrumpf(a)FernUni-Hagen.de wrote: > Hello Marc. > > I have a large program which behaves a little different > with gsc than any other Scheme I know of (bigloo, chicken, gauche): > Here is the problematic region: > > (let* ((orth (and (pair? word-info) > ;(not (eq? (caar word-info) 'words)) > (fs-value (car word-info) '(orth)))) > (orth-l (if orth (string-length orth) 0)) > (left-hyphen (and (> orth-l 2) > (char=? (string-ref orth 0) # > \-))) ; examples: \quw{Steuergesetzgebung und -verwaltung}, \quw > {auspringen und -setzen} > (right-hyphen (and (> orth-l 1) > (char=? (string-ref orth (- orth- > l 1)) #\-))) > (step (if left-hyphen > (and (not right-hyphen) > -1) > (and right-hyphen > 1)))) > > left-hyphen and right-hyphen are evaluated to #f for some binding - > this > is as expected. But step is bound to 1 which seems wrong to me. > Minimizing the problem might be hard for me, so I hope that you can > see > the problem already :-) > > Ciao > Sven Sven, you have just uncovered a nasty bug in the compiler. In beta 18 the transformation for the "and" form is too aggressive in the case where the second argument is a constant. As far as I can tell this bug was introduced just before beta 18 was released. Surprisingly in the 70Kloc in the Gambit runtime system and compiler this case does not occur. I have now fixed the bug and will release beta 19 shortly because this is a serious bug. Thanks! Marc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) iD8DBQFFGEqS//V9Zc2T/v4RAqTeAJ9asp7elGoK7yqa6MzmLFTRj6K8UwCfc3d4 5haROCNvlgMs1NREyZCgYIw= =bvLI -----END PGP SIGNATURE-----

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how to make write display (quote 1 2 3) instead of '(1 2 3)
by naruto canada 02 Sep '07

02 Sep '07

hi how to make write display (quote 1 2 3) instead of '(1 2 3)

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redefining symbols with 'load'?
by James Long 02 Sep '07

02 Sep '07

I want to make sure I understand how 'load' works in Gambit. I have basic build system using a slightly modified version Snow up and running, and I'm making a few assertions that I want to make sure are true. In Gambit, a 'load' and 'include' are obviously quite different because it's using machine-compiled code for compiled objects, not bytecode. I have heard (I have not tested this yet, although I will soon) that it's quite expensive to call code across module boundaries, which makes reasonable sense because it cannot simply use the 'goto'-style jump. So, for any high-performance application, you want to inline code when compiling if you don't need a shared library. Now, I have my system separated into a few shared libraries (.o1 files), but there are cases when I want to inline code that is common between them. For example, I have a utilities package which is called quite often in all of the modules, and it makes sense to include this file rather than load it (for performance). However, doing so would include this file in all modules, so when the modules are loaded together, the same symbols are redefined. If code is of the form (load "lib") (include "util.scm") (call-utility-function 'with 'some 'params) and util.scm is also included in the "lib" library, is it same to assume that when the above code is compiled in Gambit that call-utility-function with resolve to the local version with a 'goto'-style jump? I don't see how it wouldn't since it has no idea about lib's version of call-utility-function until run-time, unless it does some sort of check at runtime? I know you can't redefine symbols in Gambit at compile-time, so I'm assuming it does a sort of static binding. I'll be the first to admit that this may be a major case of pre-optimization. so slap me if I shouldn't be worrying about this as much.

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Gambit-list Septembre 2007