July 2012 - Gambit-list - mailman.iro.umontreal.ca

Edge triggered I/O with libevent
by Adam Langley 04 Apr '13

04 Apr '13

Gambit uses the select call on POSIX systems to multiplex IO operations. This is fine for small numbers of file descriptors, but falls apart quickly with large numbers[1]. libevent[2] is a wrapper library around a number of modern IO multiplexing systems (epoll on Linux, kqueue on the BSDs as well as poll and select). Attached is a patch which converts Gambit to using edge triggered I/O with epoll and libevent. This also requires a patch (attached) of libevent since the standard distribution doesn't include edge triggering support and the upstream appears to be on holiday. (epoll is required because I don't have a BSD box on which to develop edge triggering support for kqueue) This patch (for Gambit) preprocesses away to nothing unless --enable-libevent is passed to the configure script. (Note that, since this patches the configure.ac script, you'll need to run autoconf to regenerate). I hope I've not broken anything, but at this stage I've only tested that the console and tcp ports work. This patch (in the future) should also allow people, who write programs which use socket calls directly, to integrate into the main event loop at some point. Testing is more than welcome and, if you find a form of IO which is broken, please email me. [1] http://monkey.org/~provos/libevent/libevent-benchmark2.jpg [2] http://monkey.org/~provos/libevent/ -- Adam Langley agl(a)imperialviolet.org http://www.imperialviolet.org (+44) (0)7906 332512 PGP: 9113 256A CC0F 71A6 4C84 5087 CDA5 52DF 2CB6 3D60

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Creating scheme modules with functions callable from C main program
by Andrew Suttles 31 Aug '12

31 Aug '12

Folks - I am writing a simple Windows native app in C using Win32 libraries. I'd like to to have some of my Windows callback functions call routines that I've written (or will write) in GambitC (because scheme is more fun to write and maintain than C). I've found material on how to call functions written in C in the scheme interpreter process, but not the other way around. In other words, when I compile a module of scheme functions into an object file, I don't have a header file to include in my main program written in C. How do I call those scheme functions? Thanks again for the help. I'm fairly new to Scheme and I'm *very new* to GambitC, so please excuse the the naivete of my question. Andrew

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problem with ffi and libxml2
by Cyrille Duret 05 Aug '12

05 Aug '12

hello, I have problem to parse xml string with ffi and libxml2. My code is in the test file libxml-raw.scm : (c-declare #<<end #include <stdlib.h> #include <libxml/xmlreader.h> xmlTextReaderPtr create_reader(const char* buffer, size_t len) { return xmlReaderForMemory(buffer, len, "_.xml", NULL, 0); } int first_type_prime(xmlTextReaderPtr reader) { int type; if( reader != NULL ) { int cont = xmlTextReaderRead(reader); if( cont ) { type = xmlTextReaderNodeType(reader); printf("read %d\n", type); xmlFreeTextReader(reader); return type; } xmlFreeTextReader(reader); return -1; } } int first_type(const char* s, size_t len) { return first_type_prime(create_reader(s, len)); } end ) (c-define-type xmlTextReader "xmlTextReader") (c-define-type xmlTextReaderPtr (pointer xmlTextReader)) (define create-reader (c-lambda (nonnull-char-string unsigned-int) xmlTextReaderPtr "create_reader")) (define first-type-prime (c-lambda (xmlTextReaderPtr) int "first_type_prime")) (define first-type (c-lambda (nonnull-char-string unsigned-int) int "first_type")) Two test functions are defined here : The first-type function take xml body and create the parser within the c body. The first-type-prime uses a pointer on xmlTextReader structure stored and the scheme-side. The first-type-prime function fails and I don't know what's going on : @ gsc-gambit Gambit v4.6.4 > (compile-file "libxml-raw.scm" 'cc-options: "-Wno-write-strings -U___SINGLE_HOST -I/usr/local/include/libxml2" 'ld-options: "-L/usr/local/lib/ -lxml2") "/usr/users/cydu/programming/scheme/modules/xml/libxml-raw.o1" > (load "libxml-raw") "/usr/users/cydu/programming/scheme/modules/xml/libxml-raw.o1" > (define r (create-reader "<xml>toto</xml>" 15)) > r #<xmlTextReader* #2 0x801781300> > (first-type-prime r) _.xml:1: parser error : Char 0x0 out of allowed range <xml ^ _.xml:1: parser error : Couldn't find end of Start Tag xml <xml ^ read 0 0 > while this call works : > (first-type "<xml>toto</xml>" 15) read 1 1 Any idea what's happened ? thanks a lot cyrille

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(shell-command) in android
by Álvaro Castro-Castilla 26 Jul '12

26 Jul '12

Hi, (shell-command) doesn't work properly in Android apparently because it checks for the presence of environment variable HOME and it isn't always defined in this OS. As it doesn't find this variable it chooses CMD.EXE for executing as if it were Windows, which obviously doesn't work. However PATH seems to be in all devices I've checked out. AFAIK it also happens to be present in OsX and all Linux flavours, is that right? Best regards

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Final Call For Papers: Implementation and Application of Functional Languages 2012, Oxford, UK
by Tom Harper 17 Jul '12

17 Jul '12

The deadline for pre-symposium drafts, 30 July, is approaching! IFL has a post-symposium review process, so it is a great chance to submit a draft or extended abstract and get feedback before the review process. ------------------------------------------------------------------------------- CALL FOR PAPERS 24th Symposium on Implementation and Application of Functional Languages (IFL 2012) University of Oxford, UK, August 30-September 1, 2012 http://www.cs.ox.ac.uk/conferences/IFL2012/ This year IFL will be hosted by the University of Oxford, within the idyllic setting of the dreaming spires and picturesque colleges, which have been the home to academic endeavour and research for over nine centuries. The symposium will be held between 30 August and 1 September, 2012. Scope ----- The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2012 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming. Following the IFL tradition, IFL 2012 will use a post-symposium review process to produce formal proceedings which will be published by Springer Verlag in the Lecture Notes in Computer Science series. All participants in IFL 2012 are invited to submit either a draft paper or an extended abstract describing work to be presented at the symposium. Work submitted to IFL must not be submitted simultaneously to other venues; submissions must adhere to ACM SIGPLAN's republication policy: http://www.sigplan.org/republicationpolicy.htm. The submissions will be screened by the program committee chair to make sure they are within the scope of IFL, and will appear in the draft proceedings distributed at the symposium. Submissions appearing in the draft proceedings are not peer-reviewed publications. After the symposium, authors will be given the opportunity to incorporate the feedback from discussions at the symposium and will be invited to submit a revised full article for the formal review process. From the revised submissions, the program committee will select papers for the formal proceedings considering their correctness, novelty, originality, relevance, significance, and clarity. Topics ------ IFL welcomes submissions describing practical and theoretical work as well as submissions describing applications and tools. If you are not sure that your work is appropriate for IFL 2012, please contact the PC chair at ralf.hinze(a)cs.ox.ac.uk. Topics of interest include, but are not limited to: language concepts type checking contracts compilation techniques staged compilation run-time function specialization run-time code generation partial evaluation (abstract) interpretation generic programming automatic program generation array processing concurrent/parallel programming concurrent/parallel program execution functional programming and embedded systems functional programming and web applications functional programming and security novel memory management techniques run-time profiling and performance measurements debugging and tracing virtual/abstract machine architectures validation and verification of functional programs tools and programming techniques (industrial) applications of functional programming Submission details ------------------ Presentation submission deadline: July 30th, 2012 Notification of acceptance: August 1st, 2012 Early registration deadline: August 10th, 2012 IFL 2012 Symposium: August 30-September 1, 2012 Submission for (post) review process: November 30th, 2012 Notification Accept/Reject: February 4th, 2013 Camera ready version: March 18th, 2013 Prospective authors are encouraged to submit papers or extended abstracts to be published in the draft proceedings and to present them at the symposium. All contributions must be written in English, conform to the Springer-Verlag LNCS series format and not exceed 16 pages. The draft proceedings will appear as a technical report of the Department of Computer Science of the University of Oxford. (We are more liberal with the draft proceedings, where longer papers or SIGPLAN 2 column 12 page papers are acceptable. For other formats please contact the chair at ralf.hinze(a)cs.ox.ac.uk. For consideration for the final proceedings, only the 16 page LNCS format will be accepted.) Papers are to be submitted via the conference's EasyChair submission page: https://www.easychair.org/conferences/?conf=ifl2012 Peter Landin Prize ------------------ The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honoured article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 Euros. Programme committee ------------------- Edwin Brady, University of St. Andrews, UK Andrew Butterfield, University of Dublin, Ireland Matthew Flatt, University of Utah, US Andy Gill, University of Kansas, US Stephan Herhut, Intel Labs, Santa Clara, US Ralf Hinze (Chair), University of Oxford, UK Zhenjiang Hu, National Institute of Informatics, Japan Patrik Jansson, Chalmers University of Technology, Sweden Mauro Jaskelioff, Universidad Nacional de Rosario, Argentina Gabriele Keller, University of New South Wales, Australia Simon Marlow, Microsoft Research, UK Pablo Nogueira, Technical University of Madrid, Spain Bruno Oliveira, Seoul National University, Korea José Nuno Oliveira, University of Minho, Portugal Rinus Plasmeijer, Radboud University Nijmegen, Netherlands Tom Schrijvers, Ghent University, Belgium Tim Sheard, Portland State University, US Wouter Swierstra, University of Utrecht, Netherlands Peter Thiemann, University of Freiburg, Germany Simon Thompson, University of Kent, UK Steve Zdancewic, University of Pennsylvania, US

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MeroonV3 cause Xcode random freeze on iPhone real device
by Shihpin Tseng 13 Jul '12

13 Jul '12

I noticed that if run app with MeroonV3 on iPhone real device, Xcode will random freeze, simulator is fine. It costs me lots of time to find it out. To someone suffering from this problem also. :) ENV: gambit 4.6.6 + cpp project MeroonV3-2012Jan20.tar.bz2 Xcode 4.3.3

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Re: [gambit-list] Downloading Gambit for Aneroid to Kindle Fire
by Steve Graham 11 Jul '12

11 Jul '12

Was able to backup app on phone, e-mail to Kindle and install. Steve Sent from Yahoo! Mail on Android

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Re: [gambit-list] Downloading Gambit for Aneroid to Kindle Fire
by Steve Graham 11 Jul '12

11 Jul '12

That should be Android :-) Sent from Yahoo! Mail on Android

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Downloading Gambit for Aneroid to Kindle Fire
by Steve Graham 11 Jul '12

11 Jul '12

I tried to do this and the screen at play.google.com says that it is installed, but the device itself shows no such app. Also tried unsuccessfully to load Clojure. Any ideas? Thanks. Steve Sent from Yahoo! Mail on Android

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How to use define-syntax and cond-expand in one program?
by Sven Hartrumpf 03 Jul '12

03 Jul '12

Hi all. I debugged the following compilation problem (v. 4.6.6): I am using 'gsc -:s ' because I need define-syntax, but then cond-expand is not working correctly. Any solutions? Sven

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