Here is the latest Caml Weekly News, for the week of 09 to 16 November, 2004.
Archive: http://caml.inria.fr/archives/200411/msg00080.htmlSooHyoung Oh announced:
I'm pleased to announce "ocamllex tutorial". ---------------------------- Abstract This is a tutorial on how to use ocamllex which is distributed with Ocaml language. This document borrowed lots of part from flex manual. Please mail all comments and suggestions to <shoh at compiler dot kaist dot ac dot kr> This tutorial is work-in-progress. The latest version can be found at http://pllab.kaist.ac.kr/~shoh/ocaml/ocamllex-ocamlyacc/ocamllex-tutorial/index.html . The companion tutorial for ocamlyacc will be available at http://pllab.kaist.ac.kr/~shoh/ocaml/ocamllex-ocamlyacc/ocamlyacc-tutorial/index.html . You can find the source of this document in ocamllex-tutorial-src.tar.gz. For printing, pdf (A4 size) is presented, and there is html (tar.gz). You can download the source of examples used in this document from ocamllex-examples.tar.gz. Last updated: 2004-11-10
Archive: http://caml.inria.fr/archives/200411/msg00081.htmlSooHyoung Oh announced:
This is newer version of "ocamlyacc tutorial". ----------------------------- Abstract This is a tutorial on how to use ocamlyacc which is distributed with Ocaml language. Lots of part of this document are borrowed from the bison manual. All license term in this document is NOT related with ocamlyacc; it is ONLY for this document. Please mail all comments and suggestions to <shoh at compiler dot kaist dot ac dot kr> This tutorial is work-in-progress. The latest version can be found at http://pllab.kaist.ac.kr/~shoh/ocaml/ocamllex-ocamlyacc/ocamlyacc-tutorial/index.html . The companion tutorial for ocamllex is available at http://pllab.kaist.ac.kr/~shoh/ocaml/ocamllex-ocamlyacc/ocamllex-tutorial/index.html . You can find the source of this document in ocamlyacc-tutorial-src.tar.gz. For who wants the other form, pdf (A4 size) for printing and html (tar.gz) are presented. The source of the examples used in this document can be found ocamlyacc-examples.tar.gz. Last updated: 2004-11-10
Archive: http://caml.inria.fr/archives/200411/msg00085.htmlOwen Gunden announced:
O'Caml ANSIColor is a library for creating colorful text and other effects in ANSI-compatible terminals. The code is staggeringly simple, and the interface and implementation are both very roughly based on Term::ANSIColor (a CPAN module). Homepage: http://projects.phauna.org/ansicolor/ API: http://projects.phauna.org/ansicolor/doc/ Tarball: http://projects.phauna.org/ansicolor/release/ansicolor-0.5.tar.gz GODI package: godi-ansicolor* *: currently there is only a godi package for the 3.08 GODI distribution. If there is demand and someone is willing to test with 3.07 I will gladly put the package into the 3.07 distribution as well. That is all.
Archive: http://caml.inria.fr/archives/200411/msg00100.htmlAlex Baretta asked:
We are writing a library implementing binary client-server protocol based on the Marshal module. In order to guarantee some degree of type-safety, during the handshaking phase of the communication we need the client to send the server the MD5 checksums of all relevant modules. The server process must verify that it has all the mentioned modules and that the checksums are consistent with its own. We are currently generating MD5 checksums from our source files with the md5sum command. These checksums are then assembled into a new source file which is compiled and linked into the both executables. This process works coherently for byte and native code, but it has at least one important drawback: all relevant modules must be available as source files for the md5 source file generation to work. Besides, this makes the compilation process exceedingly complex. We have found that the md5sum can be fetced directly from the executable file associated to the process. This technique is documented nowhere, as far as I can see, but the source code of Symtable.init_toplevel is very informative as to how to do this for bytecode executables. What I would like to know is how to implement this technique for native code executables. Essentially, how am I supposed to parse the binary executable to extract the symtable information. Also, how am I supposed to figure out at runtime whether I must use the bytecode method or the native code method? Equivalently, how do I know at runtime if the process is running a bytecode executable or a native one? Thank you very much.Xavier Leroy answered:
> We have found that the md5sum can be fetced directly from the executable > file associated to the process. This technique is documented nowhere, as > far as I can see, but the source code of Symtable.init_toplevel is very > informative as to how to do this for bytecode executables. What I would > like to know is how to implement this technique for native code > executables. Essentially, how am I supposed to parse the binary > executable to extract the symtable information. You cannot, because the checksums you mention (the digests of the interfaces of the modules) are not included in ocamlopt-generated executables. They are included only in ocamlc-generated executables (in the CRCS section) for use with Dynlink and the toplevel. At any rate, I think you're on the wrong tracks: the checksums you'll find in the CRCS section of bytecode executable are those of module interfaces, not of module implementations. To establish type agreement between two processes communicating via output_value/input_value, you really want the latter, not the former. (Think of an abstract type implemented differently in the two processes. For more details, see e.g. the ICFP'03 paper by Leifer, Peskine, Sewell and Wansbrough.) So, you're looking for convenient ways to collect checksums for module implementations. An insight that might simplify your build process is that while these checksums must be computed at compile-time (e.g. by running md5sum on the source .ml files), they can be collected together at run-time. For instance, you could preprocess the .ml sources of interest so as to insert at the beginning let _ = Registry.record_module "Modulename" "checksum" where "Modulename" is the module name and "checksum" the outcome of md5sum on the source file. The Registry.record_module function just accumulates its arguments in a hashtable or association list, which can then be consulted during the agreement phase of your protocol. There are probably many other ways to do it. But I think your initial idea (compute checksums of source files at compile-time) is the correct one, it's just a question of implementing it in a way that doesn't complicate your build process too much.
Archive: http://caml.inria.fr/archives/200411/msg00125.htmlVincenzo Ciancia announced:
Hi all, I am trying to write a complete, up-to-date, efficient and correctly multithreaded binding to the fuse api for ocaml. Fuse is a linux kernel module allowing filesystems to be implemented in user space, see http://www.sourceforge.net/projects/fuse By now, OCamlFuse is complete and up-to-date, but multithreading has troubles. Anyway, I declare the single-threaded version to be in alpha-testing (i.e. internal, developers testing). Since I consider the developers of any free-software projects to be everybody willing to join, I announce it here, in the hope that someone will want to have a look at my efforts and to test it, write some example filesystem in ocaml, comment on the interface and possible improvements in implementation, or even better to help with multithreading, which "should" work but crashes under heavy load for mysterious reasons. Help or advices for packaging are also wanted, since I don't know too much about GODI or ocamlfindlib and have not so much free time to work on this project. I will answer to any question on the ocamlfuse-devel mailing list, please read the README to know fundamental issues. The source lives in the cvs; you can find everything needed, including the mailing list, on the sourceforge project page: http://www.sourceforge.net/projects/ocamlfuse I did everything in a hurry, and on a by-need basis, I am not an expert user of the ocaml C interface, so if you have suggestions, don't hesitate to tell me :)Matt Gushee asked and Vincenzo Ciancia answered:
> I'm interested in this. First of all, what was wrong with the > existing mlfuse library? (I'm not saying there's nothing wrong with > it, I just don't know--hadn't tried it yet). It's not up-to-date (fuse is going towards its 2.1 release, while the existing mlfuse is for fuse 0.9), and it was not designed with multithreading in mind. If the latter was not true, I would not have rewritten it, however by now I must record a failure, since I did this all to get multithreading working and had no success :/ I am going to try to spot the problem this weekend - it's related to a previous recent post of mine on this list. Apart from this, a question to the list: to implement the read and write operations I am constrained to string copying. Is there a way to share a string with C in ocaml or should I roll my own "cstring" type and use that, copying from/to strings using memcpy when necessary?
Archive: http://caml.inria.fr/archives/200411/msg00128.htmlJulien Signoles announced:
I'm please to announce that a new (major) release (version 1.09.0) of the calendar library is available at: http://www.lri.fr/~signoles/prog.en.html calendar is an ocaml library managing dates and times. The latest changes follow. In particular, this release adds features of Richard Jones' GregorianDate. CHANGES: * add Date.to_business and Date.from_business (Richard Jone's suggestion) * add the optional parameter ?month to Date.days_in_year (Richard Jones' suggestion) * add Date.nth_weekday_of_month (Richard Jones' suggestion) * Date: add some Christian dates (Richard Jones' suggestion) * add Date.Period.ymd and Calendar.Period.ymds * Printer: add the format string %i corresponding to the ISO-8601 notation * Printer: ISO-8601 notation is now the default format * add [equal] in all the modules * Calendar.Period: bug fixed with negative period * bug fixed in Calendar.to/from_unixfloat and Date.to/from_unixfloat * bug fixed in weeks_in_yearOwen Gunden added:
And the godi package (godi-calendar) has been updated to version 1.09.0. Give it a whirl!
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