Here is the latest Caml Weekly News, for the week of November 01 to 08, 2011.
Archive: https://sympa-roc.inria.fr/wws/arc/caml-list/2011-11/msg00009.htmlGerd Stolpmann announced:
I've just released Plasma-0.5. Plasma consists now of three parts, namely PlasmaFS, PlasmaKV, and Plasma Map/Reduce: * PlasmaFS is a distributed replicating filesystem. Unlike other such filesystems, it is transactional and exhibits transactions to the user. Also, it implements almost all of what is known as POSIX semantics, and it is mountable. * PlasmaKV is a key/value database on top of PlasmaFS. It is designed for ultra-high read workloads, and offers interesting properties borrowed from PlasmaFS (e.g. replication and ACID transactions). * Plasma Map/reduce implements a variant of the popular computation scheme. The real major change in version 0.5 is the addition of PlasmaKV. Because PlasmaFS offers a richer API than is normally available from a filesystem, the implementation of this NoSQL db takes less than 2000 lines of code. Nevertheless, it has properties most other NoSQL db's cannot fully implement, like complete isolation between readers and writers (i.e. they do not lock each other out). A description of the concept can be found here: http://projects.camlcity.org/projects/dl/plasma-0.5/doc/html/Plasmakv_intro.html The extremely simple API: http://projects.camlcity.org/projects/dl/plasma-0.5/doc/html/Pkv_api.html The other major change in version 0.5 is the implementation of parallel commits in PlasmaFS. A test deployment showed that it is now possible to get around 500 commits/second. All pieces of software are bundled together in one download. The project page with further links is http://projects.camlcity.org/projects/plasma.html There is now also a homepage at http://plasma.camlcity.org THIS IS NOW A BETA RELEASE! I'm searching for testers. Whoever has access to a cluster please check Plasma out! Plasma is installable via GODI for Ocaml 3.12. For discussions on specifics of Plasma there is a separate mailing list: https://godirepo.camlcity.org/mailman/listinfo/plasma-list
Archive: https://sympa-roc.inria.fr/wws/arc/caml-list/2011-11/msg00010.htmlXavier Clerc announced:
This post announces the 1.0 release of the Argot project, whose goal is to provide an enhanced HTML generator for ocamldoc, released under the GPL v3. Home page: http://argot.x9c.fr Preview page (for search feature): http://argot.x9c.fr/distrib/argot-3.12-libref/index.html Forge page: https://forge.ocamlcore.org/projects/argot/ Main changes since 1.0-beta: - new '-search' command-line switch to generate search information (available on HTML pages through the magnifying glass icon) - search by exact name - search by name using regular expression - search by type using isomorphisms (experimental) - new '-definitions' command-line switch to load variables from file - correct handling of embedded tables - more predefined licenses for the '@license' tag - some refactoringFabrice Le Fessant then said:
By the way, Thomas is also working on a plugin for ocamldoc, with incremental search. An example of what it generates (for the stdlib and some of our internal libraries) is available here: http://www.ocamlpro.com/doc/stdlib/index_modules.html It is not yet released, but we plan to do it in the next months, with some other tools.Anil Madhavapeddy then added:
Thomas also prototyped a searchable version for the CUFP Mirage tutorial: e.g.: http://www.ocamlpro.com/mirage/xen/ ; but the search view does need some optimisation with a large number of modules, as in the standard library. The new version he's doing in HTML is far slicker and faster. Citrix have a really useful JSON output to ocamldoc in the XAPI tree that is very handy for anyone else who wants to do something like this: https://github.com/xen-org/xen-api/blob/master/ocaml/doc/odoc_json.mlrixed asked and Thomas Gazagnaire replied:
> Regarding search by type, I wonder if people actually use this for > useful reasons or if it's just out of curiosity or for the cool hack > factor -- and sure it's cool. I mean there's not enough semantics in > types to tell you what a function will do, and since we curry it is > not always clear in which order we will argument. To be clear, I implemented search by type in order to understand a bit more the book of Roberto Di Cosmo about type isomorphisms. Whether it can be a useful tool remains to be determined. The tool now exists, let's see if there is a usage for it. I do agree that there is often not enough semantics in OCaml types, but please notice that the order of arguments and whether the function is currified is not relevant. Indeed, doing type search up to isomorphisms allows to get rid of these details, all of the following queries will answer with "String.sub": - "int -> int -> string -> string" - "string -> (int * int) -> string" - "string * int *int -> string" while the actual signature is "string -> int -> int -> string".rixed asked and Fabrice Le Fessant replied:
> Last thing, unrelated: from the search box one can see you have many > modules extending the stdlib (the Ocp* modules). Why another stdlib > extension instead of, say, contributing to batteries ? First, we don't have so many of them, we only put there what we needed for our set of tools. Some of them are really close to the compiler, and we might submit them for inclusion in the official distribution, so we didn't want to add a dependency to Batteries or Core too early. The other reason is that we haven't tried Batteries or Core enough yet, we have constraints, and we must make sure that if we rely on the some library, the library fit these constraints. For example, I know that Core has not been tested on Windows, and I don't know for Batteries. Also, we want to separate between "lang" and "system", i.e. modules that can be implemented with the core language, and modules that have system dependencies. Finally, unlike other companies using OCaml, we want to provide support on the language itself, which means the compilers, other dev tools, and also basic libraries. So, at some point, we will have to contribute to either Core or Batteries, or both, but before that, we need to think more about our own idea of what a good standard library should be, to choose the best candidate from our point of view.Gerd Stolpmann also replied to the original announcement:
Excellent! I'll definitely use it. Another idea for a feature: more options how classes and modules are shown. For example, I once had the problem that I wanted an included module also to be included in-place in the documentation (rather than by reference/link). I modified the ocamldoc generator to get this effect, and the result is here: http://projects.camlcity.org/projects/dl/pxp-1.2.1/doc/manual/html/ref/Pxp_types.html The grey box contains actually the included definitions. This is much easier to understand for the casual reader. The feature is accompanied by a link rewriter, so the ocamldoc-generated links point to the including module rather the included module. A similar problem occurs for inherited class types. Of course, one wants to enable this on a case-by-case basis. I blogged about this some years ago: http://blog.camlcity.org/blog/pxp121.html The generator (very specific to this case): https://godirepo.camlcity.org/svn/lib-pxp/tags/pxp-1.2.1/tools/src/odoc/chtml.ml
Archive: https://sympa-roc.inria.fr/wws/arc/caml-list/2011-11/msg00038.htmlDaniel Bünzli asked and Gabriel Scherer replied:
> But having been recently forced out of emacs into a proprietary IDE to > be *able* to work on a project written in a > programmingLanguageWithAbsurdlyLongNamingConventions, one thing I > actually became very fond of is type aware autocompletion and the > ability to browse from a symbol in my code directly to the page where > its documented. The former may be complex to implement without > compiler support but I'm sure the latter is not. My elisp skills are > however too limited for me to implement that myself but I'd love to > have that in ocaml's emacs mode. There are various external projects/patches to do this kind of things: - Jun Furuse's [Ocamlspotter] is a patch to the compiler to enrich .annot files with where-defined information on symbols. It has some emacs integration code. - Peng Zang's Enhtop+ (an incremental update of Zeng Li's Enhtop enhanced toplevel) provides enviroment lookup capacities in the toplevel. He uses it to build [tuareg-plus], an emacs glue providing context-aware completion (I'm not sure how good it works though, never tried myself) [Ocamlspotter] http://jun.furuse.info/hacks/ocamlspotter [Enhtop+] http://www.cc.gatech.edu/~pengzang/enhtop+.html [Enhtop] http://www.pps.jussieu.fr/~li/software/index.html#enhtop [tuareg-plus] http://www.cc.gatech.edu/~pengzang/tuareg-plus.html Beware that all those projects tend to be built as patches to the ocaml distribution, which means difficult deployment (which means few users, which means few maintenance, which means bitrot). I'm not saying life is *easy* if you wish to use IDE tools for OCaml, only that it is possible. There are surely other alternatives I forgot about (please feel free to add something) and related projects that are interesting as well (eg. Jérémie Dimino 'utop' toplevel). You may also have a look at the various attempts at integrating OCaml with Java IDEs (Oca'IDE, Ocaml Development Tools, etc.). I'm various people are also developing new exciting tools. For example, Ocamlpro has announced that it could/would develop IDE tooling, for example; incidentally, they also work on internal passes dumping techniques that might make development and deployment of such tools easier in the future.
Archive: https://sympa-roc.inria.fr/wws/arc/caml-list/2011-11/msg00014.htmlJun Furuse asked and Nicolas Pouillard replied:
> I want to have pcre regexp literals in the same syntax as Perl i.e. > /hello\sworld\\n/. Currently what we do in OCaml is Pcre.regexp > "hello\\sworld\\\\n", where the backslash char must be escaped in a > OCaml string literal. This is lousy for scripting in OCaml. > > To have the same or similar syntax as Perl, the lexer must be really > modified. Currently I am using a modified CamlP4 where I can replace > its lexer function, but it is an adhoc way, and I am seeking any > healthier way without such a modification. As said earlier Camlp4's lexer is not extensible. One can change the meaning of the token stream using the token filters but this won't work in your case. The third option is to use quotations this is really the adapted feature for this task. Of course the syntax won't be as concise as /bla/... Regarding OCaml lexing you may be interested in camllexer  which is not intended to be extensible but is very small and selfcontained. If you really want to hack your own lexical syntax I suggest you to fork camllexer and change it for your purpose. : https://github.com/np/camllexerJérémie Dimino also suggested:
Have you look at camlp4 quotations ? Basically you can define a new quotation named "foo" and in you code you can write: <:foo<...>> The ... can be any string, except that it cannot contains >>. Also you may be interested in the Mikmatch syntax extension: http://martin.jambon.free.fr/micmatch.htmlJun Furuse then concluded:
Unfortunately the conclusion seems to be currently there is no way to change the lexer by pa_*.cmo modules. Then, I stick to my patched p4 approach for now. With it I can use $/regexp\n/i and $`find . -iname hoo` syntax, but for whom using the vanilla p4, they can still use <:m<regexp\n/i>> and <:qx<find . -iname hoo>> : https://bitbucket.org/camlspotter/orakuda/src/50d736f39428/test
Thanks to Alp Mestan, we now include in the Caml Weekly News the links to the recent posts from the ocamlcore planet blog at http://planet.ocamlcore.org/. ocamlnat: https://forge.ocamlcore.org/projects/ocamlnat/ Argot 1.0: http://caml.inria.fr/cgi-bin/hump.cgi?contrib=754 Plasma 0.5: http://caml.inria.fr/cgi-bin/hump.cgi?contrib=733 After NoSQL there will be NoServer: http://blog.camlcity.org/blog/plasma5.html Argot: 1.0: https://forge.ocamlcore.org/forum/forum.php?forum_id=813 OCaml, the ultimate refactoring tool: http://ocaml.janestcapital.com/?q=node/101 Disk space problem solved: https://forge.ocamlcore.org/forum/forum.php?forum_id=812
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