Here is the latest OCaml Weekly News, for the week of January 26 to February 02, 2016.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-01/msg00091.htmlYaron Minsky announced:
Jane Street is looking to hire functional programmers for our offices in New York, London and Hong Kong. Jane Street has the largest team of OCaml developers in any industrial setting, and the world's largest OCaml codebase. We use OCaml for running our entire business, working on everything from statistical research to systems administration to automated trading systems. If you're interested in using OCaml to solve real-world problems, there's no better place. The atmosphere is informal and intellectual --- you'll get to work with an extremely talented group of developers and traders (a pretty geeky group in its own right), pushing the bounds of functional programming and learning about the business of trading. Compensation is more than competitive. We have a strong commitment to OCaml and to open-source software. We've continued to develop and release our own open source software, as well as support OCamlPro and OCaml Labs in building out infrastructure for the language. You don't need to know anything about finance, be a whiz at mathematical puzzles, or be a deep type theorist to qualify. We're looking for great software engineers, but beyond that, there's no narrow list of qualifications. Here are some resources you can use to learn more about Jane Street and what we do. - Our technical blog: http://blogs.janestreet.com - Our open source software: https://github.com/janestreet - A talk we just posted on why we use OCaml: https://blogs.janestreet.com/why-ocaml/ - Our main website: https://www.janestreet.com/programming You can apply here: http://janestreet.com/apply
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-01/msg00092.htmlpeio asked and Xavier Leroy replied:
> while doing some modular arithmetic I discovered that OCaml uses the > 'truncated division' convention for the `/` (quotient) operator. > Actually this convention may seem innocent but it greatly affects the > `mod` (remainder) operator: the sign of the result is the same as > dividend. > > After some research I realized that lots of people (D.Knuth!) > criticized this convention in favor of floored division (sign of > remainder same as divisor) or euclidean division (remainder always > positive). I know such a key component of the language isn't likely to > be changed but I would like to get some of the rationals behind this > decision. All contemporary microprocessors that implement division in hardware implement what you call truncated division. The other forms of division and modulus (there are at least two others) can be implemented on top of that. See this excellent summary: Daan Leijen, Division and Modulus for Computer Scientists , July 2003. http://research.microsoft.com/apps/pubs/default.aspx?id=151917 > At last another thing that (slightly) bugs me: why don't `ceil` and > `floor` have the type `float -> int`? Because the inherent definitions > of these functions talks about integers, not floats Yes, but with the type you propose they would overflow easily for large enough FP arguments. In FP computations involving ceil and floor, it is often possible to do the computation entirely in floating-point, avoiding catastrophic overflow cases. > Maybe even more subtle is that `truncate` > has type `float -> int`. In my opinion the type `float -> float` would > be more appropriate here because the truncation operation is about > approximating a real number with a decimal (we already got > `int_of_float` for rough converting). "truncate" and "int_of_float" are (currently) the same function.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-01/msg00105.htmlFrancois Berenger announced:
I am very pleased to announce the first official release of DAFT (v0.0.1). DAFT means DAFT Allows File Transfers. DAFT is meant at computational scientists who want to move files during distributed computational experiments from the command-line. In other words, one can see DAFT as a kind of distributed file-system except that it has a command line interface (instead of a file interface) and doesn't allow modification or deletion of a file once it was added to the system. DAFT features the following commands: - put (publish a file) - get (retrieve a previously published file) - bcast (publish a file (if needed) then make it available to all nodes) - scatter (a put load-balancing chunks over nodes) - ls (list the global state of the system) - exit (exit the client, you can come back later) - quit (shut down the whole system) DAFT should be available in opam soon, under the package name daft. DAFT should be a fine data companion to tools like PAR (https://savannah.nongnu.org/projects/par) or GNU parallel (https://www.gnu.org/software/parallel/). A tool related to DAFT is the excellent TakTuk (http://taktuk.gforge.inria.fr/). DAFT is meant to be used when you don't have access to a distributed file-system on your nodes and you don't want to hammer the nearest NFS server (if any). There is a video presentation of DAFT from the latest OCaml Users in Paris meeting (OUPS), the presentation starts around 6mn40s into the video: http://www.dailymotion.com/video/x3ihqqa_conf-42-meetup-oups_tech The slides of this presentation can be seen here: http://files.meetup.com/6604932/meetup_hiver_2015.zip DAFT is secure by default and a software for the post-Snowden era. All its messages are signed then encrypted. DAFT never require root rights to be compiled/installed/run. All you need is a regular UNIX user account and ssh access to the nodes you want to use during your computational experiment. DAFT uses the excellent open source libraries and tools: - obuild (to build) - batteries (extended stdlib) - cryptokit (compression, signatures, ciphers, modes, CSPRNG) - dolog (a minimalist lazy logger) - fileutils (many FS operations) - ZMQ (send atomic messages over the network) I consider this is a beta release: users might encounter bugs in case of intensive usage of the tool. I only had time to do medium-scale experiments with it (128 computers from grid5000 and only broadcasting files). I don't consider DAFT was used in production yet. If you want to help with the project: https://github.com/UnixJunkie/daft/issues
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-02/msg00000.htmlVincent Balat announced:
Here is a sneak peek at some potential future features of the Ocaml compiler, discussed by their implementers in these Github Pull Requests. Better type error location in presence of constraints https://github.com/ocaml/ocaml/pull/441 Remove ocamlbuild https://github.com/ocaml/ocaml/pull/443
Thanks to Alp Mestan, we now include in the OCaml Weekly News the links to the recent posts from the ocamlcore planet blog at http://planet.ocaml.org/. Psellos: OCaml on iOS Example Apps http://psellos.com/2016/01/2016.01.done-gone-blue.html OCamlCore Forge News: CCSS 1.6 released https://forge.ocamlcore.org/forum/forum.php?forum_id=927
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