Here is the latest OCaml Weekly News, for the week of March 21 to 28, 2017.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00082.htmlIsaac Gouy announced:
It's been too many years since I mentioned that new and improved OCaml programs would be welcome contributions to the benchmarks game. Here are the existing programs: http://benchmarksgame.alioth.debian.org/u64q/measurements.php?lang=ocaml Here are instructions on how to contribute a program: http://benchmarksgame.alioth.debian.org/play.html
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00083.htmlContinuing this thread, Gabriel Scherer announced:
By the way, the unloading patch is now merged. (In trunk; it should not be part of the 4.05 release in preparation, but of 4.06 that should hopefully happen six months after that.)
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00084.htmlJulien Signoles announced:
The Software Reliability Lab at CEA LIST (Paris Saclay, France) is hiring a 18-month research engineer to improve the Frama-C runtime verification plug-in E-ACSL. A full description of the open position is available online: http://julien.signoles.free.fr/eacsl_engineer.pdf. Feel free to contact me for additional details
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00095.htmlChristoph Höger asked:
this is not entirely OCaml related, but somewhat more general. However, I hope that someone on that list can give me a pointer on how to proceed. Assume a simple OCaml program with two primitives that can cause side-effects: let counter = ref 0 let incr x = counter := !counter + x ; !counter let put n = counter := n; !counter put (5 + let f x = incr x in f 3) This example can be transformed into a pure program using a counter monad (using ppx_monadic syntax): do_; i <-- let f x = incr x in f 3 ; p <-- put (5 + i) return p For a suitable definition of bind and return, both programs behave equivalently. My question is: How can one automatically translate a program of the former kind to the latter? I assume, one needs a normal form that makes the order of evaluation explicit, but which normal form would that be? Is there a textbook algorithm for that kind of analysis? any pointers are appreciatedJeremy Yallop replied:
You might be interested in the following paper, which describes exactly such a translation: Lightweight Monadic Programming in ML Nikhil Swamy, Nataliya Guts, Daan Leijen, and Michael Hicks ICFP 2011 https://www.cs.umd.edu/~mwh/papers/swamy11monad.html
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00106.htmlDeep in this thread, Oleg said:
> The problem here is that echo (or printf) closes the pipe_in fifo, > hence sending EOF to the ocaml toplevel. You need to force the fifo to > somehow remain open. Eons ago, back in the last century, I wrote a simple tool for that task http://okmij.org/ftp/Communications.html#sh-agents to script almost anything from really anything. I used it to drive Mathematica (on a remote machine) from Emacs and database CLI tools. (I just realized it has been 20 years...)
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00110.htmlKenichi Asai asked:
What is the best way to do react.js programming as introduced in https://facebook.github.io/react/ in OCaml? I found the tutorial on the above page written very well, and I want to do the same thing in OCaml at the similar abstraction level as in JS. Any information is welcome. Thanks in advance.David Teller replied then Daniel Bünzli said:
> If I recall correctly, React.js is actually a JS port of the following > OCaml library: http://erratique.ch/software/react > > So that might be what you're looking for :) I don't think so AFAIK react.js has nothing to do with functional reactive programming.Zhi An Ng also replied:
Indeed, OCaml actually has the official support of ReactJS bindings provided by Facebook's Reason team and Bloomberg's BuckleScript compiler. According to React Conf 2017, it is used in production for already half a year and powered a quite large piece of components in FB's messenger.com Note ReasonML provides JSX syntax which is more familiar to ReactJS users, but you can use either Reason syntax or vanilla OCaml syntax.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00115.htmlFrancois Berenger announced:
A vantage point tree allows to do fast (but exact) nearest neighbor searches in a space of any dimension provided that you have a distance function (to measure the distance between any two points in that space). The code is here: https://github.com/UnixJunkie/vp-tree The interface looks like this: --- type 'a t val create: ('a -> 'a -> float) -> 'a list -> 'a t val nearest_neighbor: ('a -> 'a -> float) -> 'a -> 'a t -> float * 'a val to_list: 'a t -> 'a list val is_empty: 'a t -> bool --- The creation of a vp-tree can take some time. Queries are supposed to be fast. In my tests, queries can run several times faster than a brute force search once you have enough points indexed by your vpt. The implementation creates an optimal vp-tree; don't use it on large points set (> 10,000 points). You can install it via: $ opam install minivpt Contributions are very welcome to support large point sets, queries with a tolerance parameter (as in "only points within distance to query less than the tolerance"), and returning all points (instead of just one) if there are several points within the same distance to your query point. A usage example might be: --- let vpt = Vp_tree.create distance_fun points in let dist_to_query, nearest_point = \ Vp_tree.nearest_neighbor distance_fun query_point vpt in [...] --- My implementation follows the paper: "Data Structures and Algorithms for Nearest Neighbor Search in General Metric Spaces" by Peter N. Yianilos.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2017-03/msg00116.htmlHongbo Zhang announced:
Here is a sneak peek at some potential future features of the Ocaml compiler, discussed by their implementers in these Github Pull Requests. - Add compiler support for raw pointers https://github.com/ocaml/ocaml/pull/724 - Make process creation robust against duplicate descriptors https://github.com/ocaml/ocaml/pull/1105 - Fix PR6638: "unused open" warning was incorrectly suppressed by "open!" https://github.com/ocaml/ocaml/pull/1110 - Branchless computation of the integer absolute value https://github.com/ocaml/ocaml/pull/1113 - Support inherited field in object type expression https://github.com/ocaml/ocaml/pull/1118 - injective mapping between identifiers and printed names https://github.com/ocaml/ocaml/pull/1120 - Universal do..done https://github.com/ocaml/ocaml/pull/1122 - Remove global variables in hash.c https://github.com/ocaml/ocaml/pull/1123
Here are links from many OCaml blogs aggregated at OCaml Planet, http://ocaml.org/community/planet/. Polynomials over rings http://blog.shaynefletcher.org/2017/03/polynomials-over-rings.html
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