Here is the latest OCaml Weekly News, for the week of June 24 to July 01, 2014.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-06/msg00104.htmlGerd Stolpmann announced:
I just released findlib-1.5.1: - Including the "bytes" package that is either a compat package for ocaml < 4.02 or a fake package for ocaml >= 4.02. The package aims at helping to support the transition to the new "bytes" type for mutable strings. - Also installing findlib.cmxs if OCaml supports it. - Allowing to disable camlp4 (in prep for OCaml-4.02). - The "ppx" package property can be specified for constructing ppx-type preprocessors. Especially thanks to Peter Zotov who contributed several patches. More documentation and download: http://projects.camlcity.org/projects/findlib.html
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-06/msg00106.htmlLouis Mandel announced:
We are happy to announce the new release of ReactiveML: http://reactiveml.org with a new lesson in the interactive tutorial: http://reactiveml.org/tryrml ReactiveML could be easily installed using OPAM : opam install rml or directly from the source : http://reactiveml.org/distrib/rml-1.09.03-2014-06-21.tar.gz ReactiveML is a language similar to OCaml extended with a built-in notion of parallel composition. It is based on the reactive synchronous model, a cooperative concurrency model. The language is well suited to program applications with a lot of parallel processes which communicate and synchronize a lot such as video games or simulation problems. ReactiveML is compiled into plain OCaml code and thus can link or be linked to any OCaml code. -- Louis Mandel for the ReactiveML development team
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-06/msg00107.htmlThomas Braibant announced:
Last week, we had a very productive OCaml hacking session at IRILL. There were around 25 active participants, and the list of things that wre done is highly encouraging (see ). We look forward to organize another session like this one! The next OUPS meetup will be a regular meeting with talks. It will take place at *Mozilla Paris* on the 8th of July starting at 7 pm. For details about the location, please go  The tentative program is the following one: - Vincent Balat: Ocsigen: Web applications with Js_of_ocaml and Eliom - Roberto Di Cosmo: Leveraging Solver Preferences to Control your OCaml Package Manager - Jean-Christophe Filliâtre: Lessons from the implementation of a graph library, OCamlGraph - Simon Cruanes: Simple and efficient iterators - Felix S. Klock II (core dev. Rust): An Introduction to Rust for functional programmers (Invited talk). There will be drinks and some food afterwards, thanks to our sponsors for this event, LexiFi and Mozilla. Best, Thomas  https://github.com/braibant/oups/wiki  http://www.meetup.com/ocaml-paris/
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-06/msg00113.htmlDaniel Bünzli announced:
I'd like to announce uucp: Uucp is an OCaml library providing efficient access to a selection of character properties of the [Unicode character database]. Uucp is independent from any Unicode text data structure and has no dependencies. It is distributed under the BSD3 license. : http://www.unicode.org/reports/tr44/ Home page: http://erratique.ch/software/uucp Documentation: http://erratique.ch/software/uucp/doc/Uucp Github mirror: https://github.com/dbuenzli/uucp It should be available shortly in opam. A few comments about the library can be found at the end of this message. Part of this work was sponsored by OCaml Labs, many thanks for their support. Best, Daniel A few notes. * Having seen unwarranted sights of horror at the simple mention of Unicode by fellow peers I took the time to write an absolute minimal introduction to Unicode in the documentation: http://erratique.ch/software/uucp/doc/Uucp.html#uminimal At the end of this introduction end I also give a few biased tips on how Unicode can be handled in OCaml. * The data used to represent the properties is directly linked in your executables. In the future I will adapt the library to use OCaml 4.02 module aliases so that you only pay for the submodules you access. For now linking against the library on osx 64-bit, result in a 6.4 Mo executable and on linux 32-bit a 3.7 Mo executable. * If you are interested in Unicode caseless matching (equality) of strings or identifiers, the documentation of the Uucp.Case module has sample code on how to perform that using Uutf and Uunf. This code may eventually be gathered in a proper module in the future. http://erratique.ch/software/uucp/doc/Uucp.Case.html#caseexamples * Not all properties are exposed. Obsolete properties, deprecated properties and those that are specific to some unicode processing algorithm (bidi, segmentation, normalization, etc.) are left out. The reason for the latter is that these algorithm may need to devise their own, maybe more efficient, representations. For example the normalization properties are not included, as they are best stored, used and exposed by a module that performs normalization (e.g. Uunf). It is not excluded that I reverse this in the future and make Uunf dependent on Uucp as this could make maintenance easier (though Uunf sometimes uses optimized representations). Also if the data needs to be used by more than one module this may become less wasteful than each module including its own data. * Regarding the last point, the selection is subjective. If there's a property you feel is useful in the wide and missing please tell me (e.g. on github's issue tracker) with a good rationale and I will add it. The full list of omitted properties is available here: http://erratique.ch/software/uucp/doc/Uucp.html#distrib_omit
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-07/msg00005.htmlJohn Whitington:
I have prepared another little book about OCaml, a collection of sixteen little algorithms, methods, and diversions, together with Questions and Answers. Not quite as beginner-ish as "OCaml from the Very Beginning" but not, I hope, too intimidating at all. I've included the provisional table of contents below. Please drop me a note by email if you can spare a little time to review a draft, which should be ready soon. Free copies for people who provide substantive comments, like last time, of course. 1 Unravelling "Fold" 2 Being Lazy 3 Named Tuples with Records 4 Generalized Input/Output 5 Streams of bits 6 Compressing Data 7 Labelled and Optional Arguments 8 Formatted Printing 9 Searching For Things 10 Finding Permutations 11 Making Sets 12 Playing Games GENERATING PDF DOCUMENTS - AN EXTENDED EXAMPLE 13 Representing Documents 14 Writing Documents 15 Pretty Pictures 16 Adding Text I'll also be forwarding a copy to caml at inria.fr like last time, so if you're on that list, there is no need to contact me separately.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-07/msg00001.htmlGabriel Kerneis:
in CIL http://cil.sf.net, the module Pretty provides a Format-like interface with a few extensions compared to usual format strings. Implementation-wise, it uses string_of_format and re-implements most of the logic of the pre-4.02 Format module, with Obj.magic all over the place. I wondered if anyone has done something similar in their own project (extending Format in one way or another), and if the new GADT-based approach could provide a cleaner solution? One thing I quite like with the current code, despite its uglyness, is its concision. I am right in assuming that switching to GADTs would require a lot more boilerplate? Many thanks for any example you could provide.Tianyi Cui suggested and Gabriel Kerneis replied:
> I found https://github.com/janestreet/custom_printf quite > straightforward to understand and easy to use, if most of your types > already have sexp converters and to_string functions. Thanks. This is a nice hack (provided you are happy to use a pre-processor). However, if I understand correctly, it is limited to making %s and %a more convenient to use for existing Printf functions. I should probably have given more details in my initial request. CIL's Pretty.dprintf  constructs and returns a "document" (similar to PPrint.document, if you are more familiar with this library), to be later formated and rendered to a given width. I am not sure custom_printf provides that level of flexibility.  http://kerneis.github.io/cil/doc/html/cil/api/Pretty.html#VALdprintfJeremie Dimino also replied and Alain Frisch added:
> I had a quick look at [Pretty.dprintf] and I think you could use > [CamlinternalFormat.make_printf] to implement it with 4.02. @-sequences > are already recognized by the format parser in the compiler, but it > should be compatible with [Pretty]'s syntax, you just have to interpret > the constructors differently. It should actually make the code of > [Pretty.dprintf] much simpler. We had a very similar issue with some internal LexiFi library, also using @-markers, and returning some structured document. Jeremie's suggestion works very well. The code below won't compile, but it can give you an idea on how to proceed: let printf_k fmt_s (acc : (unit, t) CamlinternalFormat.acc) = let open CamlinternalFormat in let l = ref empty in let add x = l := conc !l x in let stack = ref  in let push x = stack := (x,!l) :: !stack; l := empty in let err () = Mlfi_isdatypes.ffailwith "Mlfi_pp.printf: invalid format string %S" fmt_s in let pop () = match !stack with | (x,old) :: st -> stack := st; let nl = !l in l := old; (x,nl) | _ -> err () in let rec k = function | Acc_string(p, s) -> k p; add (str s) | Acc_char(p, c) -> k p; add (str (String.make 1 c)) | Acc_delay(p, f) -> k p; add f | Acc_flush p -> k p | Acc_invalid_arg (_, msg) -> invalid_arg msg | Acc_formatting_lit (p, lit) -> k p; begin match string_of_formatting_lit lit with | "@[" -> push (`BoxLeft 2) | "@]" -> begin match pop () with | (`BoxLeft k,u) -> add (indent k u) | _ -> err () end | "@<" -> push `LineLeft | "@>" -> begin match pop () with | `LineLeft, u -> add (line u) | _ -> err () end | s -> add (str s) end | Acc_formatting_gen (p, _) -> k p | End_of_acc -> () in k acc; if !stack <>  then err (); !l let printf (Format (fmt, fmt_s) : ('a, unit, t, f) format4) : 'a = let open CamlinternalFormat in make_printf (fun () acc -> printf_k fmt_s acc) () End_of_acc fmt
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/. Notes on Naming: https://blogs.janestreet.com/notes-on-naming/?utm_source=rss&utm_medium=rss&utm_campaign=notes-on-naming Uucp 0.9.0: http://erratique.ch/software/uucp Parametric HOAS with first-class modules: http://syntaxexclamation.wordpress.com/2014/06/27/parametric-hoas-with-first-class-modules/ Full Time: Software Developer (Functional Programming) at Jane Street in New York, NY; London, UK; Hong Kong: http://jobs.github.com/positions/0a9333c4-71da-11e0-9ac7-692793c00b45 Escaping continuations: http://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/ Reading Lamport, again: https://blogs.janestreet.com/reading-lamport-again/?utm_source=rss&utm_medium=rss&utm_campaign=reading-lamport-again
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