[cwn] Attn: Development Editor, Latest OCaml Weekly News

[Alan Schmitt]

Hello

Here is the latest OCaml Weekly News, for the week of January 14 to 21,
2020.

Table of Contents
─────────────────

How does the compiler check for exhaustive pattern matching?
resto 0.2 released
opam 2.0.6 release
soupault: a static website generator based on HTML rewriting
Spin: Project scaffolding tool and set of templates for Reason and OCaml
Old CWN


How does the compiler check for exhaustive pattern matching?
════════════════════════════════════════════════════════════

  Archive:
  <https://discuss.ocaml.org/t/how-does-the-compiler-check-for-exhaustive-pattern-matching/5013/1>


Dylan Irlbeck asked
───────────────────

  Hi all. I'm relatively new to OCaml, and I was curious on how the
  compiler is able to give a warning when a case list is non-exhaustive
  - both from a high-level and, if possible, the implementation of this
  check. I have some ideas about how one could do this, but none of my
  ideas seem like they'd be nearly as efficient as the OCaml compiler
  is.


gasche replied
──────────────

  The canonical reference for exhaustivity-checking in OCaml is the
  scientific publication

        [Warnings for pattern matching] Luc Maranget 2007

  The general idea is to consider all the patterns of a given
  pattern-matching at once, generalize this structure to a "matrix" of
  patterns (matching on several values in parallel), and devise an
  algorithm to "explore" these pattern matrices in such a way that you
  eventually tell if a given pattern-matrix is exhaustive, or can
  propose a counter-example.

  (I guess we should write a high-level/accessible blog post about
  this.)


[Warnings for pattern matching]
<http://moscova.inria.fr/~maranget/papers/warn/index.html>


resto 0.2 released
══════════════════

  Archive: <https://discuss.ocaml.org/t/ann-resto-0-2-released/5028/1>


Raphaël Proust announced
────────────────────────

  On behalf on Nomadic Labs, I'm happy to announce the release of
  version 0.2 of `resto', a library to create type-safe HTTP/JSON
  services.

  The library is available through opam (`opam install resto'),
  distributed under LGPL, and hosted on
  <https://gitlab.com/nomadic-labs/resto>.

  `resto' was previously released as `ocplib-resto' maintained by
  OCamlPro. The project is now maintained by Nomadic Labs.

  Along with many bugfixes and a few added features, the main change of
  this release is that the library is split into multiple packages with
  fine-grained dependencies.


opam 2.0.6 release
══════════════════

  Archive: <https://discuss.ocaml.org/t/ann-opam-2-0-6-release/5038/1>


R. Boujbel announced
────────────────────

  We are pleased to announce the minor release of [opam 2.0.6].

  This new version contains mainly build update & fixes. You can find
  more information in this [blog post].

  _opam is a source-based package manager for OCaml. It supports
  multiple simultaneous compiler installations, flexible package
  constraints, and a Git-friendly development workflow._


[opam 2.0.6] <https://github.com/ocaml/opam/releases/tag/2.0.6>

[blog post] <https://opam.ocaml.org/blog/opam-2-0-6>


soupault: a static website generator based on HTML rewriting
════════════════════════════════════════════════════════════

  Archive:
  <https://discuss.ocaml.org/t/ann-soupault-a-static-website-generator-based-on-html-rewriting/4126/11>


Daniil Baturin announced
────────────────────────

  soupault 1.8.0 is [released] along with Lua-ML 0.9.1.

  Lua-ML now raises `Failure' when Lua code execution fails. There's
  much room for improvement in that area, for now I've just done
  something that is better than just displaying errors on stderr but
  otherwise allowing syntax and runtime errors pass silently.

  If you have any ideas how perfect interpreter error reporting _should_
  work, please share!

  As of improvements in soupault itself, there's now:
  • A way for plugins to specify their minimum supported soupault
    version like `Plugin.require_version("1.8.0")'
  • `TARGET_DIR' environment variable and `target_dir' Lua global that
    contains the directory where the rendered page will be written, to
    make it easier for plugins/scripts to place processed assets
    together with pages.
  • "Build profiles": if you add `profile = "production"' or similar to
    widget config, that widget will be ignored unless you run `soupault
    --profile production'.
  • A bunch of new utility functions for plugins.


[released] <https://soupault.neocities.org/blog/soupault-1.8.0-release/>


Spin: Project scaffolding tool and set of templates for Reason and OCaml
════════════════════════════════════════════════════════════════════════

  Archive:
  <https://discuss.ocaml.org/t/spin-project-scaffolding-tool-and-set-of-templates-for-reason-and-ocaml/5047/1>


Mohamed Elsharnouby announced
─────────────────────────────

  <https://github.com/tmattio/spin>


Old CWN
═══════

  If you happen to miss a CWN, you can [send me a message] and I'll mail
  it to you, or go take a look at [the archive] or the [RSS feed of the
  archives].

  If you also wish to receive it every week by mail, you may subscribe
  [online].

  [Alan Schmitt]


[send me a message] <mailto:alan.schmitt at polytechnique.org>

[the archive] <http://alan.petitepomme.net/cwn/>

[RSS feed of the archives] <http://alan.petitepomme.net/cwn/cwn.rss>

[online] <http://lists.idyll.org/listinfo/caml-news-weekly/>

[Alan Schmitt] <http://alan.petitepomme.net/>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.idyll.org/pipermail/caml-news-weekly/attachments/20200121/3843f0ed/attachment.html>