OCaml Weekly News

On behalf of the dune team, I'm pleased to announce the 1.10.0 release of dune. This release is packed with bug fixes, but it also introduces a few interesting features. I'll highlight one important feature that we've introduced and plan to improve in future versions:

Dune allows you to specify package metadata in the dune project file and generate an appropriate opam file. This is advantageous to writing opam files manually as dune will correctly fill in some boilerplate such as the build command:

Here's a snippet from dune's own project file as a demonstration:

(generate_opam_files true) ;; necessary to enbale the generation

(license MIT)
(maintainers "Jane Street Group, LLC <opensource@janestreet.com>")
(authors "Jane Street Group, LLC <opensource@janestreet.com>")
(source (github ocaml/dune))
(documentation "https://dune.readthedocs.io/")

(package
 (name dune)
 (depends
  (ocaml (>= 4.02))
  base-unix
  base-threads)
 (conflicts
  (jbuilder (<> "transition"))
  (odoc (< 1.3.0))
  (dune-release (< 1.3.0)))
 (synopsis "Fast, portable and opinionated build system")
 (description "<redacted>"))

Generating the opam file is done via $ dune build @check (the @install, and @all aliases will also work).

Later, we plan to have dune do some sanity checks on the depends field. In the more distant future, we might even skip the generation step altogether by having opam invoke dune to get the generated opam file directly.

As usual, the change log is replicated here for your convenience:

The release of OCaml version 4.08.0 is imminent. We have created a second release candidate that you can test.

The source code is available at these addresses:

https://github.com/ocaml/ocaml/archive/4.08.0+rc2.tar.gz
https://caml.inria.fr/pub/distrib/ocaml-4.08/4.08.0+rc2.tar.gz

The compiler can also be installed as an OPAM switch with one of the following commands.

opam switch create ocaml-variants.4.08.0+rc2 --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

or

opam switch create ocaml-variants.4.08.0+rc2+<VARIANT> --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

where you replace <VARIANT> with one of these:

• afl
• default_unsafe_string
• flambda
• fp
• fp+flambda

We want to know about all bugs. Please report them here: https://github.com/ocaml/ocaml/issues

Happy hacking,

– Damien Doligez for the OCaml team.

The only change from rc1 is the bug fix for #8705:
https://github.com/ocaml/ocaml/issues/8705
https://github.com/ocaml/ocaml/pull/8706

Editor's note: please follow the archive link for the full changelog from 4.07.1.

hdf5 0.1.5 is not available in OPAM. Since the version 0.1.2 it mostly got bug fixes.

https://en.wikipedia.org/wiki/Hierarchical_Data_Format

https://github.com/vbrankov/hdf5-ocaml

The Software Reliability and Security Lab at CEA LIST (Paris Saclay, France) is hiring a 2-year postdoctoral researcher who will improve E-ACSL, the runtime verification plug-in of Frama-C.

Frama-C is an opensource framework providing several analyzers for C code. The analyzed programs can be annotated by formal specifications written in the ACSL specification language. E-ACSL is one of the existing Frama-C analyzers. It converts ACSL annotations into C code in order to verify their validity at runtime, when the program is being executed.

The goal of this postdoctoral position is twofolds: on the one hand, the postdoctoral researcher shall propose new compilation schemes to support additional ACSL constructs; on the other hand (s)he shall define new compilation techniques (or adapt existing ones) in order to optimize the generated code for reducing the time overhead and the memory footprint of the generated program. The work will be guided by and evaluated on case studies providing by a few of our academic and industrial partners.

Knowledge in at least one of the following fields is required:

• functional programming (ideally OCaml)
• C programming
• compilation
• static analysis
• semantics of programming languages
• runtime verification
• formal specification

A full description of the position is available online:

http://julien.signoles.free.fr/positions/postdoc-eacsl.pdf

Feel free to contact me for additional details.

There is an amazing book called Category Theory for Programmers by Bartosz Milewski. At first it was focused on Haskell mostly, added Scala support after. But then someone stepped in to add the OCaml variant of this book. So writing this message as both recommendation for the book itself, and to be aware (and even better - to help) of the ongoing effort to make it OCaml-friendly.

See the current progress at https://github.com/ArulselvanMadhavan/ocaml-ctfp.

This is a patch/switch for basic printing of any value (excepting abstract and polymorphic elements) exactly as printed by the toplevel for a final result.

It's appropriate for debug purposes where custom crafted or ppx-deriving printers are overkill/inconvenient.

https://github.com/progman1/genprint