OCaml Weekly News
Hello
Here is the latest OCaml Weekly News, for the week of June 04 to 11, 2019.
Table of Contents
Dune 1.10.0
Rudi Grinberg announced
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:
1.10.0 (04/06/2019)
- Restricted the set of variables available for expansion in the destination
filename of
install
stanza to simplify implementation and avoid dependency cycles. (#2073, @aalekseyev, @diml) - [menhir] call menhir from context root build_dir (#2067, @ejgallego, review by @diml, @rgrinberg)
- [coq] Add
coq.pp
stanza to help with pre-processing of grammar files (#2054, @ejgallego, review by @rgrinberg) - Add a new more generic form for the promote mode:
(promote (until-clean) (into <dir>))
(#2068, @diml) - Allow to promote only a subset of the targets via
(promote (only <pred>))
. For instance:(promote (only *.mli))
(#2068, @diml) - Improve the behavior when a strict subset of the targets of a rule is already in the source tree for projects using the dune language < 1.10 (#2068, fixes #2061, @diml)
- With lang dune >= 1.10, rules in standard mode are no longer allowed to produce targets that are present in the source tree. This has been a warning for long enough (#2068, @diml)
- Allow %{…} variables in pps flags (#2076, @mlasson review by @diml and @aalekseyev).
- Add a 'cookies' option to ppx_rewriter/deriver flags in library stanzas. This allow to specify cookie requests from variables expanded at each invocation of the preprocessor. (#2106, @mlasson @diml)
- Add more opam metadata and use it to generate
.opam
files. In particular, apackage
field has been added to specify package specific information. (#2017, #2091, @avsm, @jonludlam, @rgrinberg) - Clean up the special support for
findlib.dynload
. Before, Dune would simply match on the library name. Now, we only match on the findlib package name when the library doesn't come from Dune. Someone writing a library calledfindlib.dynload
with Dune would have to add(special_builtin_support findlib_dynload)
to trigger the special behavior. (#2115, @diml) - Install the
future_syntax
preprocessor asocaml-syntax-shims.exe
(#2125, @rgrinberg) - Hide full command on errors and warnings in development and show them in CI.
(detected using the
CI
environment variable). Commands for which the invocation might be omitted must output an error prefixed withFile ~. Add an ~--always-show-command-line
option to disable this behavior and always show the full command. (#2120, fixes #1733, @rgrinberg) - In
dune-workspace
files, add the ability to choose the host context and to create duplicates of the default context with different settings. (#2098, @TheLortex, review by @diml, @rgrinberg and @aalekseyev) - Add support for hg in
dune subst
(#2135, @diml) - Don't build documentation for implementations of virtual libraries (#2141, fixes #2138, @jonludlam)
- Fix generation of the
-pp
flag in .merlin (#2142, @rgrinberg) - Make
dune subst
add a(version ...)
field to thedune-project
file (#2148, @diml) - Add the
%{os_type}
variable, which is a short-hand for%{ocaml-config:os_type}
(#1764, @diml) - Allow
enabled_if
fields inlibrary
stanzas, restricted to the%{os_type}
,%{model}
,%{architecture}
,%{system}
variables (#1764, #2164 @diml, @rgrinberg) - Fix
chdir
on external and source paths. Dune will also fail gracefully if the external or source path does not exist (#2165, fixes #2158, @rgrinberg) - Support the
.cc
extension fro C++ sources (#2195, fixes #83, @rgrinberg) - Run
ocamlformat
relative to the context root. This improves the locations of errors. (#2196, fixes #1370, @rgrinberg) - Fix detection of
README
,LICENSE
,CHANGE
, andHISTORY
files. These would be undetected whenever the project was nested in another workspace. (#2194, @rgrinberg) - Fix generation of
.merlin
whenever there's more than one stanza with the same ppx preprocessing specification (#2209 ,fixes #2206, @rgrinberg) - Fix generation of
.merlin
in the presence of thecopy_files
stanza and preprocessing specifications of other stanazs. (#2211, fixes #2206, @rgrinberg) - Run
refmt
from the context's root directory. This improves error messages in case of syntax errors. (#2223, @rgrinberg) - In .merlin files, don't pass
-dump-ast
to thefuture_syntax
preprocessor. Merlin doesn't seem to like it when binary AST is generated by a-pp
preprocessor. (#2236, @aalekseyev) dune install
will verify that all files mentioned in all .install files exist before trying to install anything. This prevents partial installation of packages (#2230, @rgrinberg)
OCaml 4.08.0+rc2
Damien Doligez announced
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
Vladimir Brankov announced
hdf5 0.1.5 is not available in OPAM. Since the version 0.1.2 it mostly got bug fixes.
2-year Postdoc Position on Frama-C/E-ACSL
Julien Signoles announced
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.
Category theory for Programmers book - OCaml flavor
Anton Kochkov announced
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.
Genprint - general value printing
progman announced
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.
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.