HelloHere is the latest OCaml Weekly News, for the week of September 17 to
24, 2019.
Table of Contents ───────────────── Interesting OCaml Articles How does one print any type? OCamlPro cheat-sheets updates OCaml 4.09.0 released OCaml Training 5-6 and 7-8 November 2019 at OCamlPro Arch Linux installer written in OCaml Online programming playground A look back on OCaml 4.*Multicore prerequisite patches appearing in released OCaml compilers now
Old CWN Interesting OCaml Articles ══════════════════════════ Archive: <https://discuss.ocaml.org/t/interesting-ocaml-articles/1867/54> Ryan Slade announced ──────────────────── I thought this might be of interest since AFAIK the backend is implemented in OCaml: <https://darklang.com/> How does one print any type? ════════════════════════════ Archive: <https://discuss.ocaml.org/t/how-does-one-print-any-type/4362/7> Continuing this thread, rixed said ──────────────────────────────────As an additional piece of information, Batteries has to be mentioned. Batteries is a superset of the standard library which, amongst other things, offers composable printers for every types, so that it is often not necessary to devise custom printers for your own types.
For instance, if you had this type: ┌──── │ type t = (string, (float * int) list) Hashtbl.t └──── then a printer for this would be: ┌──── │ let print output_chan value =│ Hashtbl.print String.print (List.print (Tuple2 Float.print Int.print)) output_chan value
└──── Basically the kind of code that the ppx_deriving extension wouldgenerate, with the advantage that you can more easily substitute part
of it with some custom printers of your own. Marek Kubica also said ──────────────────────If you just want composable printers, there is the `Fmt' library by
@dbuenzli. OCamlPro cheat-sheets updates ═════════════════════════════ Archive: <https://sympa.inria.fr/sympa/arc/caml-list/2019-09/msg00014.html> Thomas Blanc announced ────────────────────── It is our pleasure to announce the release of our up-to-datecheat-sheets for the OCaml language and standard library. Our original cheat-sheets were published in 2011, and as you know there has been
quite a few changes in the language, library and ecosystem overall. See <http://www.ocamlpro.com/2019/09/13/updated-cheat-sheets-ocaml-language-and-ocaml-standard-library/> for details. Links: • OCaml language (pdf, 1 page): <http://www.ocamlpro.com/wp-content/uploads/2019/09/ocaml-lang.pdf> • OCaml stdlib (pdf, 2 pages): <http://www.ocamlpro.com/wp-content/uploads/2019/09/ocaml-stdlib.pdf> • Sources: <https://github.com/OCamlPro/ocaml-cheat-sheets>Comments and contributions on Github are welcome. Special thanks to Hannes Mehnert for his lightning fast bug-reporting and Fourchaux for
his keen spelling eye. As you can see, our Github repository contains not-yet-updated cheat-sheets. Stay tuned for coming updates! Obviously, our opamcheat-sheet is already in writing by the greatest opam experts you can
find. We also wish to make sheets for Lwt, Core, Dune, ppx - any suggestions are welcome. Happy hacking! Thomas Blanc OCamlPRO SASPS: if you're curious about what we've been doing lately, check out
our blogpotst: <http://www.ocamlpro.com/2019/08/30/ocamlpros-compiler-team-work-update/> <http://www.ocamlpro.com/2019/07/11/opam-2-0-5-release/> <http://www.ocamlpro.com/2019/07/09/alt-ergo-participation-to-the-smt-comp-2019/> OCaml 4.09.0 released ═════════════════════Archive: <https://discuss.ocaml.org/t/ocaml-4-09-0-released/4384/1>
octachron announced ───────────────────The OCaml team have the pleasure of celebrating the birth of James Waddell Alexander II by announcing the release of OCaml version 4.09.0
. Some of the highlights of this new 4.09 release are:• New optimisations, in particular for affine functions in matches,
for instance ┌──── │ type t = A | B | C │ let affine = function │ | A -> 4 │ | B -> 3 │ | C -> 2 └────• The `graphics' library was moved out of the compiler distribution.
• The `vmthread' library was removed. • Support for compiler plugins was removed. • Many bug fixes. The full list of change can be found in the changelog below.It is available as a set of OPAM switches, and as a source download
here: <https://caml.inria.fr/pub/distrib/ocaml-4.09/> Happy hacking. Changes ╌╌╌╌╌╌╌ This is the [changelog].[changelog] <http://caml.inria.fr/pub/distrib/ocaml-4.09/notes/Changes>
◊ Runtime system:• (*breaking change*) [#1725], [#2279]: Deprecate Obj.set_tag and
Obj.truncate (Stephen Dolan, review by Gabriel Scherer, Damien Doligez and Xavier Leroy) • (*breaking change*) [#2240]: Constify "identifier" in struct custom_operations (Cedric Cellier, review by Xavier Leroy)• (*breaking change*) [#2293]: Constify "caml_named_value" (Stephen
Dolan, review by Xavier Leroy) • [#8787], [#8788]: avoid integer overflow incaml_output_value_to_bytes (Jeremy Yallop, report by Marcello Seri)
• [#2075], [#7729]: rename _T macro used to support Unicode in the (Windows) runtime in order to avoid compiler warning (Nicolás Ojeda
Bär, review by Gabriel Scherer and David Allsopp)• [#2250]: Remove extra integer sign-extension in compare functions
(Stefan Muenzel, review by Xavier Leroy)• [#8607]: Remove obsolete macros for pre-2002 MSVC support (Stephen
Dolan, review by Nicolás Ojeda Bär and David Allsopp) • [#8656]: Fix a bug in [caml_modify_generational_global_root] (Jacques-Henri Jourdan, review by Gabriel Scherer) [#1725] <https://github.com/ocaml/ocaml/issues/1725> [#2279] <https://github.com/ocaml/ocaml/issues/2279> [#2240] <https://github.com/ocaml/ocaml/issues/2240> [#2293] <https://github.com/ocaml/ocaml/issues/2293> [#8787] <https://github.com/ocaml/ocaml/issues/8787> [#8788] <https://github.com/ocaml/ocaml/issues/8788> [#2075] <https://github.com/ocaml/ocaml/issues/2075> [#7729] <https://github.com/ocaml/ocaml/issues/7729> [#2250] <https://github.com/ocaml/ocaml/issues/2250> [#8607] <https://github.com/ocaml/ocaml/issues/8607> [#8656] <https://github.com/ocaml/ocaml/issues/8656> ◊ Standard library:• [#2262]: take precision (.<n>) and flags ('+' and ' ') into account
in printf %F (Pierre Roux, review by Gabriel Scherer)• [#6148], [#8596]: optimize some buffer operations (Damien Doligez, reports by John Whitington and Alain Frisch, review by Jeremy Yallop
and Gabriel Scherer) [#2262] <https://github.com/ocaml/ocaml/issues/2262> [#6148] <https://github.com/ocaml/ocaml/issues/6148> [#8596] <https://github.com/ocaml/ocaml/issues/8596> ◊ Other libraries: • (*breaking change*) [#2318]: Delete the graphics library. This library is now available as a separate "graphics" package inopam. Its new home is: <https://github.com/ocaml/graphics> (Jérémie Dimino, review by Nicolas Ojeda Bar, Xavier Leroy and Sébastien
Hinderer)• (*breaking change*) [#2289]: Delete the vmthreads library. This
library was deprecated in 4.08.0. (Jérémie Dimino)• [#2112]: Fix Thread.yield unfairness with busy threads yielding to each other. (Andrew Hunter, review by Jacques-Henri Jourdan, Spiros
Eliopoulos, Stephen Weeks, & Mark Shinwell)• [#7903], [#2306]: Make Thread.delay interruptible by signals again (Xavier Leroy, review by Jacques-Henri Jourdan and Edwin Török)
• [#2248]: Unix alloc_sockaddr: Fix read of uninitialized memory for an unbound Unix socket. Add support for receiving abstract (Linux) socket paths. (Tim Cuthbertson, review by Sébastien Hinderer and
Jérémie Dimino) [#2318] <https://github.com/ocaml/ocaml/issues/2318> [#2289] <https://github.com/ocaml/ocaml/issues/2289> [#2112] <https://github.com/ocaml/ocaml/issues/2112> [#7903] <https://github.com/ocaml/ocaml/issues/7903> [#2306] <https://github.com/ocaml/ocaml/issues/2306> [#2248] <https://github.com/ocaml/ocaml/issues/2248> ◊ Compiler user-interface and warnings:• (*breaking change*) [#2276]: Remove support for compiler plugins and hooks (also adds [Dynlink.unsafe_get_global_value]) (Mark Shinwell, Xavier Clerc, review by Nicolás Ojeda Bär, Florian Angeletti, David
Allsopp and Xavier Leroy)• [#2301]: Hint on type error on int literal (Jules Aguillon, review by Nicolás Ojeda Bär , Florian Angeletti, Gabriel Scherer and Armaël
Guéneau)• (*breaking change*) [#2314]: Remove support for gprof profiling.
(Mark Shinwell, review by Xavier Clerc and Stephen Dolan)• [#2190]: fix pretty printing (using Pprintast) of "lazy …" patterns and "fun (type t) -> …" expressions. (Nicolás Ojeda Bär, review by
Gabriel Scherer)• [#2277]: Use newtype names as type variable names The inferred type of (fun (type t) (x : t) -> x) is now printed as ('t -> 't) rather
than ('a -> 'a). (Matthew Ryan)
• [#2309]: New options -with-runtime and -without-runtime in
ocamlopt/ocamlc that control the inclusion of the runtime
system in
the generated program. (Lucas Pluvinage, review by Daniel
Bünzli,
Damien Doligez, David Allsopp and Florian Angeletti)• [#3819], [#8546] more explanations and tests for illegal permutation
(Florian Angeletti, review by Gabriel Scherer) • [#8537]: fix the -runtime-variant option for bytecode (Damien Doligez, review by David Allsopp)• [#8541]: Correctly print multi-lines locations (Louis Roché, review
by Gabriel Scherer) • [#8579]: Better error message for private constructors of anextensible variant type (Guillaume Bury, review by many fine eyes)
[#2276] <https://github.com/ocaml/ocaml/issues/2276> [#2301] <https://github.com/ocaml/ocaml/issues/2301> [#2314] <https://github.com/ocaml/ocaml/issues/2314> [#2190] <https://github.com/ocaml/ocaml/issues/2190> [#2277] <https://github.com/ocaml/ocaml/issues/2277> [#2309] <https://github.com/ocaml/ocaml/issues/2309> [#3819] <https://github.com/ocaml/ocaml/issues/3819> [#8546] <https://github.com/ocaml/ocaml/issues/8546> [#8537] <https://github.com/ocaml/ocaml/issues/8537> [#8541] <https://github.com/ocaml/ocaml/issues/8541> [#8579] <https://github.com/ocaml/ocaml/issues/8579> ◊ Code generation and optimizations:• [#2278]: Remove native code generation support for 32-bit Intel macOS, iOS and other Darwin targets. (Mark Shinwell, review by
Nicolas Ojeda Bar and Xavier Leroy)• [#8547]: Optimize matches that are an affine function of the input.
(Stefan Muenzel, review by Alain Frisch, Gabriel Scherer)• [#1904], [#7931]: Add FreeBSD/aarch64 support (Greg V, review by Sébastien Hinderer, Stephen Dolan, Damien Doligez and Xavier Leroy)
• [#8507]: Shorten symbol names of anonymous functions in Flambda mode (the directory portions are now hidden) (Mark Shinwell, review by
Nicolás Ojeda Bär)• [#8681], [#8699], [#8712]: Fix code generation with nested let rec of functions. (Stephen Dolan, Leo White, Gabriel Scherer and Pierre Chambart, review by Gabriel Scherer, reports by Alexey Solovyev and
Jonathan French) [#2278] <https://github.com/ocaml/ocaml/issues/2278> [#8547] <https://github.com/ocaml/ocaml/issues/8547> [#1904] <https://github.com/ocaml/ocaml/issues/1904> [#7931] <https://github.com/ocaml/ocaml/issues/7931> [#8507] <https://github.com/ocaml/ocaml/issues/8507> [#8681] <https://github.com/ocaml/ocaml/issues/8681> [#8699] <https://github.com/ocaml/ocaml/issues/8699> [#8712] <https://github.com/ocaml/ocaml/issues/8712> ◊ Manual and documentation: • [#7584], [#8538]: Document .cmt* files in the "overview" of ocaml{c,opt} (Oxana Kostikova, rewiew by Florian Angeletti)• [#8757]: Rename Pervasives to Stdlib in core library documentation.
(Ian Zimmerman, review by David Allsopp)• [#8515]: manual, precise constraints on reexported types (Florian
Angeletti, review by Gabriel Scherer) [#7584] <https://github.com/ocaml/ocaml/issues/7584> [#8538] <https://github.com/ocaml/ocaml/issues/8538> [#8757] <https://github.com/ocaml/ocaml/issues/8757> [#8515] <https://github.com/ocaml/ocaml/issues/8515> ◊ Tools:• [#2221]: ocamldep will now correctly allow a .ml file in an include directory that appears first in the search order to shadow a .mli appearing in a later include directory. (Nicolás Ojeda Bär, review
by Florian Angeletti) [#2221] <https://github.com/ocaml/ocaml/issues/2221> ◊ Internal/compiler-libs changes: • [#1579]: Add a separate types for clambda primitives (Pierre Chambart, review by Vincent Laviron and Mark Shinwell)• [#1965]: remove loop constructors in Cmm and Mach (Vincent Laviron)
• [#1973]: fix compilation of catches with multiple handlers (Vincent
Laviron)• [#2228], [#8545]: refactoring the handling of .cmi files by moving the logic from Env to a new module Persistent_env (Gabriel Scherer,
review by Jérémie Dimino and Thomas Refis)• [#2229]: Env: remove prefix_idents cache (Thomas Refis, review by
Frédéric Bour and Gabriel Scherer)• [#2237], [#8582]: Reorder linearisation of Trywith to avoid a call instruction (Vincent Laviron and Greta Yorsh, additional review by Mark Shinwell; fix in [#8582] by Mark Shinwell, Xavier Leroy and
Anil Madhavapeddy)• [#2265]: Add bytecomp/opcodes.mli (Mark Shinwell, review by Nicolas
Ojeda Bar)• [#2268]: Improve packing mechanism used for building compilerlibs modules into the Dynlink libraries (Mark Shinwell, Stephen Dolan,
review by David Allsopp)• [#2280]: Don't make more Clambda constants after starting Cmmgen
(Mark Shinwell, review by Vincent Laviron)• [#2281]: Move some middle-end files around (Mark Shinwell, review by
Pierre Chambart and Vincent Laviron)• [#2283]: Add [is_prefix] and [find_and_chop_longest_common_prefix] to [Misc.Stdlib.List] (Mark Shinwell, review by Alain Frisch and
Stephen Dolan) • [#2284]: Add various utility functions to [Misc] and removefunctions from [Misc.Stdlib.Option] that are now in [Stdlib.Option]
(Mark Shinwell, review by Thomas Refis)• [#2286]: Functorise [Consistbl] (Mark Shinwell, review by Gabriel
Radanne)• [#2291]: Add [Compute_ranges] pass (Mark Shinwell, review by Vincent
Laviron)• [#2292]: Add [Proc.frame_required] and [Proc.prologue_required].
Move tail recursion label creation to [Linearize]. Correctlyposition [Lprologue] relative to [Iname_for_debugger] operations.
(Mark Shinwell, review by Vincent Laviron)• [#2308]: More debugging information on [Cmm] terms (Mark Shinwell,
review by Stephen Dolan)• [#7878], [#8542]: Replaced TypedtreeIter with tast_iterator (Isaac
"Izzy" Avram, review by Gabriel Scherer and Nicolás Ojeda Bär) • [#8598]: Replace "not is_nonexpansive" by "maybe_expansive".(Thomas Refis, review by David Allsopp, Florian Angeletti, Gabriel
Radanne, Gabriel Scherer and Xavier Leroy) [#1579] <https://github.com/ocaml/ocaml/issues/1579> [#1965] <https://github.com/ocaml/ocaml/issues/1965> [#1973] <https://github.com/ocaml/ocaml/issues/1973> [#2228] <https://github.com/ocaml/ocaml/issues/2228> [#8545] <https://github.com/ocaml/ocaml/issues/8545> [#2229] <https://github.com/ocaml/ocaml/issues/2229> [#2237] <https://github.com/ocaml/ocaml/issues/2237> [#8582] <https://github.com/ocaml/ocaml/issues/8582> [#2265] <https://github.com/ocaml/ocaml/issues/2265> [#2268] <https://github.com/ocaml/ocaml/issues/2268> [#2280] <https://github.com/ocaml/ocaml/issues/2280> [#2281] <https://github.com/ocaml/ocaml/issues/2281> [#2283] <https://github.com/ocaml/ocaml/issues/2283> [#2284] <https://github.com/ocaml/ocaml/issues/2284> [#2286] <https://github.com/ocaml/ocaml/issues/2286> [#2291] <https://github.com/ocaml/ocaml/issues/2291> [#2292] <https://github.com/ocaml/ocaml/issues/2292> [#2308] <https://github.com/ocaml/ocaml/issues/2308> [#7878] <https://github.com/ocaml/ocaml/issues/7878> [#8542] <https://github.com/ocaml/ocaml/issues/8542> [#8598] <https://github.com/ocaml/ocaml/issues/8598> ◊ Compiler distribution build system:• [#2267]: merge generation of header programs, also fixing parallel build on Cygwin. (David Allsopp, review by Sébastien Hinderer)
• [#8514]: Use boot/ocamlc.opt for building, if available. (Stephen
Dolan, review by Gabriel Scherer) [#2267] <https://github.com/ocaml/ocaml/issues/2267> [#8514] <https://github.com/ocaml/ocaml/issues/8514> ◊ Bug fixes:• [#8864], [#8865]: Fix native compilation of left shift by (word_size - 1) (Vincent Laviron, report by Murilo Giacometti Rocha, review by
Xavier Leroy)• [#2296]: Fix parsing of hexadecimal floats with underscores in the
exponent. (Hugo Heuzard and Xavier Leroy, review by Gabriel Scherer)• [#8800]: Fix soundness bug in extension constructor inclusion (Leo
White, review by Jacques Garrigue)• [#8848]: Fix x86 stack probe CFI information in caml_c_call and
caml_call_gc (Tom Kelly, review by Xavier Leroy)• [#7156], [#8594]: make top level use custom printers if they are
available (Andrew Litteken, report by Martin Jambon, review byNicolás Ojeda Bär, Thomas Refis, Armaël Guéneau, Gabriel Scherer,
David Allsopp) • [#3249]: ocamlmklib should reject .cmxa files (Xavier Leroy)• [#7937], [#2287]: fix uncaught Unify exception when looking for type
declaration (Florian Angeletti, review by Jacques Garrigue)• [#8610], [#8613]: toplevel printing, consistent deduplicated name for types (Florian Angeletti, review by Thomas Refis and Gabriel
Scherer, reported by Xavier Clerc)• [#8635], [#8636]: Fix a bad side-effect of the -allow-approx option of ocamldep. It used to turn some errors into successes (Jérémie
Dimino) • [#8701], [#8725]: Variance of constrained parameters causesprincipality issues (Jacques Garrigue, report by Leo White, review
by Gabriel Scherer) • [#8777](partial): fix position information in some polymorphicvariant error messages about missing tags (Florian Angeletti, review
by Thomas Refis)• [#8779], more cautious variance computation to avoid missing cmis (Florian Angeletti, report by Antonio Nuno Monteiro, review by Leo
White) • [#8810]: Env.lookup_module: don't allow creating loops (Thomas Refis, report by Leo White, review by Jacques Garrigue)• [#8862], [#8871]: subst: preserve scopes (Thomas Refis, report by
Leo White, review by Jacques Garrigue)• [#8921], [#8924]: Fix stack overflow with Flambda (Vincent Laviron,
review by Pierre Chambart and Leo White, report by Aleksandr Kuzmenko)• [#8944]: Fix "open struct .. end" on clambda backend (Thomas Refis,
review by Leo White, report by Damon Wang and Mark Shinwell) [#8864] <https://github.com/ocaml/ocaml/issues/8864> [#8865] <https://github.com/ocaml/ocaml/issues/8865> [#2296] <https://github.com/ocaml/ocaml/issues/2296> [#8800] <https://github.com/ocaml/ocaml/issues/8800> [#8848] <https://github.com/ocaml/ocaml/issues/8848> [#7156] <https://github.com/ocaml/ocaml/issues/7156> [#8594] <https://github.com/ocaml/ocaml/issues/8594> [#3249] <https://github.com/ocaml/ocaml/issues/3249> [#7937] <https://github.com/ocaml/ocaml/issues/7937> [#2287] <https://github.com/ocaml/ocaml/issues/2287> [#8610] <https://github.com/ocaml/ocaml/issues/8610> [#8613] <https://github.com/ocaml/ocaml/issues/8613> [#8635] <https://github.com/ocaml/ocaml/issues/8635> [#8636] <https://github.com/ocaml/ocaml/issues/8636> [#8701] <https://github.com/ocaml/ocaml/issues/8701> [#8725] <https://github.com/ocaml/ocaml/issues/8725> [#8777] <https://github.com/ocaml/ocaml/issues/8777> [#8779] <https://github.com/ocaml/ocaml/issues/8779> [#8810] <https://github.com/ocaml/ocaml/issues/8810> [#8862] <https://github.com/ocaml/ocaml/issues/8862> [#8871] <https://github.com/ocaml/ocaml/issues/8871> [#8921] <https://github.com/ocaml/ocaml/issues/8921> [#8924] <https://github.com/ocaml/ocaml/issues/8924> [#8944] <https://github.com/ocaml/ocaml/issues/8944> OCaml Training 5-6 and 7-8 November 2019 at OCamlPro ════════════════════════════════════════════════════ Archive: <https://sympa.inria.fr/sympa/arc/caml-list/2019-09/msg00020.html> Muriel SHAN SEI FAN announced ─────────────────────────────In our endeavour to encourage professional programmers to understand and use OCaml, OCamlPro will be giving 2 training sessions, in French,
in our Paris offices: 1) OCaml Beginner course for professional programmers (5-6 Nov) 2) OCaml Expertise (7-8 Nov).The "Expert" OCaml course is for already experienced OCaml programmers to better understand advanced type system possibilities (objects, GADTs), discover GC internals, write "compiler-optimizable" code. These sessions are also an opportunity to come discuss with our OPAM & Flambda lead developers and core contributors in Paris. Training in English can also be organized, on-demand. Do not hesitate pass the
word. Links: • <http://www.ocamlpro.com/training-ocamlpro/> • <http://www.ocamlpro.com/course-ocaml-development/> • <http://www.ocamlpro.com/course-ocaml-expert/> • Register link: <http://www.ocamlpro.com/forms/preinscriptions-formation-ocaml/> Cheers, Muriel PS: Note that this complements the excellent OCaml MOOC fromUniversité Paris-Diderot and the learn-OCaml platform of the OCaml
Software Foundation. Arch Linux installer written in OCaml ═════════════════════════════════════ Archive: <https://discuss.ocaml.org/t/arch-linux-installer-written-in-ocaml/4388/1> Darren announced ──────────────── I'm sharing the WIP [project] on the off chance it's interesting/useful to someone. [project] <https://github.com/darrenldl/linux-laptop-salt-hard> What ╌╌╌╌This installer written in OCaml allows installing Arch Linux with
optional disk encryption (where all key files placements, bootparameters adjustment etc are adjusted for you). The installer aims to
be somewhat smart and hassle free to use. Right now• It recognises whehter your Arch Linux live CD is running in BIOS or
EFI mode, and adjusts prompts/partitioning accordingly (nottechnically difficult at all, but just so you know it does that) • Handles optional disk encryption, with encrypted boot (haven't added
code for toggling boot partition encryption yet) • Allows two disk layout schemes atm 1. use a single disk, installer does partitioning for you2. you tell installer partitions for `/', `/boot' and `/efi' if in
EFO mode, and installer use those info instead
WIP
• Installation of SaltStack files (for package management) and
other
helper scripts • Section below gives more context on these things TODO • Resumable installation (add logging etc)• Static config file support (so installation is fully automated)
• Add disk layout scheme where it's system partition + USB key • Whatever is missing from the original script Context ╌╌╌╌╌╌╌This installer is essentially a rewrite of the install script I've
been using for a while.I especially needed an semi-automated solution to installing Arch Linux as I was using a encrypted USB key + encrypted system partition setup, where manual installation is error prone and time consuming.
The install script was thus born, written in bash, accompanied by salt files for package management, and various helper scripts for easier
handling of the USB key in day-to-day operations. This is all fine and dandy until I wanted to have different disklayout, and pick whether I want encryption or not. Bash script is not
terribly good for these somewhat decision/logic heavy tasks for obvious reasons. And so rewrite in OCaml began, and stuck with OCaml even afterconsidering various other choices (e.g. elvish, xonsh, fish, python,
racket). Intention ╌╌╌╌╌╌╌╌╌The code aims to facilitate customisation (make a copy and adjust things your way) by providing a sane starting point, but does not aim to provide a proper "library" type of code base due to the somewhat volatile nature of Arch, and assumptions made may not be directly
portable to other distros. Navigation ╌╌╌╌╌╌╌╌╌╌ • `scripts/'• [`setup.sh'] is the original bash installer script, which this
installer is based on
• remaining files are helpers, and misc scripts
• `saltstack/'
• SaltStack files for package management
• `installer_ml/' contains the OCaml installer code
• `src/'
• [`installer.ml'] somewhat show cases the intended high
level
use, the install workflow is specified here
• [`disk_layout.ml'] handles formatting, LUKS setup,
mounting,
unmounting of partitions etc
• [`task_book.ml'] facilitates high level task registration,
used
in `installer.ml'
• remainders are helper code largely
[`setup.sh']
<https://raw.githubusercontent.com/darrenldl/linux-laptop-salt-hard/master/scripts/setup.sh>
[`installer.ml']
<https://raw.githubusercontent.com/darrenldl/linux-laptop-salt-hard/master/installer_ml/src/installer.ml>
[`disk_layout.ml']
<https://raw.githubusercontent.com/darrenldl/linux-laptop-salt-hard/master/installer_ml/src/disk_layout.ml>
[`task_book.ml']
<https://raw.githubusercontent.com/darrenldl/linux-laptop-salt-hard/master/installer_ml/src/task_book.ml>
TL;DR
╌╌╌╌╌
I wrote a Arch installer in OCaml, thought it's pretty neat.
gasche asked and Darren replied
───────────────────────────────
> Sounds very cool!
Thanks!
> Do you think there is potential for adoption within the Arch
community?
Yes, but definitely not widespread, there are two main reasons.
For people who like to build their system programmatically
╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
The language choice is very niche to begin with - OCaml is
definitely
not a popular choice (if is one to begin with) for system administration.For initial bootstrapping, most other langs are better choices: rich
stdlib is desirable for the initial phase, good handling of interprocess communication, easy access to regex (maybe not asefficient efficient), easy text file manipulation (a lot of formats
supported in stdlib or ecosystem etc).So overall Python, Ruby, Racket are better for this phase. Especially
since there are system administration frameworks in Python(e.g. [Fabric]) and in Ruby (the name escaped me). I stuck with OCaml since my brain can't process more than a hundred lines of code in
dynamically typed languages.So the targeted audience is quite limited - one that knows OCaml, the distro's native installer doesn't work well enough and thus interested
in building their own installer, and does not already have their favourite installer. [Fabric] <https://www.fabfile.org/> Arch overall promotes customisation ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌So most people have their own installers. This is especially true when
Arch deprecated the official installer some years ago.So sticking to mine as is probably doesn't make too much sense to most people. The intention was definitely allowing other people to use it
as a template for making their own OCaml installer to begin with anyway.> What are other people using, and could you convince them to > migrate
to your installer (and help maintain it)? Some of the reasons mentioned in above section carry over.Due to Arch's philosophy on customisation, actively convincing others to use my installer would be close to convincing someone to use your
favourite editor and abandon theirs.In any case, I am the primary beneficiary I had in mind, so lack of
adoption would not prevent me from maintaining it. Being able toreinstall your Linux willy-nilly with full disk encryption, and giving you a fresh but essentially identical copy of your current install
(via package management + dotfiles management), that's gold.*EDIT*: One extra reason is maybe just to demonstrate writing one in OCaml is feasible, as it wasn't quite obvious what the scope of work
was when I first started writing. Anton Kochkov said ──────────────────You might want to check also the [0install] which is also was ported to OCaml from Python, see [their GitHub repository]. Though judging by their repositories activity, they seem abandoned OCaml version and thrown all resources to the C#/.NET version in [0install-dotnet].
[0install] <https://0install.net/> [their GitHub repository] <https://github.com/0install/0install> [0install-dotnet] <https://github.com/0install/0install-dotnet> Thomas Leonard replied ──────────────────────> Though judging by their repositories activity, they seem > abandoned
OCaml version and thrown all resources to the C#/.NET versionWell, this is the problem with OCaml. When 0install was written in Python, I did frequent bug-fix releases. Now it's in OCaml, there's no need to do that. e.g. there were 8 Python releases in 2012 vs 1 OCaml
release last year. I prefer it that way, but it's bad for the project's metrics.There is no directing of resources. Bastian Eicher did the C# version before and is still doing it now (though more of it is now hosted in the main github org and we just merged the two sets of documentation
to make <http://docs.0install.net/>). Online programming playground ═════════════════════════════ Archive: <https://discuss.ocaml.org/t/online-programming-playground/4391/1> Vishal Rana announced ─────────────────────I wanted to shared [https://code.labstack.com/ocaml], an online OCaml
programming playground. I hope you will find it useful.[https://code.labstack.com/ocaml] <https://code.labstack.com/ocaml>
A look back on OCaml 4.* ════════════════════════Archive: <https://discuss.ocaml.org/t/a-look-back-on-ocaml-4/4397/1>
Thomas Blanc announced ────────────────────── To celebrate the 0th anniversary of the 4.09.0 release, OCamlProdecided to look back at how far the language and standard library got
since 3.12.If you want to feel old and nostalgic, or if you want see what your elders had to put up with before, feel free to check out [our blog].
[our blog] <http://www.ocamlpro.com/2019/09/20/a-look-back-on-ocaml/>
Multicore prerequisite patches appearing in released OCaml compilers now
════════════════════════════════════════════════════════════════════════ Archive: <https://discuss.ocaml.org/t/multicore-prerequisite-patches-appearing-in-released-ocaml-compilers-now/4408/1> Anil Madhavapeddy announced ───────────────────────────The release of OCaml 4.09.0 is particularly significant for us at OCaml Labs, as it represents a phase shift in our development efforts towards integrating multicore parallelism into the language. For the past few years, we have been [implementing multicore as a branch] based off released versions of the compiler. We finished rebasing it
to [OCaml 4.06.1] in April and since then have been working on upstreaming a series of incremental changes to OCaml itself.OCaml 4.09.0 is the first such release in which multicore patches are appearing in released versions of the compiler. This is _not_ the
full multicore feature set, but rather the prerequisites tointroducing changes required towards introducing parallelism into the
runtime. You can now expect to see a regular set of incrementalchanges towards multicore in every release of OCaml as we ramp up our
upstreaming efforts. One decision we have taken recently is to spend our time onupstreaming changes in favour of further rebases to more recently versions of the compiler. If someone does have a pressing need for a rebase to OCaml 4.08 or 4.09, then please get in touch with me – but bear in mind that it's a significant amount of work and so will need
to be justified with a usecase.In the meanwhile, here's a summary of what some of those patches are,
and what to expect in future releases: [implementing multicore as a branch] <https://github.com/ocaml-multicore/ocaml-multicore/wiki>[OCaml 4.06.1] <https://twitter.com/kc_srk/status/982165248206491648>
4.09.0 ╌╌╌╌╌╌• In the upcoming multicore GC, object headers (tags and lengths) are immutable due to multiple threads scanning the heap simultaneously; any mutations could violate heap invariants in another thread and
cause corruption. Therefore, `Obj.truncate' ([#2279]) and `Obj.set_tag' ([#1725]) have now been deprecated, and all uses removed from the standard library.• Values can be passed from OCaml to C by registering them under a known name using the `Callback.register' function. They can later
be retrieved from C using `caml_named_value', which returns a`value*' that can then later be dereferenced. OCaml 4.09.0 modifies the C return type to `const value*' to indicate that the C code cannot use the pointer that is returned to mutate the value that is registered ([#2293]). The ability to mutate a value using the raw pointer returned by `caml_named_value' is incompatible with the
upcoming multicore GC, and rarely (never?) used in existing single-core OCaml code. [#2279] <https://github.com/ocaml/ocaml/pull/2279> [#1725] <https://github.com/ocaml/ocaml/pull/1725> [#2293] <https://github.com/ocaml/ocaml/pull/2293> Ongoing for 4.10.0~dev ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌This is the subsequent release that is branching imminently now that
OCaml [4.09.0 has been released].• Variables that are global in the OCaml runtime need to be duplicated per-domain in multicore, since each parallel thread of execution maintains its own table of domain local variables. OCaml 4.09.0
moves all such global C variables into a "domain state" table([#8713]). While the change does not introduce any API changes, it significantly alters code generation by reserving a register that was previously used as the exception pointer in every CPU backend for quickly accessing the domain state table. It is therefore a syntactically heavy change, but shouldn't modify the semantics of
your code. If you do notice any oddnesses when testing OCaml 4.10~dev when it is released as a beta, please do report a reproduction case upstream.• (bonus change) While emerging from deep in a rabbit hole from fixing
thread stack overflow detection and reentrant marshalling byensuring that allocation functions do not trigger OCaml callbacks when invoked from C, it was discovered that major GC hooks could also interact with the GC heap. This is now forbidden ([#8711]) in OCaml 4.09.0. There was no code found in the wild that did not already conform to this restriction, and it is generally safer this
way for the multicore GC as well. [4.09.0 has been released] <https://discuss.ocaml.org/t/ocaml-4-09-0-released/4384> [#8713] <https://github.com/ocaml/ocaml/pull/8713> [#8711] <https://github.com/ocaml/ocaml/pull/8711> Ongoing for 4.11.0~dev ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌As 4.10 is about to be branched, we are working away on the following
next set of features to push upstream into OCaml 4.11: • Better safe points ([#187]) • Tracing and deprecating the instrumented runtime• Converging on the representation of closures in bytecode and native
code. • Modifying GC colors to suit multicore.As always, these chunks of ongoing work are subject to change as the
technical design process is quite iterative and dependent on benchmarking results, but are hopefully useful for you to know![#187] <https://github.com/ocaml-multicore/ocaml-multicore/issues/187>
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.schm...@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/>
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