[cwn] Attn: Development Editor, Latest OCaml Weekly News
Alan Schmitt
alan.schmitt at polytechnique.org
Tue Sep 24 05:41:32 PDT 2019
Hello
Here 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 would
generate, 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-date
cheat-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 opam
cheat-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 SAS
PS: 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 in
caml_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 in
opam. 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 an
extensible 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 remove
functions 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]. Correctly
position [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 by
Nicolás 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 causes
principality issues (Jacques Garrigue, report by Leo White,
review
by Gabriel Scherer)
• [#8777](partial): fix position information in some polymorphic
variant 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 from
Université 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, boot
parameters 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 (not
technically 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 you
2. 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 disk
layout, 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 after
considering 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 as
efficient 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 to
reinstall 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 version
Well, 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, OCamlPro
decided 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 to
introducing changes required towards introducing parallelism
into the
runtime. You can now expect to see a regular set of incremental
changes 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 on
upstreaming 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 by
ensuring 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.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/>
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