OCaml Weekly News

There is now a new library MlFront_Top with a build tool mlfront-top that will generate self-contained OCaml toplevel script files with parallelism based on @c-cube's moonpool library:

.
├── AcmeWidgets_Std/
│   ├── JobsA1.ml
│   └── JobsA2.ml
└── BobBuilder_Std/
    └── JobsB.ml

$ mlfront-top -o buildscript.ml

$ ocaml buildscript.ml -j 2 -native
  legend: -> start | <- finish
     directory create: target/
     file create: target/AcmeWidgets_Std.ml
     link create: AcmeWidgets_Std/JobsA1.ml -> target/AcmeWidgets_Std__JobsA1.ml
     link create: AcmeWidgets_Std/JobsA2.ml -> target/AcmeWidgets_Std__JobsA2.ml
     link create: BobBuilder_Std/JobsB.ml -> target/BobBuilder_Std__JobsB.ml
  -> compile: AcmeWidgets_Std.JobsA1
  -> compile: AcmeWidgets_Std.JobsA2
  <- compile: AcmeWidgets_Std.JobsA1
  <- compile: AcmeWidgets_Std.JobsA2
  -> compile: AcmeWidgets_Std
  <- compile: AcmeWidgets_Std
  -> compile: BobBuilder_Std.JobsB
  <- compile: BobBuilder_Std.JobsB
  -> executable create: BobBuilder_Std.JobsB
  <- executable create: BobBuilder_Std.JobsB
  done.

$ target/BobBuilder_Std.JobsB
I am an A1!
I am an A2!
I am a B!

It requires the ocaml binary and ocamlc or ocamlopt. The complete example is at https://gitlab.com/dkml/build-tools/MlFront/-/blob/0.4.0-6/tests/MlFront_Top/jobs.t/run.t.

Today I want to tell you about new version of Rpmfile library. Rpmfile is a library for reading metadata from RPM packages. Originally Rpmfile's parser (reader) used Angstrom for parsing. And in the new release added new modern Eio-based reader.

Globally, the project is now split into four packages: rpmfile, which contains signatures and implementation-independent functions, rpmfile-unix with the original Angstrom parser, and rpmfile-eio (with rpmfile-cli) written using Eio.

Here is a working first version (with warts) of a ppxlib to yojson converter, am still testing it but the hello world is working, I have tried multiple times to get this to work, and finally settled on the import route to override the type system. code here: https://github.com/meta-introspector/ocaml-libppx-import-yojson-introspector

example snippet

{
  "pexp_desc": [
    "Pexp_constant",
    [
      "Pconst_string",
      "Hello, World!"
    ]
  ]
}

Just wanted to share some of the work the Dune has been up to lately re: the Developer Preview we announced here :) – we'll be using this thread to share more updates as things go.

As always, we hold our Dune Developer meetings in public and you're more than welcome to subscribe to our public Calendar (Google, iCal)

This month's meeting is scheduled for tomorrow, [date=2024-08-20 time=17:00:00 timezone="Europe/London"]!

The meeting agenda thus far is to discuss the following:

• 5.2 Bump Progess
  • Auto-generate AST pattern code and labelled arguments (e.g. value_binding ~constraint_:none but no positional argument?)
  • Ast_helper.Exp.function_ deprecation
  • opam-repository overlay for 5.2 AST bump
• Issues in migrations
  • Bumping the AST has uncovered issues in migrating code up and down the internal ppxlib ASTs – would be good to discuss this and also how to mitigate this going forward.
• Documentation
  • Great user feedback from Ppxlib: Getting the original definition of typ_constr like type_declaration from core_type of ptyp_constr which we should take onboard and work into https://github.com/ocaml-ppx/ppxlib/issues/324
• Some carry over items from last month
  • In general what is the medium term goals for ppxlib? Mostly maintenance and bumping the AST/keeping up with compiler releases?

The meeting will be hosted on google meet here: https://meet.google.com/yxw-ejnu-cju

Everyone is very welcome to join! :camel:

I just published the second part of my series, so I updated the topic.

Let me know when notifications become too noisy :slight_smile:

Hi! The next public dune dev meeting will be held on 2024-08-21, 10am CEST. Please feel free to let me know any topics you'd like us to discuss and I'll update the meeting notes. The zoom link for the meeting is: https://us06web.zoom.us/j/85096877776?pwd=cWNhU1dHQ1ZNSjZuOUZCQ0h2by9Udz09

Here are links from many OCaml blogs aggregated at the ocaml.org blog.

• The new Tar release, a retrospective