OCamlFormat 0.29.0 • OCaml Changelog

We're happy to announce the release of OCamlFormat 0.29.0.

CHANGES:

Highlight

* Support OCaml 5.5 syntax (#2772, #2774, #2775, #2777, #2780, #2781, #2782, #2783, @Julow) The update brings several tiny changes, they are listed below.
* Update Odoc's parser to 3.0 (#2757, @Julow) The indentation of code-blocks containing OCaml code is reduced by 2 to avoid changing the generated documentation. The indentation within code-blocks is now significative in Odoc and shows up in generated documentation.

Added

Added option letop-punning (#2746, @WardBrian) to control whether punning is used in extended binding operators. For example, the code let+ x = x in ... can be formatted as let+ x in ... when letop-punning=always. With letop-punning=never, it becomes let+ x = x in .... The default is preserve, which will only use punning when it exists in the source. This also applies to let%ext bindings (#2747, @WardBrian).

Support the unnamed functor parameters syntax in module types (#2755, #2759, @Julow)

module type F = ARG -> S

The following lines are now formatted as they are in the source file:

module M : (_ : S) -> (_ : S) -> S = N
module M : S -> S -> S = N
(* The preceding two lines are no longer turned into this: *)
module M : (_ : S) (_ : S) -> S = N

Fixed

Fix dropped comment in (function _ -> x (* cmt *)) (#2739, @Julow)

* cases-matching-exp-indent=compact does not impact begin end nodes that don't have a match inside. (#2742, @EmileTrotignon)

(* before *)
begin match () with
| () -> begin
  f x
end
end
(* after *)
begin match () with
| () -> begin
    f x
  end
end

Ast_mapper now iterates on all locations inside of Longident.t, instead of only some. (#2737, @v-gb)
Remove line break in M with module N = N (* cmt *) (#2779, @Julow)

Internal

Added information on writing tests to CONTRIBUTING.md (#2838, @WardBrian)

Changed

indentation of the end keyword in a match-case is now always at least 2. (#2742, @EmileTrotignon)

(* before *)
begin match () with
| () -> begin
  match () with
  | () -> ()
end
end
(* after *)
begin match () with
| () -> begin
  match () with
  | () -> ()

* use shortcut begin end in match cases and if then else body. (#2744, @EmileTrotignon)

(* before *)
match () with
| () -> begin
    match () with
    | () ->
  end
end
(* after *)
match () with
| () ->
  begin match () with
    | () ->
  end
end

* Set the ocaml-version to 5.4 by default (#2750, @EmileTrotignon) The main difference is that the effect keyword is recognized without having to add ocaml-version=5.3 to the configuration. In exchange, code that use effect as an identifier must use ocaml-version=5.2.
The work to support OCaml 5.5 come with several improvements:
- Improve the indentation of let structure-item with the [@ocamlformat "disable"] attribute. let structure-item means let module, let open, let include and let exception.
- (let open M in e)[@a] is turned into let[@a] open M in e.
- Long let open ... in no longer exceed the margin.
- Improve indentation of let structure-item within parentheses:
```
(* before *)
(let module M = M in
M.foo)
(* after *)
(let module M = M in
 M.foo)
```