OCaml Changelog

The ppxlib team is happy to announce the release of ppxlib.0.32.1.

The main feature of this release is of course the support for the upcoming OCaml 5.2 release. Starting with this version you'll be able to use ppx with the latest compiler.

The feature also comes with a small follow up improvement to the 0.32.0 error reporting changes that simplifies how exception thrown from context free rewriting are handled. The errors will now be inserted where the generated code would have been instead of appended to the whole AST. This should lead to a better error reporting from the compiler as it will now report errors in order of their position in the code.

We'd like to thank the OCaml Software Foundation once again as they funded the vast majority of the work for this release.

The ppxlib dev team is happy to announce the release of ppxlib.0.32.0.

The main feature of this release, implemented by @burnleydev1 during their Outreachy internship, is a huge improvement of the handling of located exceptions raised by ppx-es. Whenever a rewrite of the AST throws such an exception, the ppxlib driver catches it and resumes the rewriting using the latest valid AST it knows of. All caught exceptions are appended to the final AST as [%%ocaml.error ..] nodes. This means the driver returns a valid AST instead of one composed of a single error node corresponding to the first raised exception. This leads to a much better experience for ppx users as merlin now has a valid AST to work with when this happens, allowing it to properly function, reporting all errors, from ppx-es or otherwise. Note that despite this change we still recommend ppx authors to embed errors in the rewritten AST rather than throw exceptions.

The release also comes with a few bug fixes on longident parsing or windows compatibility and a new simplified API for ppx authors using attributes as flags (i.e. attributes without payloads such as [@ignore] for instance).

We'd like to thank our external contributors for this release:

• @burnleydev1 for their improvement of the driver exception handling
• @dianaoigo for their addition of the new attribute flags API
• @jonahbeckford for their fix of the windows compatibility

We'd also like to thank the OCaml Software Foundation who has been funding my work on this release.

We're happy to announce the release of Ppxlib 0.31.0. Shortly after OCaml 5.1.0 has been released, this Ppxlib release fixes a bug in the support of OCaml 5.1.0. Before that bug fix, the warnings about a generative/applicative mismatch between a functor creation and its application introduced by OCaml 5.1.0 were also triggered when that mismatch didn't exist.

Furthermore, the release contains a couple of bug fixes in the context of attributes.

We're also excited about two main enhancements. One allows authors of extension node rewriters to add a path argument to the extension node. That's excellent for hygiene since it allows the PPX to be explicit about modules rather than depending on its scope.

The other main enhancement allows an opt-in for compiler warnings about unused code generated by derivers (warnings w32 and w60). That opting in needs to happen on both sides of the deriver, the writer side and the user side. Opting in to those code warnings will help to clean up unused code, leading to performance improvements in compilation and editor support.

We're excited to announce the release of Ppxlib 0.30.0! It comes with support for OCaml 5.1, various enhancements, and bug fixes.

For PPX writing, Ast_pattern now offers additional utility functions, while metaquot benefits from improved error reporting.

PPX usage sees better compatibility with OCaml trunk, thanks to the Driver's improved Parsetree version recognition. This allows for compatibility with both trunk and stable OCaml versions concurrently.

Finally, this release enhances Ppxlib's compatibility with ReScript, introducing "ns" and "res" as reserved namespaces.