OCaml Changelog

RSS

Official stable release announcements and updates from the OCaml compiler, OCaml infrastructure and the OCaml Platform Tools.

Compiler Platform Editor Support Dune

OCaml-LSP 1.23.1

ocaml-lsp platform editors

We're happy to announce the release of ocaml-lsp-server 1.23.1!

This maintenance release fixes three key issues:

  • Method hover now works: Hovering over object method calls now correctly displays type information instead of showing "No information available"
  • OCamllex files open without errors: Fixed an error that occurred when opening .mll (OCamllex lexer) files in editors like NeoVim
  • Yojson compatibility: Ensures the language server works with both yojson 2.0 and 3.0

Update via opam: opam update && opam upgrade ocaml-lsp-server

For more details, see the related announcement on the Discuss forums!

See full changelog

Fixes

  • Fix hover on method calls not showing the type. (#1553, fixes #1552)
  • Fix error on opening .mll files (#1557)
  • Ensure compatibility with both yojson 2.0 and 3.0. (#1534)

Emacs Integration for OCaml LSP Server: Introducing ocaml-eglot

ocaml-lsp platform editors

TL;DR

ocaml-eglot provides full OCaml language support in Emacs through the Language Server Protocol (LSP) instead of direct Merlin integration. It offers the same features as merlin.el with simplified setup and enhanced capabilities like project-wide search. If you're starting fresh or want a more standardized approach, try ocaml-eglot, which is actively maintained. If your current merlin.el setup works well, you can continue using it.

Quick start: Install ocaml-lsp-server, add ocaml-eglot to your Emacs config, and get the same OCaml development experience with less configuration.

What is ocaml-eglot?

ocaml-eglot connects Emacs to ocaml-lsp-server using the Language Server Protocol, providing a standardized way to get OCaml language support.

Since the recent versions of Emacs (29), eglot, an LSP client, has been shipped with Emacs. However, merlin.el provides more features than LSP (which is designed to be generic), so relying solely on the features of LSP and eglot would limit functionality. Thus, we extended the LSP server to support more features, and ocaml-eglot allows you to benefit from these features in Emacs.

ocaml-eglot is a minor mode. It therefore works in conjunction with a major mode to edit Caml code. Examples of major modes include tuareg, caml-mode and the recent neocaml.

Who Should Use ocaml-eglot?

Use ocaml-eglot if you:

  • Are starting fresh with OCaml
  • If you use or want to use Emacs
  • Want simplified configuration with automatic setup
  • Use multiple editors and want consistent OCaml support
  • Want access to project-wide search and rename features
  • Want to rely on an actively maintained project that evolves over time

If your current setup is working perfectly and is heavily customised, merlin.el will still keep working, so there's no immediate need to migrate. However, for the moment, we don't plan to actively maintain merlin.el -- unless we receive a lot of requests.

Getting Started

Follow the installation instructions in the ocaml-eglot README.

When migrating from merlin.el to ocaml-eglot, your existing keybindings should work immediately!

Features

Error Navigation: Quick jump to next/previous errors

Type Information: Display types under cursor with adjustable verbosity, navigate enclosing expressions

Code Generation: Pattern matching construction, case completion, wildcard refinement via "destruct" feature

Navigation: Jump between language constructs (let, module, function, match), navigate phrases and pattern cases

Search: Find definitions, declarations, and references

For a detailed list of features, see the ocaml-eglot README.

Next Steps

  1. Try the basic setup with an existing OCaml project
  2. Explore all the features of ocaml-eglot
  3. Provide feedback at ocaml-eglot's GitHub Issues

Documentation

Related Releases

On January 17, 2025, ocaml-eglot version 1.0.0 was released, providing a new minor emacs mode to enable the editor features provided by ocaml-lsp-server. Subsequent releases 1.1.0 and 1.2.0 enable support for flycheck as a configurable alternative to flymake (1.0.0 release), Emacs 30.1 support, better user experience and error handling, as well as support for new features.

OCaml-LSP 1.20.1

ocaml-lsp platform editors

We are excited to share the release of OCaml-LSP 1.20.1, which introduces powerful new features and vital bug fixes to improve your development workflow. The new typeSearch request allows you to find values by type signature or polarity, making it easier to locate the functionality you need. Configurable MerlinJump actions and the custom jump request give you more control over code navigation. On the bug fix side, we have tackled issues like file descriptor leaks, enhanced method completion, and cleaned up duplicate responses in selectionRange.

See full changelog

Features

  • Add custom ocamllsp/typeSearch request (#1369)
  • Make MerlinJump code action configurable (#1376)
  • Add custom ocamllsp/jump request (#1374)

Fixes

  • Deactivate the jump code actions by default. Clients can enable them with the merlinJumpCodeActions configuration option. Alternatively, a custom request is provided for ad hoc use of the feature. (#1411)
  • Fix FD leak in running external processes for preprocessing (#1349)
  • Fix prefix parsing for completion of object methods (#1363, fixes #1358)
  • Remove some duplicates in the selectionRange answers (#1368)

Merlin 5.3-502 for OCaml 5.2 and 4.18-414 for OCaml 4.14

merlin platform editors

This release introduces Merlin 5.3-502, compatible with OCaml 5.2, and 4.18-414, compatible with OCaml 4.14. Key updates include EXCLUDE_QUERY_DIR for better file management, resolving exceptions in polarity search,

and stabilizing type-enclosing results. For users of 5.3-502, additional enhancements address path resolution issues, fixes jump to fun functionality, and ensure proper handling of occurrences from hidden source files.

See full changelog

  • merlin binary

    • Respect the EXCLUDE_QUERY_DIR configuration directive when looking for cmt files #1854
    • Fix exception in polarity search (#1858 fixes #1113)
    • Fix type-enclosing results instability. This reverts some overly aggressive deduplication that should be done on the client side. #1864

  • merlin binary (only in 5.3-502)

    • Fix occurrences bug in which relative paths in index files are resolved against the PWD rather than the SOURCE_ROOT #1855
    • Fix jump to fun targets not working (#1863, fixes #1862)
    • Fix occurrences not working when the definition comes from a hidden source file #1865

Merlin 5.2.1-502 for OCaml 5.2 and 4.17.1 for OCaml 5.1 and 4.14

merlin platform editors

We are happy to announce the joint release of Merlin 5.2.1-502 and 4.17.1. This release adds many new features to Merlin including the ability to add hints to a source tree, serch for values using a type signature and expanding PPX annotations to preview their source code. There are also bug fixes for both the Merlin binary and editor modes.

More information can be found in the Discuss announcement.

Contributions are always welcome at Merlin | Issues

See full changelog
  • merlin binary
    • A new WRAPPING_PREFIX configuration directive that can be used to tell Merlin what to append to the current unit name in the presence of wrapping (ocaml/merlin#1788)
    • Add -unboxed-types and -no-unboxed-types as OCaml ignored flags (ocaml/merlin#1795, fixes ocaml/merlin#1794)
    • Destruct: Refinement in the presence of optional arguments (ocaml/merlin#1800 ocaml/merlin#1807, fixes ocaml/merlin#1770)
    • Implement new expand-node command for expanding PPX annotations (ocaml/merlin#1745)
    • Implement new inlay-hints command for adding hints on a source tree (ocaml/merlin#1812)
    • Implement new search-by-type command for searching values by types (ocaml/merlin#1828)
    • Canonicalise paths in occurrences. This helps deduplicate the results and
    • Show more user-friendly paths. (ocaml/merlin#1840)
    • Fix dot-merlin-reader ignoring SOURCE_ROOT and STDLIB directives (ocaml/merlin#1839, ocaml/merlin#1803)
  • editor modes
    • Vim:
      • Fix Python-3.12 syntax warnings in merlin.py (ocaml/merlin#1798)
      • Dead code / doc removal for previously deleted MerlinPhrase command (ocaml/merlin#1804)
    • Emacs:
      • Improve the way that result of polarity search is displayed (#1814)
      • Add merlin-search-by-type, merlin-search-by-polarity and change the behaviour of merlin-search to switch between by-type or by-polarity depending on the query (ocaml/merlin#1828)

OCaml-LSP 1.19.0

ocaml-lsp platform editors

We are pleased to announce the release of OCaml LSP 1.19.0. This version brings official support for OCaml 5.2. It also includes a new custom query to get

documentation and a fix regarding the handling of OCamlFormat processes.

See full changelog

Features

Fixes

  • Kill unnecessary OCamlFormat processes with sigterm rather than sigint or sigkill (ocaml/ocaml-lsp#1343)

OCaml-LSP 1.18.0

ocaml-lsp platform editors

We are pleased to announce the release of OCaml LSP 1.18.0. This version comes with a lot of fixes and new features.

Notable features that are included in this release are:

  • Improved hover behavior with less noisy hovers on some parse tree nodes such as keywords, comments, etc., along with support for hovering over PPX annotations and preview the generated code.
  • Some additional custom queries, particularly TypeEnclosing
  • Folding ifthenelse expressions
  • A new configuration option to control Dune diagnostics
  • Improved document symbols

...and many fixes to a handful of issues.

Feedback is very much welcomed on the the Discuss Announcement post and do not hesistate to report issues in the issue tracker.

See full changelog

Features

  • Introduce a configuration option to control Dune diagnostics. The option is called duneDiganostics, and it may be set to { enable: false } to disable diagnostics. (ocaml/ocaml-lsp#1221)

  • Support folding of ifthenelse expressions (ocaml/ocaml-lsp#1031)

  • Improve hover behavior (ocaml/ocaml-lsp#1245)

    Hovers are no longer displayed on useless parse tree nodes such as keywords, comments, etc.

    Multiline hovers are now filtered away.

    Display expanded PPXs in the hover window.

  • Improve document symbols (ocaml/ocaml-lsp#1247)

    Use the parse tree instead of the typed tree. This means that document symbols will work even if the source code doesn't type check.

    Include symbols at arbitrary depth.

    Differentiate functions / types / variants / etc.

    This now includes PPXs like let%expect_test or let%bench in the outline.

  • Introduce a destruct-line code action. This is an improved version of the old destruct code action. (ocaml/ocaml-lsp#1283)

  • Improve signature inference to only include types for elements that were absent from the signature. Previously, all signature items would always be inserted. (ocaml/ocaml-lsp#1289)

  • Add an update-signature code action to update the types of elements that were already present in the signature (ocaml/ocaml-lsp#1289)

  • Add custom ocamllsp/merlinCallCompatible request (ocaml/ocaml-lsp#1265)

  • Add custom ocamllsp/typeEnclosing request (ocaml/ocaml-lsp#1304)

Fixes

  • Detect document kind by looking at Merlin's suffixes config.

    This enables more LSP features for non-.ml/.mli files. Though it still depends on Merlin's support. (ocaml/ocaml-lsp#1237)

  • Correctly accept the --clientProcessId flag. (ocaml/ocaml-lsp#1242)

  • Disable automatic completion and signature help inside comments (ocaml/ocaml-lsp#1246)

  • Includes a new optional/configurable option to toggle syntax documentation. If toggled on, allows display of syntax documentation on hover tooltips. Can be controlled via environment variables and by GUI for VS code. (ocaml/ocaml-lsp#1218)

  • For completions on labels that the LSP gets from Merlin, take into account whether the prefix being completed starts with ~ or ?. Change the label completions that start with ? to start with ~ when the prefix being completed starts with ~. (ocaml/ocaml-lsp#1277)

  • Fix document syncing (ocaml/ocaml-lsp#1278, ocaml/ocaml-lsp#1280, fixes ocaml/ocaml-lsp#1207)

  • Stop generating inlay hints on generated code (ocaml/ocaml-lsp#1290)

  • Fix parenthesising of function types in SignatureHelp (ocaml/ocaml-lsp#1296)

  • Fix syntax documentation rendering (ocaml/ocaml-lsp#1318)

Merlin 5.1-502 for OCaml 5.2

merlin platform editors

We are pleased to announce the release of Merlin 5.1-502. This is an important release that brings a lot of backend changes and a major new feature: project-wide occurrences queries.

Try it by running dune build @ocaml-index (since dune 3.16.0) and performing a reference query!

More information can be found in the discuss announcement and the wiki.

See full changelog
  • merlin binary
    • Support project-wide occurrences queries using index files (ocaml/merlin#1766)
      • The file format is described in library Merlin_lib.index_format
      • Two new configuration directives are introduced:
        • SOURCE_ROOT that is used to resolve relative paths found in the indexes.
        • INDEX that is used to declare the list of index files Merlin should use when looking for occurrences.
    • A new UNIT_NAME configuration directive that can be used to tell Merlin the correct name of the current unit in the presence of wrapping (ocaml/merlin#1776)
    • Perform incremental indexation of the buffer when typing. (ocaml/merlin#1777)
    • merlin-lib.commands: Add a find_command_opt alternative to find_command that does not raise (ocaml/merlin#1778)
    • Prevent uid clashes by not returning PWO for defs located in the current interface file (ocaml/merlin#1781)
    • Reset uid counters when restoring the typer cache so that uids are stable across re-typing (ocaml/merlin#1779)
    • Improve the behavior on occurrences when the cursor is on a label / constructor declaration (ocaml/merlin#1785)
  • editor modes
    • emacs: add basic support for project-wide occurrences (ocaml/merlin#1766)
    • vim: add basic support for project-wide occurrences (ocaml/merlin#1767, @Julow)

Merlin 4.16 for OCaml 4.14 and 5.1

merlin platform editors

We are pleased to announce the release of Merlin 4.16-414 and 4.16-501.

These releases expose additional functions for packages using merlin-lib that need to manually parse merlin commands.

See full changelog
  • merlin binary
    • Addition of a merlin-lib.commands library which disassociates the execution of commands from the new_protocol, from the binary, allowing it to be invoked from other projects (ocaml/merlin#1758)
    • merlin-lib.commands: Add a find_command_opt alternative to find_command that does not raise (ocaml/merlin#1778)

Merlin 4.15 for OCaml 4.14 and 5.1

merlin platform editors

We are pleased to announce the release of Merlin 4.15-414 and 4.15-501.

These releases bring a handful of bug fixes and improvements, notably to the destruct feature, that were already released for OCaml 5.2 in Merlin 5.0-502.

See full changelog
  • merlin binary
    • destruct: Removal of residual patterns (ocaml/merlin#1737, fixes ocaml/merlin#1560)
    • Do not erase fields' names when destructing punned record fields (ocaml/merlin#1734, fixes ocaml/merlin#1661)
    • Ignore SIGPIPE in the Merlin server process (ocaml/merlin#1746)
    • Fix lexing of quoted strings in comments (ocaml/merlin#1754, fixes ocaml/merlin#1753)
    • Improve cursor position detection in longidents (ocaml/merlin#1756)

Merlin 5.0

merlin platform editors

We are pleased to announce the release of Merlin 5.0-502!

This release brings official support for OCaml 5.2. Substantial backend changes were required to adapt to this release, especially for features such as occurrences and get-documentation. Do not hesitate to report any suspicious behavior in the issue tracker!

This release also fixes a handful of issues, two of them improving the behaviour of Merlin's destruct feature.

See full changelog
  • merlin binary
    • Support for OCaml 5.2 (#1757)
    • destruct: Removal of residual patterns (#1737, fixes #1560)
    • Do not erase fields' names when destructing punned record fields (#1734, fixes #1661)
    • Ignore SIGPIPE in the Merlin server process (#1746)
    • Fix lexing of quoted strings in comments (#1754, fixes #1753)
    • Improve cursor position detection in longidents (#1756)
    • Addition of a merlin-lib.commands library that disassociates the execution of commands from the new_protocol, from the binary, allowing it to be invoked from other projects (#1758)
    • New occurrences backend: Don't index occurrences when merlin.hide attribute is present. (#1768)
    • Use the new uid_to_decl table in 5.2's CMT files to get documentation. (#1773)

Merlin 4.14

merlin platform editors

We're thrilled to announce the release of Merlin 4.14, a significant update that introduces a suite of enhancements and fixes to improve your OCaml editor experience.

In addition to the improvements and bug fixes in this release, Merlin 4.14 is the first version to support the upcoming OCaml 5.2 compiler.

Some highlights in this release include:

  • Improved Telemetry and Heap Usage Reporting: With the addition of the "heap_mbytes" field in server responses (#1717) and cache stats in telemetry (#1711), developers can now gain deeper insights into Merlin's performance and memory usage. These enhancements are part of our ongoing efforts to improve Merlin's performance profiling capabilities.
  • SyntaxDocument Command: Addressing a common challenge among new users, the new SyntaxDocument command (#1706) enables you to find detailed information about the syntax element under the cursor directly from your editor. This feature aims to facilitate learning and code readability by providing instant access to syntax descriptions, making it easier for developers to familiarize themselves with OCaml's syntax.

Happy coding!

See full changelog
  • merlin binary
    • Add a "heap_mbytes" field to Merlin server responses to report heap usage (#1717)
    • Add cache stats to telemetry (#1711)
    • Add new SyntaxDocument command to find information about the node under the cursor (#1706)
    • Fix FLG -pp ppx.exe -as-pp/-dump-ast use of invalid shell redirection when direct process launch on Windows. (#1723, fixes #1722)
    • Add a query_num field to the ocamlmerlin responses to detect server crashes (#1716)
    • Jump to cases within a match statement (#1726)
    • Jump to module-type (#1728, partially fixes #1656)
    • Exposes stable functions for configuration handling and pattern variable destruction. (#1730)
  • editor modes
    • vim: load merlin under the ocamlinterface and ocamllex filetypes (#1340)
    • Fix merlinpp not using binary file open (#1725, fixes #1724)

OCaml-LSP 1.17.0

ocaml-lsp platform editors

We are pleased to announce the release of OCaml LSP 1.17.0. This version comes packed with fixes and new features.

Notable features that come in this release include:

  • Compatibility with Odoc 2.3.0: This version is fully compatible with Odoc 2.3.0, introducing support for the latest syntax features like tables and "codeblock output."
  • New Actions for Code Cleanup: You can now mark or remove unused elements such as 'open', types, for loop indexes, modules, match cases, 'rec', and constructors, making your code cleaner and more efficient.
  • Auto-completion for 'in' Keyword: To address the long standing issue of the in keyword completing to other terms in the editor, we've added auto-completion for this keyword in OCaml LSP. Typing in will now only suggest auto completion for the in keyword.
See full changelog

Fixes

  • Fix missing super & subscripts in markdown documentation. (#1170)
  • Do not invoke dune at all if --fallback-read-dot-merlin flag is on. (#1173)
  • Fix semantic highlighting of infix operators that contain '.'. (#1186)
  • Disable highlighting unit as an enum member to fix comment highlighting bug. (#1185)
  • Improve type-on-hover and type-annotate efficiency by only formatting the type of the first enclosing. (#1191, #1196)
  • Fix the encoding of URI's to match how vscode does it (#1197)
  • Fix parsing of completion prefixes (#1181)

Features

  • Compatibility with Odoc 2.3.0, with support for the introduced syntax: tables, and "codeblock output" (#1184)
  • Display text of references in doc strings (#1166)
  • Add mark/remove unused actions for open, types, for loop indexes, modules, match cases, rec, and constructors (#1141)
  • Offer auto-completion for the keyword in (#1217)

Merlin 4.13

merlin platform editors

We're happy to announce the release of Merlin 4.13. This release comes with a number of bug fixes to the Merlin binary.

It also introduces a new -cache-lifespan flag that can be used to set cache invalidation periods. This flag allows for fine-tuning of cache invalidation periods, enabling users to customize Merlin's internal configurations for optimal performance in various project contexts.

Additionally, this release includes several improvements in editor modes. For more details, we encourage you to delve into the full changelog.

See full changelog
  • merlin binary
    • Fix a follow-up issue to the preference of non-ghost nodes introduced in #1660 (#1690, fixes #1689)
    • Add -cache-lifespan flag, that sets cache invalidation period. (#1698, #1705)
    • Fix Merlin locate not fallbacking on the correct file in case of ambiguity (@goldfirere, #1699)
    • Fix Merlin reporting errors provoked by the recovery itself (#1709, fixes #1704)
  • editor modes
    • vim: load merlin when Vim is compiled with +python3/dyn (e.g. MacVim)
    • emacs: highlight only first error line by default (#1693, fixes #1663)

Merlin 4.12

merlin platform editors

Merlin 4.12 is a small patch release fixing regressions introduced in previous versions.

See full changelog
  • merlin binary
    • Fix issue with let operators and tuples (ocaml/merlin#1684, fixes ocaml/merlin#1683, fixes ocaml/ocaml-lsp#1182)
    • Fix an issue causing Merlin locate queries to hang (ocaml/merlin#1686, fixes ocaml/ocaml-lsp#1192)

Merlin 4.11

merlin platform editors

We are pleased to announce the release of Merlin 4.11 for OCaml 4.14.1, 5.0, and 5.1.

This release brings official support for OCaml 5.1 and introduces some changes to Emacs' default bindings proposed by the community:

  • Unbind C-c C-r (to avoid shadowing tuareg-eval-region) and bind C-c C-v instead to merlin-error-check;
  • Rebind C-c C-d to merlin-document and bind C-c M-d and C-c | instead to merlin-destruct;
  • Bind C-u C-c C-t to merlin-type-expr.

Thanks to everyone involved!

See full changelog
  • Merlin binary
    • Improve error messages for missing configuration reader (ocaml/merlin#1669)
    • Fix regression causing crash when using PPXs under Windows (ocaml/merlin#1673)
    • Fix confusion between aliased modules and module types (ocaml/merlin#1676, fixes ocaml/merlin#1667)
    • Ignore hidden branches when listing occurrences (ocaml/merlin#1677, fixes ocaml/merlin#1671)
  • Editor modes
    • Emacs: fix/improve keybindings (ocaml/merlin#1668, fixes ocaml/merlin#1386): Unbind C-c C-r (to avoid shadowing tuareg-eval-region) and bind C-c C-v instead to merlin-error-check; rebind C-c C-d to merlin-document and bind C-c M-d and C-c | instead to merlin-destruct; bind C-u C-c C-t to merlin-type-expr.
    • Emacs: remove use of obsolete defadvice macro (ocaml/merlin#1675)

Merlin 4.10

merlin platform editors

We're thrilled to announce the release of Merlin 4.10, which comes with many bug fixes and improvements.

One of the standout features of this release is the significantly enhanced support for binding operators like let+ and and+. You'll find that the results from type-enclosing on expressions that contain let bindings are now more precise.

See full changelog
  • merlin binary
    • Constrain socket path buffer size to avoid build warnings (#1631)
    • Handle concurrent server start (#1622)
    • Omit module prefixes for constructors and record fields in the construct command (#1618). Prefixes are still produced when warning 42 (disambiguated name) is active.
    • Correctly invalidate PPX cache when pipeline ran partially (#1650, fixes #1647)
    • Prevent short-path from looping in some cases related to recursive type definitions (#1645)
    • Support parsing negative numbers in sexps (#1655)
    • Fix construct not working with inline records (#1658)
    • Improve behavior of type-enclosing on let/and operators (#1653)
    • Fix occurrences of extension constructors (#1662)
    • Improve node selection when ghosts are present (#1664, fixes #1660)
  • editor modes
    • emacs: call merlin-client-logger with "interrupted" if the merlin binary itself is interrupted, not just the parsing of the result (#1626).
    • emacs: merlin-construct, with a prefix argument, now includes local values in the completion options. Alternatively, this behavior can be enabled permanently by customizing merlin-construct-with-local-values (#1644)
    • emacs: add support for opam-switch-mode (#1654, fixes #1591). See https://github.com/ProofGeneral/opam-switch-mode

OCaml-LSP 1.16.2

ocaml-lsp platform editors

We've released OCaml LSP 1.16.2 with a fix that was introduced in 1.16.1 that prevented users from using preprocessor such as CPPO.

See full changelog

Fixes

  • Fix file permissions used when specifying output files of pp and ppx. (ocaml-lsp#1153)

OCaml-LSP 1.16.1

ocaml-lsp platform editors

We're thrilled to announce the release of OCaml LSP 1.16.1! 🎉

This release comes with new "Extract local" and "Extract function" code actions to easily refactor your code.

We've also disabled code lenses by default following user feedback. You can follow the discussion on GitHub.

This release is also the first OCaml LSP release to use upstream Merlin. Among other things, this means that it is compatible with all the OCaml versions supported by Merlin: currently OCaml 4.14 and 5.0.0.

We're also releasing numerous bug fixes, including:

  • A fix to the integration with Dune RPC on Windows, which, alongside Dune 3.9.0, makes OCaml LSP report Dune errors to the editors with Dune watch mode enabled.
  • Minor improvements to the Odoc <-> Markdown conversion to return better function documentation on the editor.

And much more! Read the full changelog for a complete list of improvements and bug fixes.

See full changelog

Features

  • Add "Remove type annotation" code action. (#1039)
  • Support settings through didChangeConfiguration notification (#1103)
  • Add "Extract local" and "Extract function" code actions. (#870)
  • Depend directly on merlin-lib 4.9 (#1070)

Fixes

  • Support building with OCaml 5.0 and 5.1 (#1150)

  • Disable code lens by default. The support can be re-enabled by explicitly setting it in the configuration. (#1134)

  • Fix initilization of ocamlformat-rpc in some edge cases when ocamlformat is initialized concurrently (#1132)

  • Kill unnecessary $ dune ocaml-merlin with SIGTERM rather than SIGKILL (#1124)

  • Refactor comment parsing to use odoc-parser and cmarkit instead of octavius and omd (#1088)

    This allows users who migrated to omd 2.X to install ocaml-lsp-server in the same opam switch.

    We also slightly improved markdown generation support and fixed a couple in the generation of inline heading and module types.

  • Allow opening documents that were already open. This is a workaround for neovim's lsp client (#1067)

  • Disable type annotation for functions (#1054)

  • Respect codeActionLiteralSupport capability (#1046)

  • Fix a document syncing issue when utf-16 is the position encoding (#1004)

  • Disable "Type-annotate" action for code that is already annotated. (#1037, fixes #1036)

  • Fix semantic highlighting of long identifiers when using preprocessors (#1049, fixes #1034)

  • Fix the type of DocumentSelector in cram document registration (#1068)

  • Accept the --clientProcessId command line argument. (#1074)

  • Accept --port as a synonym for --socket. (#1075)

  • Fix connecting to dune rpc on Windows. (#1080)

Merlin 4.9

merlin platform editors

We are pleased to announce the release of Merlin 4.9 for OCaml 4.14.1 and 5.0.

This maintenance release brings multiple bug fixes and improvements. In particular we identified and patched an important memory consumption issue that could greatly affect Merlin’s performance in heavily functorized projects.

See full changelog
  • merlin binary
    • Allow monadic IO in dot protocol (#1581)
    • Add a scope option to the occurrences command in preparation for the upcoming project-wide-occurrences feature (#1596)
    • Construct bool-typed holes as false instead of true in the construct command, for consistency (#1599).
    • Add a hook to configure system command for spawning ppxes when Merlin is used as a library. (#1585)
    • Implement an all-or-nothing cache for the PPX phase (#1584)
    • Cleanup functors caches when backtracking, to avoid memory leaks (#1609, fixes #1529 and ocaml-lsp#1032)
    • Fix construct results ordering for sum types sand poly variants (#1603)
    • Fix object method completion not working (#1606, fixes #1575)
    • Improve context detection for package types (#1608, fixes #1607)
    • Fix incorrect locations for string literals (#1574)
    • Fixed an issue that caused errors to erroneously alert about missing cmi files (#1577)
    • Prevent destruct from crashing on closed variant types (#1602, fixes #1601)
    • Improve longident parsing (#1612, fixes #945)
  • editor modes
    • emacs: call the user's configured completion UI in merlin-construct (#1598)
  • test suite
    • Add missing dependency to a test using ppxlib (#1583)
    • Add tests for the new PPX phase cache (#1584)
    • Add and update tests for construct ordering (#1603)

Merlin 4.8

merlin platform editors

We are pleased to announce the release of Merlin 4.8 for OCaml 4.14.1 and 5.0.

This maintenance release brings multiple bug fixes and improvements to document fetching, jump-to-definition and type-on-hover for records' labels.

See full changelog
  • merlin binary
    • Update internal typer to match OCaml 4.14.1 release (#1557)
    • Improve type-enclosing behaviour when used on records' labels (#1565, fixes #1564)
    • Restore compatibility with some OCaml compiler's debug flags that were incorrectly rejected by Merlin (#1556)
    • Traverse aliases when jumping to declaration. This matches jump-to-definition's behavior (#1563)
    • Improve locate's behavior in various ill-typed expressions (#1546, fixes #1567 and partially #1543)
    • Correctly traverse patterns when looking for docs in the typedtree (#1572)
    • Get documentation when the declaration or definition is selected (#1542, fixes #1540)
    • On Windows, change to a harmless directory when launching server to avoid locking down current directory (#1569, fixes #1474)
  • test suite
    • Add multiple tests for locate over ill-typed expressions (#1546)
    • Add non-regression tests for other fixes in this release

OCaml-LSP 1.15.0

ocaml-lsp platform editors

On behalf of the ocaml-lsp team, I’m pleased to announce ocaml-lsp-server versions 1.15.0-4.14 and 1.15.0-5.0 for OCaml 4.14 and 5.0, respectively. This is the first time we release ocaml-lsp supporting two compiler versions. We look forward to your feedback.

See full changelog

Features

  • Enable semantic highlighting support by default (#933)

  • Support connecting over pipes and socket. Pipes on Windows aren't yet supported (#946)

    More about communication channels in LSP specification.

  • Re-enable ocamlformat-rpc for formatting code snippets (but not files and not on Windows) (#920, #939)

    One needs to have installed either ocamlformat package version > 0.21.0 or, otherwise, ocamlformat-rpc package. Note that previously ocamlformat-rpc came in a standalone OPAM package, but since ocamlformat version > 0.21.0, it comes within ocamlformat package.

  • Add custom ocamllsp/hoverExtended request (#561)

  • Support utf-8 position encoding clients (#919)

    More about position encoding in LSP specification.

  • Show unwrapped module alias types on hovering over module names. This is due to upgrading to merlin 4.7 and using merlin's verbosity=smart by default (#942)

Fixes

  • Respect the client's completion item resolve and preSelect capabilities (#925, #936)

  • Disable polling for dune's watch mode on Windows and OCaml 4.14.0 (#935)

  • Fix semantic highlighting of "long identifiers," e.g., Foo.Bar.x (#932)

  • Fix syncing of document contents:

    • For ranges that span an entire line (#927)
    • Previously, whole line edits would incorrectly eat the newline characters (#971)

Merlin 4.7

merlin platform editors
See full changelog
  • merlin binary
    • Replace custom "holes" AST nodes by extensions. This restores binary compatibility and fixes issues with PPXs when using typed-holes. (#1503)
    • Do not change temporarily Merlin's cwd when starting a PPX (#1521, fixes #1420)
    • Fix a parsing issue when declaring the (??) custom prefix operator. (#1507, fixes #1506)
    • Fix variant constructors' comments grouping (#1516, @mheiber, fixes #1513)
    • Filter-out duplicates from the enclosing command result (#1512)
    • Add a new verbosity=smart mode for type enclosing that only expand modules' types (#1374, @ulugbekna)
    • Improve locate for labels' declarations in the current buffer. (#1505, fixes #1524)
    • Fix locate on module without implementation (#1522, fixes #1519)
    • Allow program name customization when merlin is used as a library. (#1532)
  • editor modes
    • vim: load the plugin when necessary if it wasn't loaded before (#1511)
    • emacs: xref works from context menus; better highlighting of xref matches; xref recognises operators and binding operators at the cursor position; bad locations are filtered out (#1385, fixes #1410)
    • emacs: update CI for newer releases and fix some warnings (#1454, @mattiase)
  • test suite
    • Add tests for constructors' documentation (#1511)
    • Add test cases for label comment documentation (#1526, @mheiber)
    • Add a test for the enclosing command (#1512)
    • Add tests for interactions between locate and record labels (#1505)
    • Add test showing an issue with locate and implicit transitive deps

OCaml-LSP 1.14.2

ocaml-lsp platform editors
See full changelog

Fixes

  • Fix random requests failing after switching documents (#904, fixes #898)

  • Do not offer related diagnostic information unless the user enables in client capabilities (#905)

  • Do not offer diagnostic tags unless the client supports them (#909)

  • Do not attach extra data to diagnostics unless the client supports this (#910)

  • Use /bin/sh instead of /bin/bash. This fixes ocamllsp on NixOS

OCaml-LSP 1.14.1

ocaml-lsp platform editors
See full changelog

Fixes

  • Fix various server crashes when opening non OCaml/Reason files. Files such as dune, cram, etc. would cause the server to crash. (#884, fixes #871)

  • Ignore unknown tags in merlin configuration to improve forward compatibility with Dune. (#883)

OCaml-LSP 1.14.0

ocaml-lsp platform editors

On behalf of the ocamllsp team, I'm pleased to announce version 1.14.0. This release contains a new code action to help you inline definitions thanks to @jfeser. We look forward to your feedback.

See full changelog

Features

  • Code action for inlining let bindings within a module or expression. (#847)

  • Tag "unused code" and "deprecated" warnings, allowing clients to better display them. (#848)

  • Refresh merlin configuration after every dune build in watch mode (#853)

Fixes

  • Respect showDocument capabilities. Do not offer commands or code actions that rely on this request without client support. (#836)

  • Fix signatureHelp on .mll files: avoid "Document.dune" exceptions

OCaml-LSP 1.12.4

ocaml-lsp platform editors
See full changelog

  • Allow cancellation of workspace symbols requests (#777)

  • Fix unintentionally interleaved jsonrpc IO that would corrupt the session (#786)

  • Ignore SIGPIPE . (#788)

OCaml-LSP 1.12.3

ocaml-lsp platform editors
See full changelog

Fixes

  • Fix a bad interaction between inferred interfaces and promotion code actions in watch mode (#753)

  • Fix URI parsing (#739 fixes #471 and #459)

Merlin 4.6

merlin platform editors
See full changelog
  • merlin binary
    • make most library public and split merlin in two packages: the merlin-lib package that exposes merlin's internals and the merlin package with the frontend. (#1448, #1455, #1457, #1497, @rgrinberg, @tmattio, @kit-ty-kate)
    • Type printing: use best_module_path for paths from Mty_alias (#1470)
    • Attempt at finding the 'real' capitalization of files on windows (#1462 by @mlasson)
    • Use newer Seq-based API of Yojson 2.0, avoiding the need for the deprecated Stream module (#1475 by @Leonidas-from-XIV)
    • unify parsing of MERLIN_LOG (#1480 by @ulugbekna)
    • Fix type deduplication in type-enclosing results (#1483, fixes #1477)
    • Only weakly reduce the shapes to speed up the new Merlin locate implementation. (#1488)
    • Ignore unknown configuration tags from dune configuration provider but not from dot-merlin-reader (#1486)
    • typing recovery: recover at the granularity of core_type (#1484)
  • editor modes
    • add method imenu items for emacs (#1481, @mndrix)
    • emacs: Make the prefix argument to merlin-locate optional, both for consistency with Emacs convention and for backwards compatibility. (#1476, @antalsz)
    • emacs: fix duplicated prefix path in imenu entries (#1495, @bcc32)

OCaml-LSP 1.12.0

ocaml-lsp platform editors
See full changelog

Features

  • Fix cancellation mechanism for all requests (#707)

  • Allow cancellation of formatting requests (#707)

  • Add --fallback-read-dot-merlin to the LSP Server (#705). If ocamllsp is started with this new flag, it will fall back to looking for Merlin configuration in .merlin files rather than calling dune ocaml-merlin. (#705)

  • Support folding more ranges (#692)

OCaml-LSP 1.11.5

ocaml-lsp platform editors
See full changelog

  • Fix process termination. Once the lsp server is stepped, the process will gracefully terminate (#697, fixes #694)

  • Forward stderr from dune's merlin configuration to the lsp server's stderr (#697)

OCaml-LSP 1.11.0

ocaml-lsp platform editors

On behalf of the ocamllsp team, I’m excited to announce the availability of version 1.11.0. This release is an important milestone for the project because it introduces integration with our favorite build system. When you run dune in watch mode, you will now be able to see build errors in the diagnostics panel of your editor. It’s all rather experimental for now, so your feedback and bug reports are appreciated.

As usual, the full change log is below.

Happy hacking.

See full changelog

Features

  • Add support for dune in watch mode. The lsp server will now display build errors in the diagnostics and offer promotion code actions.

  • Re-introduce ocamlformat-rpc (#599, fixes #495)

Fixes

  • Fix workspace symbols that could have a wrong path in some cases (#675)

Merlin 4.5

merlin platform editors
See full changelog
  • merlin binary
    • don't reset the environment when running merlin in single mode so that the parent environment is forwarded the the child processes (#1425)
    • filter dups in source paths (#1218)
    • improve load path performance (#1323)
    • fix handlink of ppx's under Windows (#1413)
    • locate: look for original source files before looking for preprocessed files (#1219 by @ddickstein, fixes #894)
    • handle = syntax in compiler flags (#1409)
    • expose all destruct exceptions in the api (#1437)
    • fix superfluous break in error reporting (#1432)
    • recognise binding operators in locate and occurrences (#1398, @mattiase)
    • remove dependency on Result (#1441, @kit-ty-kate)
    • use the new "shapes" generated by the compiler to perform precise jump-to-definition (#1431)
  • editor modes
    • fix an issue in Neovim where the current line jumps to the top of the window on repeated calls to MerlinTypeOf (#1433 by @ddickstein, fixes #1221)
    • add module, module type, and class imenu items for emacs (#1244, @ivg)
    • add prefix argument to force or prevent opening in a new buffer in locate command (#1426, @panglesd)
    • add type-on-hover functionality for vim (#1439, @nilsbecker)
    • add a dedicated buffer *merlin-errors* containing the last viewed error (#1414, @panglesd)
  • test suite
    • make merlin-wrapper create a default .merlin file only when there is no dune-project to let tests use dune ocaml-merlin reader. (#1425)
    • cover locate calls on module aliases with and without dune
    • Add a test expliciting the interaction between locate and Dune's generated source files (#1444)
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