package ocaml-lsp-server

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1.10.2 (unreleased)


  • Catch merlin desturct exceptions (#626)

  • Fix broken debouncing (#627)



  • Fix executing ppx executables



  • Add better support for code folding: more folds and more precise folds


  • Fix infer interface code action crash when implementation source does not exist (#597)

  • Improve error message when the reason plugin for merlin is absent (#608)

  • Fix chdir races when running ppx (#550)

  • More accurate completion kinds. New completion kinds for variants and fields. Removed inaccurate completion kinds for constructors and types. (#510)

  • Fix handling request cancellation (#616)



  • Disable functionality reliant on ocamlformat-rpc for now (#555)

  • 4.13 compatiblity

1.9.0 (11/21/2021)


  • Ppx processes are now executed correctly (#513)

Breaking Change

  • ocamllsp drops support for .merlin files, and as a consequence no longer depends on dot-merlin-reader. (#523)


  • New code action to automatically remove values, types, opens (#502)

1.8.3 (09/26/2021)

  • Fix debouncing of document updates. It was essentially completely broken in all but the most trivial cases. (#509 fixes #504)

  • Fix completion when passing named and functional arguments (#512)

1.8.2 (09/14/2021)

  • Disable experimental dune support. It was accidentally left enabled.

1.8.1 (09/12/2021)

  • Update to latest merlin.

1.8.0 (08/19/2021)


  • Handle workspace change notifications. Previously, the server would only use the set of workspaces given at startup to search for workspace symbols. After this change, workspace folders that are added later will also be considered. (#498)


  • Add a new code action Add missing rec keyword, which is available when adding a rec keyword can fix Unbound value ... error, e.g.,

    let fact n = if n = 0 then 1 else n * fact (n - 1)
                                       (* ^^^^ Unbound value fact *)

    Adding rec to the definition of fact will fix the problem. The new code action offers adding rec.

  • Use ocamlformat to properly format type snippets. This feature requires the ocamlformat-rpc opam package to be installed. (#386)

  • Add completion support for polymorphic variants, when it is possible to pin down the precise type. Examples (<|> stands for the cursor) when completion will work (#473)

    Function application:

    let foo (a: [`Alpha | `Beta]) = ()
    foo `A<|>

    Type explicitly shown:

    let a : [`Alpha | `Beta] = `B<|>

    Note: this is actually a bug fix, since we were ignoring the backtick when constructing the prefix for completion.

  • Parse merlin errors (best effort) into a more structured form. This allows reporting all locations as "related information" (#475)

  • Add support for Merlin Construct command as completion suggestions, i.e., show complex expressions that could complete the typed hole. (#472)

  • Add a code action Construct an expression that is shown when the cursor is at the end of the typed hole, i.e., _|, where | is the cursor. The code action simply triggers the client (currently only VS Code is supported) to show completion suggestions. (#472)

  • Change the formatting-on-save error notification to a warning notification (#472)

  • Code action to qualify ("put module name in identifiers") and unqualify ("remove module name from identifiers") module names in identifiers (#399)

    Starting from:

    open Unix
    let times = Unix.times ()
    let f x = x.Unix.tms_stime, x.Unix.tms_utime

    Calling "remove module name from identifiers" with the cursor on the open statement will produce:

    open Unix
    let times = times ()
    let f x = x.tms_stime, x.tms_utime

    Calling "put module name in identifiers" will restore:

    open Unix
    let times = Unix.times ()
    let f x = x.Unix.tms_stime, x.Unix.tms_utime


  • Do not show "random" documentation on hover

  • Correctly rename a variable used as a named/optional argument (#478)

  • When reporting an error at the beginning of the file, use the first line not the second (#489)

1.7.0 (07/28/2021)


  • Add sub-errors as "related" information in diagnostics (#457)

  • Add support for navigating to a symbol inside a workspace (#398)

  • Show typed holes as errors

    Merlin has a concept of "typed holes" that are syntactically represented as _. Files that incorporate typed holes are not considered valid OCaml, but Merlin and OCaml-LSP support them. One example when such typed holes can occur is when on "destructs" a value, e.g., destructing (Some 1) will generate code match Some 1 with Some _ -> _ | None -> _. While the first underscore is a valid "match-all"/wildcard pattern, the rest of underscores are typed holes.

1.6.1 (05/17/2020)


  • Switch verbosity from 1 to 0. This is the same default that merlin uses. The old value for verbosity (#433)

  • Get fresh diagnostics (warning and error messages) on a file save (#438)

    Note: If you want the fresh diagnostics to take into account changes in other files, you likely need to rebuild your project. An easy way to get automatic rebuilds is to run dune in a watching mode, e.g.,[dune build --watch].

1.6.0 (04/30/2020)


  • Code action to annotate a value with its type (#397)


  • Fix interface/implementation switching on Windows (#427)

  • Correctly parse project paths with spaces and other special characters that must be escaped.

  • Print types with -short-paths even if the project wasn't built yet

1.5.0 (03/18/2020)

  • Support 4.12 and drop support for all earlier versions

  • Update to the latest version of merlin

1.4.1 (03/16/2020)


  • Backport fixes from merlin (#382, #383)

  • Encode request & notification params in a list. This is required by the spec. (#351)

1.4.0 (12/17/2020)


  • Support cancellation notifications when possible. (#323)

  • Implement signature help request for functions (#324)

  • Server LSP requests & notifications concurrently. Requests that require merlin are still serialized. (#330)

1.3.0 (11/23/2020)


  • Code action to insert inferred module interface (#308)

  • Filter keywords by context (#307)

1.2.0 (11/16/2020)


  • Add keyword completion

  • Add go to declaration functionality to jump to a value's specification in a .mli file (#294)


  • #245: correctly use mutexes on OpenBSD (#264)

  • #268: Do not use vendored libraries when building the lsp package (#260)

  • #271: Clear diagnostics when files are closed

  • Disable non-prefix completion. There's no reliably way to trigger it and it can be slow.

1.1.0 (10/14/2020)


  • Implement a command to switch between module interfaces and implementations (#254)


  • Do not crash on invalid positions (#248)

  • add missing record fields to list of completions (#253)

  • do not offer destruct as a code action in interface files (#255)

1.0.0 (08/28/2020)

  • Initial Release


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