https://github.com/bryphe/merlin-language-server

Minimal cross-platform LSP wrapper for merlin
https://github.com/bryphe/merlin-language-server

lsp lsp-server merlin merlin-language-server ocaml reason

Last synced: 7 months ago
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Minimal cross-platform LSP wrapper for merlin

• Host: GitHub
• URL: https://github.com/bryphe/merlin-language-server
• Owner: bryphe
• License: mit
• Created: 2018-12-08T16:02:08.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2019-03-03T21:26:20.000Z (over 6 years ago)
• Last Synced: 2025-03-18T21:16:01.683Z (7 months ago)
• Topics: lsp, lsp-server, merlin, merlin-language-server, ocaml, reason
• Language: OCaml
• Homepage:
• Size: 133 KB
• Stars: 28
• Watchers: 2
• Forks: 0
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
[![Build Status](https://bryphe.visualstudio.com/merlin-language-server/_apis/build/status/bryphe.merlin-language-server?branchName=master)](https://bryphe.visualstudio.com/merlin-language-server/_build/latest?definitionId=16?branchName=master)

# merlin-language-server

### Simple LSP protocol wrapper for [`merlin`](https://github.com/ocaml/merlin), written in [reason](https://reasonml.github.io/)

:warning: Alpha quality

### Overview

`merlin-language-server` is a thin wrapper over the excellent [`merlin`](https://github.com/ocaml/merlin) tooling - implementing the LSP protocol on-top of [`merlin`'s protocol](https://github.com/ocaml/merlin/blob/master/doc/dev/PROTOCOL.md). 

As with `ocaml-language-server`, this is not intended as a replacement for any existing Reason / OCaml tooling, but to make it more accessible across editors.

### Why?

There are already two excellent language server implementations - [`reason-language-server`](https://github.com/jaredly/reason-language-server) and [`ocaml-language-server`](https://github.com/freebroccolo/ocaml-language-server) - why another one?

The current language-server landspace could be summarized with this table:

| __Language Server__ | Uses `merlin` | Implemented in `reason` | Supports Windows |

| --- | --- | --- | --- |

| `ocaml-language-server` | :white_check_mark: | :x: | :x: (1) |

| `reason-language-server` | :x: | :white_check_mark: | :x: (2) |

| `merlin-language-server` | :white_check_mark: | :white_check_mark: | :white_check_mark: |

> __NOTE (1):__ I believe `ocaml-language-server` may support Windows, but I was not able to get it working.

> __NOTE (2):__ `reason-language-server` mentions Windows support as a goal, but again, it did not work for me. I contributed several fixes towards this (PRs [#36](https://github.com/jaredly/reason-language-server/pull/36), [#130](https://github.com/jaredly/reason-language-server/pull/130), [#199](https://github.com/jaredly/reason-language-server/pull/199)), but there is still significant investment required to get support on parity with `merlin` on Windows.

The primary issue for me being that there was not a language server implementation that worked well for me on Windows. It turns out that `merlin` works great on Windows - so having a native-reason LSP implementation that uses `merlin` is a natural choice. 

In the future, perhaps we could integrate this more fully into `merlin` at some point, or incorporate `merlin` as a library that we call directly.

### Building

#### Prerequisites

- You will need [`esy`](https://esy.sh) to build - `npm install -g esy`

- For running tests, you will need `node`.

#### Build

- `git clone https://github.com/bryphe/merlin-language-server`

- `esy install`

- `esy build`

#### Tests

- Unit tests: `esy x TestRunner.exe`

- E2E tests: 

    - `cd test-e2e`

    - `npm install`

    - `npm test`

### Roadmap

- Distribution

    - [ ] First-class Oni integration

    - [ ] VSCode Plugin

    - [ ] NPM package with pre-built binaries

- Features

    - Text synchronization

        - [x] `textDocument/didOpen`

        - [x] `textDocument/didChange`

        - [x] Full document sync

        - [ ] Incremental document sync

    - Language Features

        - [x] `completion`

        - [x] `hover`

        - [ ] `definition`

        - [ ] `implementation`

        - [ ] `references`

        - [ ] `signatureHelp`

        - [ ] `codeAction`?

        - [ ] `codeLens`

        - [ ] `formatting`

        - [ ] `rangeFormatting`

        - [ ] `onTypeFormatting`

### Contributions

Contributions & PRs are welcome! Please ensure that test coverage is added for any new functionality - either in the form of unit tests or E2E tests.

### License

[MIT License](LICENSE)

Copyright 2018 Bryan Phelps