Texpresso LSP

A simple Language Server Protocol implementation using the vscode-languageserver library with TypeScript support.

Currently implemented features

• Live preview
• Inverse search
• Forward search following cursor

Purpose

This is an experimental implementation of a Language Server Protocol (LSP) server wrapping around TeXpresso executable. See let-def/texpresso#36.

This is a "cheap" nodeJS implementation for quick and easy testing. However this could also still be fit for purpose in its final form since it is a pretty thin interface where the JavaScript is not responsible for much and what it is responsible for (JSON parsing and manipulation) is stuff that is well suited to (in terms of performance and ergonomics).

Setup

1. Install TeXpresso, more specifically it needs to be built from this branch: https://github.com/lnay/texpresso/tree/utf-8.
2. Make the texpresso executable available in your PATH, or make sure to specify its path in step 4.
3. Install the language server, either from this repo or just:

   npm install -g texpresso-lsp

4. Set up the editor to run the language server with texpresso-lsp --stdio with the following initialization options:

{
  "root_tex": "path/to/root.tex", // can be relative to the workspace root
  // ^ defaults to "main.tex" if not specified
  "texpresso_path": "path/to/texpresso", // can be missed if texpresso is in PATH
  // command to open the editor at a given file and line number:
  "inverse_search": {
    "command": "zed",
    "arguments": ["%f:%l"],
    // %f and %l are placeholders for the file path and line number respectively
  }
}

For zed, just install the following extension instead of step 4 (and maybe 3 soon): https://github.com/lnay/zed-texpresso

Workspace Settings

The language server supports the following workspace settings that can be configured in your editor:

{
  "texpresso.preview_follow_cursor": true // default: true
  // Controls whether the preview window follows the cursor position
}

These settings can be changed at runtime and the language server will respond to configuration changes immediately.

Generic npm package instructions

1. Install dependencies:

npm install

2. Build the TypeScript code:

npm run build

3. Run the server:

npm start

For development:

npm run dev