lsp-bridge

Lsp-bridge's goal is to become the fastest LSP client in Emacs.

Lsp-bridge uses python's threading technology to build caches that bridge Emacs and LSP server. Lsp-bridge will provide smooth completion experience without compromise to slow down emacs' performance.

Installation

Install Python dependencies: python-epc
Install Elisp dependencies:

corfu, orderless (for corfu users)
company-mode, company-box (for company users)
all-the-icons (need execute command all-the-icons-install-fonts to install all-the-icons fonts)
posframe
markdown-mode
yasnippet

Clone or download this repository (path of the folder is the <path-to-lsp-bridge> used below).
Add following code in your ~/.emacs:

Corfu user.

(add-to-list 'load-path "<path-to-lsp-bridge>")

(require 'yasnippet)
(require 'lsp-bridge)
(require 'lsp-bridge-icon)        ;; show icons for completion items, optional
(require 'lsp-bridge-jdtls)       ;; provide Java third-party library jump and -data directory support, optional
(yas-global-mode 1)

(setq lsp-bridge-completion-provider 'corfu)
(require 'corfu)
(require 'corfu-info)
(require 'corfu-history)
(require 'lsp-bridge-orderless)   ;; make lsp-bridge support fuzzy match, optional
(corfu-history-mode t)
(global-lsp-bridge-mode)
(when (> (frame-pixel-width) 3000) (custom-set-faces '(corfu-default ((t (:height 1.3))))))  ;; adjust default font height when running in HiDPI screen.

Company user

(add-to-list 'load-path "<path-to-lsp-bridge>")

(require 'yasnippet)
(require 'lsp-bridge)
(require 'lsp-bridge-icon)        ;; show icons for completion items, optional
(require 'lsp-bridge-jdtls)       ;; provide Java third-party library jump and -data directory support, optional
(yas-global-mode 1)

(setq lsp-bridge-completion-provider 'company)
(require 'company)
(require 'company-box)
(global-lsp-bridge-mode)

Commands

lsp-bridge-find-def: jump to the definition
lsp-bridge-find-def-other-window: jump to the definition in other-window
lsp-bridge-find-impl: jump to the implementation
lsp-bridge-find-impl-other-window: jump to the implementation in other-window
lsp-bridge-return-from-def: return to the location before calling lsp-bridge-find-def
lsp-bridge-find-references: traverse across code references (forked from color-rg.el)
lsp-bridge-lookup-documentation: lookup documentation of symbol under the cursor
lsp-bridge-popup-documentation-scroll-up: scroll up popup document.
lsp-bridge-popup-documentation-scroll-down: scroll down popup document.
lsp-bridge-rename: rename symbol under the cursor
lsp-bridge-jump-to-next-diagnostic: Jump to the next diagnostic position
lsp-bridge-jump-to-prev-diagnostic: Jump to the previous diagnostic position
lsp-bridge-show-signature-help-in-minibuffer: show signature help in minibuffer manually (move cursor to parameters area will show signature help automatically)
lsp-bridge-insert-common-prefix: insert common prefix of candidates
lsp-bridge-restart-process: restart lsp-bridge process (only used for development)

Customize lsp-bridge keymap

customize keymap for lsp-bridge commands.

eg:

(defvar lsp-bridge-mode-map
    (let ((keymap (make-sparse-keymap)))
    (define-key keymap (kbd "C-j") 'lsp-bridge-popup-documentation-scroll-up)
    (define-key keymap (kbd "C-k") 'lsp-bridge-popup-documentation-scroll-down)
    keymap))

Customize language server configuration

The default configuration of for each language server is stored at lsp-bridge/langserver.

Anyway you can customize server configuration with the following priority:

lsp-bridge-get-lang-server-by-project: write your own function to get server configuration based on project-path and file-path, this function is nil by default
lsp-bridge-lang-server-extension-list: load server configuration based on file extension, such as, we launch volar server instead javascript server when open *.vue file
lsp-bridge-lang-server-mode-list: load server configuration based on major-mode

Add support for new language?

Create configuration file under lsp-bridge/langserver, such as pyright.json for pyright (windows user please uses pyright_windows.json, macOS user please uses pyright_darwin.json).
Add (mode . server_name) in lsp-bridge-lang-server-list, such as (python-mode . "pyright")
Add new mode-hook to lsp-bridge-default-mode-hooks

Welcome to send PR to help us improve support for LSP servers, thanks for your contribution!

Supported language servers

Index	LSP Server	Language	Note
1	clangd	c, c++
2	pyright	python	`pip install pyright`
3	solargraph	ruby
4	rust-analyzer	rust
5	elixirLS	elixir	please ensure that the `elixir-ls` release directory is in your system PATH at first
6	gopls	go	make sure gopls in PATH, please do `ln -s ~/go/bin/gopls ~/.local/bin`
7	hls	haskell
8	dart-analysis-server	dart
9	metals	scala
10	typescript	typescript, javascript
11	ocamllsp	ocaml
12	erlang-ls	erlang
13	texlab	latex
14	eclipse.jdt.ls	java	please ensure that `org.eclipse.jdt.ls.product/target/repository/bin` is in your system PATH at first
15	clojure-lsp	clojure
16	bash-language-server	bash
17	volar	vue
18	sumneko	lua	please ensure `bin` under sumneko installation is in your system PATH at first
19	wxml-language-server	wxml
20	vscode-html-language-server	html
21	vscode-css-language-server	css
22	elm-language-server	elm

TODO:

Show signature help with eldoc
Code action
Inline Value
JavaSctipt different code blocks use different language servers
Support completionItem/resolve to implement auto-import for volar
Cache candidate document at Python side, only fetch document information when switch candidate.

Features that won't be supported

The goal of lsp-bridge is to become the fastest LSP client in Emacs, not a complete implementation of LSP protocol.

Emacs can do better for the following tasks, we will not reinvent the wheel in lsp-bridge:

Code formatting: each LSP server has its own formatting specification, we can gain finer control using Emacs' builtin formatting tool.
Syntax highlighting: Tree-sitter is a wonderful incremental parsing library for syntax highlighting.
Xref: Xref's mechanism is simultaneously. lsp-bridge is completely asynchronous, recommended to use wrap function to uniformly key

Join development

The following is the framework of lsp-bridge:

The following is the directory structure of the lsp-bridge project:

File	Explanation
lsp-bridge.el	Elisp main logic part that provides custom options and elisp functions for python sub-process calls like code jumping, renaming, etc.
lsp-bridge-epc.el	Communicating with lsp-bridge python sub-process, which mainly implements elisp IPC to connect to python EPC for data serialization, sending, receiving, and deserialization
lsp-bridge-ref.el	Framework of code referencing, providing references viewing, batch renames, regex filtering of reference results, etc. The core code is forked from color-rg.el
lsp-bridge-orderless.el	Fuzzy search for completion items, i.e. for long candidate you do not need to type the word in correct order to get the correct item
lsp-bridge-icon.el	Rendering the completion menu icons, which is used to distinguish different types of completion options
lsp-bridge.py	Python main logic part that provides event loop, message scheduling and status management
core/fileaction.py	Tracking the status of each file, processing LSP response messages, calling Emacs elisp function
core/lspserver.py	LSP message processing module, mainly to analyze, send and receive LSP messages, and ensure that the sequence of LSP requests conforms with the LSP protocol specification
core/utils.py	Utility functions of convenience for each module call
core/hanlder/	The implementation of sending and receiving LSP message, where init.py is a base class
langserver	The configurations of the LSP servers, each server corresponding to a JSON file that defines the name of the server, language ID, starting command, options, etc.

Please read LSP Specification and The Design of lsp-bridge first.

Then turn on option lsp-bridge-enable-log and happy hacking! ;)

Report bug

Please use emacs -q and load a minimal setup with only lsp-bridge to verify that the bug is reproducible. If emacs -q works fine, probably something is wrong with your Emacs config.

If the problem still exists, please report it here with *lsp-bridge* buffer content, it contains many clues that can help us locate the problem faster.

If you get a segfault error, please use the following way to collect crash information:

Install gdb and turn on option lsp-bridge-enable-debug
Use the command lsp-bridge-stop-process to stop the current process
Restart lsp-bridge, send issue with *lsp-bridge* buffer content when next crash

wsw0108 / lsp-bridge