mui-lsp

LSP (Language Server Protocol) plugin for Mui editor.

Features

• Hover: Show documentation for symbol under cursor (K or \h or :LspHover)
• Go to Definition: Jump to symbol definition (\d or :LspDefinition)
• Find References: Show all references to symbol (\r or :LspReferences)
• Completion: Get code completion suggestions (\c or :LspCompletion)
• Diagnostics: Display errors and warnings from LSP server (:LspDiagnostics)

Supported Language Servers

Pre-configured servers for Ruby:

• Solargraph - Full-featured Ruby language server
• ruby-lsp - Shopify's Ruby language server
• Kanayago - Realtime Ruby Syntax Check server
• RuboCop (LSP mode) - Ruby linter with LSP support

Custom servers can be configured for other languages.

Installation

Add to your .muirc:

# ~/.muirc
Mui.use "mui-lsp"

Or if installing from a local path:

# ~/.muirc
Mui.use "mui-lsp", path: "/path/to/mui-lsp"

Configuration (Required)

Important: mui-lsp does not auto-detect LSP servers. You must explicitly configure which server(s) to use in your .muirc.

Quick Setup

Use the Mui.lsp DSL block to configure servers:

# ~/.muirc
Mui.use "mui-lsp"

Mui.lsp do
  use :solargraph
end

Available pre-configured servers:

• :solargraph - Solargraph (full-featured Ruby LSP)
• :ruby_lsp - ruby-lsp (Shopify's Ruby LSP)
• :rubocop - RuboCop in LSP mode
• :kanayago - Kanayago (Japanese Ruby LSP)

Custom Server Configuration

For other languages or custom setups, use the server method:

# ~/.muirc
Mui.use "mui-lsp"

Mui.lsp do
  # TypeScript/JavaScript
  server name: "typescript",
         command: "typescript-language-server --stdio",
         language_ids: ["typescript", "javascript"],
         file_patterns: ["**/*.ts", "**/*.tsx", "**/*.js", "**/*.jsx"]

  # Python (pyright)
  server name: "pyright",
         command: "pyright-langserver --stdio",
         language_ids: ["python"],
         file_patterns: ["**/*.py"]
end

Multiple Servers

You can enable multiple servers for different file types:

# ~/.muirc
Mui.use "mui-lsp"

Mui.lsp do
  # Ruby
  use :solargraph

  # TypeScript/JavaScript
  server name: "typescript",
         command: "typescript-language-server --stdio",
         language_ids: ["typescript", "javascript"],
         file_patterns: ["**/*.ts", "**/*.tsx", "**/*.js", "**/*.jsx"]
end

Usage

Starting LSP Server

LSP servers are automatically started when you open a file that matches their configured file patterns.

To manually start a server:

:LspStart solargraph
:LspStart ruby-lsp
:LspStart rubocop

Commands

Command	Description
:LspStart <name>	Start a specific LSP server
:LspStop [name]	Stop a server (all if no name given)
:LspStatus	Show running and registered servers
:LspHover	Show hover information
:LspDefinition	Go to definition
:LspReferences	Find all references
:LspCompletion	Show completion menu
:LspDiagnostics	Show diagnostics for current file
:LspDiagnosticShow	Show diagnostic at cursor in floating window
:LspLog	Show LSP server logs in a buffer
:LspDebug	Show debug information
:LspOpen	Manually notify LSP server about current file

Keymaps

Leader key is \ (backslash).

Key	Mode	Description
K	Normal	Show hover information (in floating window)
\h	Normal	Show hover information (alternative)
\d	Normal	Go to definition
\r	Normal	Find references
\c	Normal	Show completion
\e	Normal	Show diagnostic at cursor (in floating window)
Esc	Normal	Cancel leader pending state / Close floating window

Architecture

mui-lsp/
  lib/mui/lsp/
    protocol/          # LSP protocol definitions
      position.rb      # Position (line, character)
      range.rb         # Range (start, end positions)
      location.rb      # Location (URI, range)
      diagnostic.rb    # Diagnostic (error/warning/info)
    handlers/          # Response handlers
      base.rb          # Base handler class
      hover.rb         # Hover response handler
      definition.rb    # Definition response handler
      references.rb    # References response handler
      diagnostics.rb   # Diagnostics notification handler
      completion.rb    # Completion response handler
    json_rpc_io.rb     # JSON-RPC 2.0 over stdio
    request_manager.rb # Request ID and callback management
    server_config.rb   # Server configuration presets
    client.rb          # LSP client (manages server process)
    text_document_sync.rb # Document synchronization
    manager.rb         # Multi-server manager
    plugin.rb          # Mui plugin integration

Development

cd mui-lsp
bundle install
bundle exec rake test
bundle exec rubocop

License

MIT License