My Emacs Configuration

A comprehensive Emacs configuration focused on Python, C++, and Go development with modern IDE-like features.

Quick Start

git clone https://github.com/slgao/emacs.d.git ~/.emacs.d

Start Emacs and the configuration will automatically install required packages on first run.

Then complete the one-time manual setup steps described below for each language/tool you use.

Features

Core IDE Features

• Auto-completion: Company mode with intelligent backends
• Syntax checking: Flycheck with language-specific linters
• Project navigation: Ivy/Counsel/Swiper for fuzzy searching
• Version control: Magit integration for Git
• Window management: Ace-window for quick window switching
• File management: Enhanced Dired with dired+
• Multiple cursors: Edit multiple locations simultaneously

Python Development

• LSP mode: Full IDE experience via pylsp (goto-definition, completion, diagnostics)
• Virtual environment support: pyvenv for environment switching
• Code formatting: py-autopep8 with customizable line length (100 chars)
• Documentation: Sphinx-doc mode for docstring generation
• Linting: Flake8 integration via Flycheck

C/C++ Development

• Irony mode: Clang-based completion and syntax checking
• Company-irony: Intelligent auto-completion
• CMake support: CMake mode for build configuration
• Code formatting: Clang-format integration
• Flycheck-irony: Real-time syntax checking
• Helm-gtags: Code navigation and symbol lookup

AI Assistance

• GitHub Copilot: Inline completions in Python, C/C++, shell, YAML, and Terraform
  • Accept completion: C-M-<return>
  • Next/previous suggestion: C-M-<next> / C-M-<prior>
  • Accept by word: C-M-<right>
  • Accept by line: C-M-<down>
  • Clear overlay: C-c C-c

UI/UX Enhancements

• Themes: Multiple themes available (Gruvbox default, Monokai, Zenburn, etc.)
• Smart defaults: Sensible configuration out of the box
• Custom keybindings: Optimized workflow shortcuts
• Visual indicators: Line highlighting, parentheses matching
• Time display: Date and time in mode line
• Recent files: Quick access to recently opened files

Additional Tools

• Org mode: Enhanced with org-bullets and agenda integration
• Terraform: terraform-mode with LSP support
• Web development: Web-mode and Emmet for HTML/CSS
• Git integration: Magit for version control
• Snippet expansion: YASnippet support
• Kill ring browser: Enhanced clipboard management
• Undo tree: Visual undo/redo system
• Neotree: File tree sidebar with icons

Configuration Structure

~/.emacs.d/
├── early-init.el              # Prevents package.el auto-init (loaded before init.el)
├── init.el                    # Entry point, loads org-babel config
├── shulins_emacs_config.org   # Main configuration in org-babel format
├── lisp/                      # Modular configuration files
│   ├── init-packages.el       # Package management and setup
│   ├── init-ui.el            # UI and theme configuration
│   ├── init-better-defaults.el # Sensible defaults
│   ├── init-keybindings.el   # Custom key bindings
│   ├── init-org.el           # Org mode configuration
│   ├── init-utils.org        # Utility functions
│   └── custom.el             # Emacs custom variables
├── site-lisp/                # Third-party packages
│   ├── nadvice_.el           # Extended advice system
│   ├── org-bullets.el        # Org mode visual enhancements
│   ├── dired+.el            # Enhanced directory editor
│   └── move-lines.el         # Line manipulation utilities
└── snippets/                 # YASnippet templates

Key Bindings

Global Shortcuts

• F2 - Open init file
• C-x C-r - Recent files
• C-s - Swiper search
• M-x - Counsel M-x (enhanced command palette)
• C-x C-f - Counsel find file
• C-x o - Ace window (quick window switching)
• C-c a - Org agenda
• M-/ - Hippie expand (smart completion)
• C-c f - Open current directory in OS file manager
• C-c r - Revert (reload) current buffer

Development

• M-. - Go to definition (via lsp-mode / xref)
• M-, - Go back after jump
• M-s i - Browse symbols in current file (counsel-imenu, LSP-enriched)
• M-s I - Search symbols across entire project (lsp-ivy workspace)
• C-h C-f - Find function definition
• C-h C-v - Find variable definition
• C-h C-k - Find function on key
• C-M-\ - Indent region or buffer
• C-: - Avy goto word (quick navigation)

Manual Setup

These steps must be completed once per machine after cloning.

Python (lsp-mode via pylsp)

Linux / macOS

pip3 install python-lsp-server

Windows

pip install python-lsp-server

No further Emacs configuration needed — lsp-mode auto-starts when you open a Python file and M-. navigates to definitions.

To switch virtual environments at runtime use M-x pyvenv-activate.

GitHub Copilot

Prerequisites — install Node.js and npm

Platform	Command
Linux (Debian/Ubuntu)	sudo apt-get install nodejs npm
macOS	brew install node
Windows	Download from https://nodejs.org

Install the Copilot language server (once per machine)

Inside Emacs:

M-x copilot-install-server

Authenticate with GitHub (once per machine)

Inside Emacs:

M-x copilot-login

Follow the device-auth prompt: copy the code shown in the minibuffer, open the URL in a browser, and paste the code. Copilot will activate automatically after login.

C/C++ (irony + clang)

# Linux
sudo apt-get install clang cmake

# macOS
brew install llvm cmake

Inside Emacs, run once per project:

M-x irony-install-server

Terraform (lsp-mode)

Install the Terraform LSP server:

# Download terraform-ls from https://github.com/hashicorp/terraform-ls/releases
# and place the binary somewhere on your PATH

Go (go-mode + gopls)

1. Install Go from https://go.dev/dl/
2. Install the Go language server:

   go install golang.org/x/tools/gopls@latest

No further Emacs configuration needed — lsp-mode auto-starts, gofmt/goimports runs on save, and Copilot is active in go-mode buffers.

Package Management

Packages are managed via MELPA/ELPA (package.el). On first Emacs startup, all packages listed in shulin/packages in lisp/init-packages.el are installed automatically.

Adding New Packages

1. Add the package name to shulin/packages in lisp/init-packages.el
2. Add configuration in the same file or create a new module
3. Restart Emacs

Changing Themes

Edit lisp/init-ui.el and change the load-theme line:

(load-theme 'your-preferred-theme t)

Custom Keybindings

Add new bindings in lisp/init-keybindings.el.

Troubleshooting

M-. still shows "visit tags table" in Python

LSP mode failed to start. Check:

1. pylsp is installed and on PATH: which pylsp
2. Emacs can see it: M-x eval-expression → (executable-find "pylsp")
3. View LSP status: M-x lsp-describe-session

Copilot "Not authenticated"

Run M-x copilot-login and complete the GitHub device-auth flow.

Copilot "language server not installed"

Run M-x copilot-install-server (requires npm).

Python Issues

• Switch virtual environment: M-x pyvenv-activate
• Check LSP server status: M-x lsp-describe-session

C++ Issues

• Ensure clang is installed and accessible
• Provide compile_commands.json (via CMake with CMAKE_EXPORT_COMPILE_COMMANDS=ON)

Requirements

• Emacs 26+
• Git
• Python 3.6+ with pip
• Node.js 18+ and npm (for Copilot)
• Clang (for C++ development)
• CMake (for C++ project management)
• Go 1.18+ with gopls (for Go development)

License

This configuration is provided as-is for educational and personal use.