c3.nvim

Support for C3 in Neovim.

• LSP auto-installation and setup (tonis2/lsp).
• Tree-Sitter grammar and highlights (tree-sitter-c3).
• Code formatting via :C3Format or :Format (c3fmt).
• Diagnostic info via :C3Info.
• :C3Update [tool]: Updates dependencies (lsp, formatter, or both).

Just install the plugin and open a .c3 file. Everything is hopefully managed automatically.

Dependencies

• c3c (C3 compiler) must be in your PATH.
• git and a C compiler (gcc, clang, etc.) to build Tree-Sitter.
• curl and tar (or unzip) to download LSP and formatter.

Installation

lazy.nvim

{
  "ManuLinares/nvim-c3",
  build = function() require("c3").update() end, -- (Optional) Auto-update binaries
  config = true,
}

vim-plug

Plug 'ManuLinares/nvim-c3'

packer.nvim

use {
  'ManuLinares/nvim-c3',
  config = function()
    require("c3").setup()
  end
}

Vanilla Neovim (Native Packages)

If you do not use a package manager, install the plugin using Neovim's built-in package system by cloning it into your startup packpath:

git clone https://github.com/ManuLinares/nvim-c3 ~/.local/share/nvim/site/pack/plugins/start/nvim-c3

Then, initialize the plugin by adding these lines to your init.lua:

require("c3").setup()

-- Enable inline diagnostic error messages (disabled by default in stock Neovim)
vim.diagnostic.config({ virtual_text = true })

Quick Install Guide (Arch Linux)

# 1. Install dependencies
sudo pacman -S neovim git curl unzip tar base-devel c3c

# 2. Setup LazyVim
git clone https://github.com/LazyVim/starter ~/.config/nvim

# 3. Add this plugin
cat << 'EOF' > ~/.config/nvim/lua/plugins/c3.lua
return {
  { "ManuLinares/nvim-c3", config = true }
}
EOF

Quick Install Guide (Ubuntu / Debian)

# 1. Install dependencies
sudo apt update && sudo apt install -y neovim git curl unzip tar build-essential

# 2. Install c3c (Download manually)
mkdir -p ~/.local
curl -sL https://github.com/c3lang/c3c/releases/latest/download/c3-linux.tar.gz | tar -xz -C ~/.local
echo 'export PATH="$HOME/.local/c3:$PATH"' >> ~/.bashrc
source ~/.bashrc

# 3. Setup LazyVim
git clone https://github.com/LazyVim/starter ~/.config/nvim

# 4. Add this plugin
cat << 'EOF' > ~/.config/nvim/lua/plugins/c3.lua
return {
  { "ManuLinares/nvim-c3", config = true }
}
EOF

Vim (without Neovim)

If you use plain Vim (not Neovim), copy the plugin directory into your Vim runtime path:

cp -r . ~/.vim

You'll get filetype detection and syntax highlighting for .c3, .c3i, and .c3t files out of the box.

Note: LSP, Tree-Sitter highlighting, formatting, and all :C3* commands require Neovim and are not available in plain Vim.

Configuration

Settings are optional. Default values:

require("c3").setup({
  lsp = {
    enable = true, -- Set to false to disable LSP
    cmd = "c3lsp",
    version = "latest", -- (2)
    compiler_path = nil, -- Custom path to c3c binary (3)
    stdlib_path = nil, -- Custom path to C3 standard library (3)
  },
  formatter = {
    enable = true, -- Set to false to disable formatter
    cmd = "c3fmt",
    format_on_save = false,
    config_file = nil, -- Path to .c3fmt file (1)
    version = "latest", -- (2)
  },
  highlighting = {
    enable_treesitter = true,
  }
})

• (1): Path to a .c3fmt configuration file. If a relative path is used, it is resolved from Neovim's current working directory (see :pwd). See c3fmt configuration for more details.
• (2): Minimum version or tag name from GitHub (e.g., "v0.1.4"). Defaults to "latest".
• (3): Paths are automatically resolved by locating c3c on your system path and querying the standard library path via c3c compile - --build-env. Provide absolute paths here only to explicitly override the automatic detection.