Editor Setup

Configure your editor for the best FastC development experience.

VS Code

Language Server (Recommended)

FastC includes a Language Server Protocol (LSP) implementation for rich editor support.

Building the LSP

cd fastc
cargo build --release -p fastc-lsp

The binary is at target/release/fastc-lsp.

VS Code Configuration

Create or edit .vscode/settings.json in your workspace:

{
    "fastc.serverPath": "/path/to/fastc/target/release/fastc-lsp"
}

Syntax Highlighting

FastC syntax is similar to C. You can use C syntax highlighting as a fallback:

1. Open a .fc file
2. Click the language mode in the status bar (bottom right)
3. Select "Configure File Association for '.fc'"
4. Choose "C"

Recommended Extensions

• C/C++ by Microsoft - Provides C syntax highlighting
• Error Lens - Inline error display

Vim/Neovim

Syntax Highlighting

Add to your .vimrc or init.vim:

" Treat .fc files as C for syntax highlighting
autocmd BufRead,BufNewFile *.fc set filetype=c

LSP with nvim-lspconfig

If using Neovim with nvim-lspconfig:

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')

-- Define FastC LSP
if not configs.fastc then
  configs.fastc = {
    default_config = {
      cmd = { '/path/to/fastc-lsp' },
      filetypes = { 'fastc' },
      root_dir = lspconfig.util.root_pattern('fastc.toml', '.git'),
    },
  }
end

lspconfig.fastc.setup{}

Add filetype detection in ~/.config/nvim/ftdetect/fastc.vim:

autocmd BufRead,BufNewFile *.fc set filetype=fastc

Emacs

Basic Setup

Add to your Emacs config:

;; Associate .fc files with c-mode for syntax highlighting
(add-to-list 'auto-mode-alist '("\\.fc\\'" . c-mode))

With eglot (LSP)

(require 'eglot)
(add-to-list 'eglot-server-programs
             '(c-mode . ("/path/to/fastc-lsp")))

Sublime Text

Syntax Highlighting

1. Open a .fc file
2. Go to View > Syntax > Open all with current extension as... > C

Build System

Create FastC.sublime-build:

{
    "cmd": ["fastc", "check", "$file"],
    "selector": "source.c",
    "file_patterns": ["*.fc"],
    "working_dir": "$file_path"
}

Command Line Workflow

If you prefer minimal editor setup, use the CLI tools:

# Check for errors
fastc check src/main.fc

# Format code
fastc fmt src/main.fc

# Build and run
fastc run

Watch Mode (with external tools)

Use watchexec or entr for auto-rebuild:

# Using watchexec
watchexec -e fc -- fastc check src/main.fc

# Using entr
find src -name '*.fc' | entr fastc check src/main.fc

LSP Features

The FastC language server provides:

• Diagnostics - Real-time error reporting
• Go to Definition - Jump to function/type definitions
• Hover Information - Type information on hover
• Document Symbols - Outline view of functions and types

Tips

1. Save frequently - The LSP checks on save
2. Use fastc check - Quick validation without full compilation
3. Format on save - Configure your editor to run fastc fmt

Troubleshooting

LSP not connecting

1. Check the server path is correct
2. Ensure the binary has execute permissions
3. Check editor's LSP logs for errors

No syntax highlighting

Ensure .fc files are associated with C syntax as a fallback.

Errors not showing

Run fastc check manually to verify the file has errors. Some editors need explicit save to trigger diagnostics.