Add Swift support to Flycheck using Swift compiler frontend. Flycheck-swift3 is designed to work with Apple swift-mode.el in the main Swift repository . Features: - Apple swift-mode.el support - Apple Swift 5.7 support If you use the toolchain option, you can use the old version of Swift. - The `xcrun' command support (only on macOS) Usage: (with-eval-after-load 'flycheck (add-hook 'flycheck-mode-hook #'flycheck-swift3-setup))