Add flycheck configuration

emacs/.emacs.d/init.org

@@ -350,6 +350,51 @@ To start off, first I need to enable lexical binding.
      (add-hook 'electric-indent-local-mode-hook #'oni:switch-newline-keys)
    #+END_SRC
 
+** Flycheck
+
+   Flycheck lets me see (compiler) errors, warnings and info messages
+   while writing code.
+
+   #+BEGIN_SRC emacs-lisp
+     (ensure-library flycheck)
+   #+END_SRC
+
+   When developing packages with Cask, some special care needs to be
+   taken to ensure the checkers work correctly.
+
+   #+BEGIN_SRC emacs-lisp
+     (ensure-library flycheck-cask)
+     (add-hook 'flycheck-mode-hook 'flycheck-cask-setup)
+   #+END_SRC
+
+   I disable the pylint and pyflakes checkers because they don't seem
+   to add much except noise when used together with flake8. Also
+   pylint seems hell-bent on making Python written like a
+   statically-typed langauge.
+
+   #+BEGIN_SRC emacs-lisp
+     (with-eval-after-load 'flycheck
+       (mapc (lambda (c) (delq c flycheck-checkers))
+             '(python-pylint python-pyflakes)))
+   #+END_SRC
+
+   Also show which columns messages appear in.
+
+   #+BEGIN_SRC emacs-lisp
+     (with-eval-after-load 'flycheck
+       (setq flycheck-highlighting-mode 'columns))
+   #+END_SRC
+
+   Show the error message at point in a tooltip.
+
+   #+BEGIN_SRC emacs-lisp
+     (ensure-library flycheck-pos-tip)
+
+     (with-eval-after-load 'flycheck
+       (require 'flycheck-pos-tip)
+       (flycheck-pos-tip-mode))
+   #+END_SRC
+
 * Major modes
 
 ** Emacs lisp mode
@@ -455,6 +500,12 @@ To start off, first I need to enable lexical binding.
      (add-hook 'python-mode-hook 'electric-pair-local-mode)
    #+END_SRC
 
+   Enable syntax and style checking with flycheck.
+
+   #+BEGIN_SRC emacs-lisp
+     (add-hook 'python-mode-hook 'flycheck-mode)
+   #+END_SRC
+
 * Applications
 
 ** Magit