Emacs major modes

I have used emacs as my main editor for around six years now. I keep my own emacs.d and regularly add, remove and configure packages. These packages consist of major and minor modes to extend emacs. I have however yet to write my own mode in emacs. From before I know that major mode allows re-binding keys, altering how text is shown and I would like learn more about how it works so I have spent the day writing games to explore major modes.

I started by looking at games other people have written and decided that a game that looked simple(st) to re-write was tictactoe.

I compiled a small repository of games from todays experimentation but to summarize the biggest things I learned was

1. elisp does not support multidimensional arrays
2. (interactive) allows a function to be called with M-x
3. defining a major mode is easy and you can even extend an existing major mode (in this case special-mode is extended to get some default values and behavior) like so:

   (define-derived-mode tictactoe-mode special-mode "tic-tac-toe"
     (define-key tictactoe-mode-map (kbd "SPC") '<function you want to call with spacebar>))
   

4. syntax highlighting is also straight forward to achieve by overloading font-lock-defaults and can be done like so:

   ;; this will highlight WINNER and hit as types while _ is highligted as constants and lables
   ;; using the highlighting specified by your emacs theme
   (setq font-lock-defaults
    '((("_" . font-lock-constant-face)
       ("WINNER\\|hit" . font-lock-type-face))))