* Intro
** Defining completion functions
* Utility functions with example code
** compadd
** _gnu_generic
** _arguments
** _regex_arguments
** _regex_words
** _values
** _comma_separated
* Putting it all together
* Other resources
Nicely formatted short tutorial showing basic usage of the _arguments function: http://wikimatze.de/writing-zsh-completion-for-padrino.html
A slightly more advanced tutorial showing usage of the _arguments function: http://www.linux-mag.com/id/1106/
zshcompsys man page: http://linux.die.net/man/1/zshcompsys