zsh-completions/zsh-completions-howto.org

• 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

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

Here is a nicely formatted short tutorial showing basic usage of the _arguments function, and here is a slightly more advanced tutorial using the _arguments function. Here is the zshcompsys man page.