Question

Zsh completion is a rather complex beast, and I find the man-page very difficult to read, especially it’s missing (simple) examples of all the various optspec forms etc. I haven’t managed to find anything online myself yet so help would be most appreciated.

As an example here’s what I’m struggling with at the moment, and the zshcompsys man-page doesn’t offer any clarifications. I have

#compdef mtt2

_arguments -s : \
    '-h' '--help' \
    '-V' '--version' \
    ':foobars:(foo bar baz)'

Now, when I type mtt2 <TAB> I’m only offered foo, bar and baz as completions, why not -h, --help, etc, as well?
What magic do I need to pass to _arguments in order to be offered all possibilities?

Answer 1

You need to start argument that you complete with dash (I mean that argument that you type to test, not _arguments argument). You should either look at zstyle, try to pass -h and others just like :foobars: or even directly use compadd. Examples:

1. Directly using compadd:

   #compdef test
   A=( -h --help -V --version foo bar baz )
   compadd -a A
   

2. Passing -h and others just like :foobars::

   #compdef test
   A=( -h --help -V --version )
   _arguments \
       - foobars \
       ':foobars:(foo bar baz)' \
       - options \
       ":arguments:($A)"
   

   or

   A=( -h --help -V --version foo bar baz )
   _arguments \
       ":::($A)"
   

3. zstyle controls completion style. It is described in «COMPLETION SYSTEM CONFIGURATION» section in man zshcompsys and probably has an option that will enable completing of switches, but I do not know which option controls that.