zsh autocompletion, second parameter based on first

Question

I need to auto-complete two parameters of a function, where the second parameter depends on the first one.

An example: the first parameter of a function "foo" can have values of "a" or "b". The second parameter can have values "10" or "11" in case the first parameter is "a", and "20" and "21" in case the first parameter is "b". So the following combinations of the parameters are legal:

foo a 10
foo a 11
foo b 20
foo b 21

The combinations are known upfront (they can be hardcoded).

The zsh completion system doc is quite obscure and the great How To didn't solve my problem neither. The closest would be to use _arguments, possibly with state action, but I didn't manage to make it work.

score 2 · Answer 1 · answered Sep 19 '16 at 23:02

_arguments would make sense if you've got options mixed in with the arguments that you've described. Otherwise, just look in the $words array for the previous word - something like:

if (( CURRENT == 1 )); then
   _wanted letters expl letter compadd a b
else
  case $words[1] in
    a) numbers=( 10 11 ) ;;
    b) numbers=( 20 21 ) ;;
  esac
  _wanted numbers expl number compadd -a numbers
fi

score 0 · Answer 2 · answered Sep 20 '16 at 22:29

I solved my case with the following:

IFS='
'
local -a options
_arguments "1:first:->first" "*:next:->next"
case "$state" in
    first)
        for o in $(_command_to_autocomplete_first); do
            options+=("$o")
        done
        _describe 'values' options
    ;;
    next)
        for o in $(_command_to_complete_others $words[2]); do
            options+=("$o")
        done
        _describe 'values' options
    ;;
esac

zsh autocompletion, second parameter based on first

2 Answers2