Using output of command to generate autocompletion commands for zsh

Question

Hey, I'm trying to get zsh to run a git command, and use the output to generate autocomplete possibilities.

The command I'm trying to run is

git log -n 2 --pretty=format:"'%h %an'"

And here's the code I'm using:

local lines words

lines=(${(f)$(git log -n 2 --pretty=format:"'%h %an'")})
words=${(f)$(_call_program foobar git log -n 2 --pretty=format:"%h")}

echo "Length of lines is " ${#lines[@]} " value is " ${lines}
echo "Length of words is " ${#words[@]} " value is " ${words}

compadd -d lines -a -- words

This doesn't work at all...it thinks that words is a single element and lines aren't getting printed properly at all.

However, when I try to setup an array of strings by hand, it all works.

local lines words

lines=('one two' 'three')
words=('one two' 'three')

echo "Length of lines is " ${#lines[@]} " value is " ${lines}
echo "Length of words is " ${#words[@]} " value is " ${words}

compadd -d lines -a -- words

Answer 1

To force words being an array, you should use either

words=( ${(f)...} )

or

set -A words ${(f)...}

. If you use just words=${(f)...}, you will always get one value. By the way, why have you added parenthesis around ${(f)...} when you were writing lines definition, but have not done it for words?

Also, there is another thing to concern: ${(f)$(...)} should be replaced with ${(f)"$(...)"}. It is some black magic here: I don't know why first one does emit a single scalar value, while second one does emit an array of scalar values, just was pointed to this fact by someone here on stackoverflow.