Zsh’s autocompletion options from variable

General overview

I have to set a values auto-completion in zsh for a command (in the following minimal example, I will show it with testcmd). So my current code work quiet well with hardcoded values:

Current auto-completion code (the one who works)

function testcmd()
{
    echo "Nothing to do, just a test command"
}


_test_complete() {
    _values \
        "Possible values" \
        foo'[Foo]' \
        bar'[Bar baz]' \
}

compdef _test_complete testcmd

Current auto-completion behavior

When I type testcmd <tab>, I correctly get the following desired rendering:

$ testcmd
Possible values
bar  -- Bar baz
foo  -- Foo

What is the goal I search to reach

But as you see, the values are hard-coded inside the function, ideally, the function should retrieve them from a variable.

What I already try

So naturaly, I put the values inside the variable values_variable as following:

The tried code (the one who doesn’t works)

function testcmd()
{
    echo "Nothing to do, just a test command"
}


_test_complete() {
    local values_variable
    values_variable="foo'[Foo]' \
        bar'[Bar baz]' \ "
    _values \
        "Possible values" \
        ${values_variable}
}

compdef _test_complete testcmd

The behavior of the tried code

But then, when I try testcmd <tab> it completely fail:

$ testcmd
_values:compvalues:11: invalid value definition: foo'[Foo]' \t\tbar'[Bar baz]' \
_values:compvalues:11: invalid value definition: foo'[Foo]' \t\tbar'[Bar baz]' \
_values:compvalues:11: invalid value definition: foo'[Foo]' \t\tbar'[Bar baz]' \
$ testcmd 

What I also did

• I tried to escape the spaces with echo ${values_variable} | sed "s/ /\\ /g" ;
• I tried to use $values_variable with the eval command to pretend as if it content was directly typed inside the _values definition ;
• I tried both eval and escaping with eval $(echo ${values_variable} | sed "s/ /\\ /g") ;
• I tried to eveal line by line with a loop :

echo "$values_variable" | while read -r line; do
    eval "$line"
  done

• Expansion with ${(@f)values_variable}̀ ;
• Many other ideas. But it also failed.

The nearest solution I found

In How to pass the contents of a file using cat to _values (zsh completion) tread I found a solution for values imported from an external file, but the user seems to be fronted to the same space escape problem. However, I can’t adjust it to the case with the $values_variables internal variable.

I naturally tried this one, who doesn’t works either:

_test_complete() {
    local values_variable
    values_variable="foo'[Foo]' \
        bar'[Bar baz]' \ "
    OLD_IFS=$IFS
    IFS=$'\n'
    _values \
        "Possible values" \
        ${values_variable}
    IFS=$OLD_IFS
}

The question

How can I load the values to give to _values inside auto-completion function from a variable?