Yes that makes sense, thanks.

Also, my comment was about the amount of boilerplate required, but that can be vastly reduced by writing `process_template` in a more functional style instead of the highly-imperative (Golang-like?) style used in the article. The first `process_template` example is just:

    def process_template(template: Template) -> str:
        return ''.join(interleave_longest(template.strings, map(process_value, template.values)))

And the second is something like:

    def process_template(template: Template) -> tuple[str, tuple]:
        return (
            ''.join(interleave_longest(template.strings, ['?'] * len(template.values))),
            map(process_value, template.values)
        )