How to print formatted like when showing completion entries?

[Marc Cornellà <marc.cornella@xxxxxxxx>]

I'm trying to print a bunch of options to a command, and I want to show it
like triggering a completion function would do,
with the same spacing and distribution across the terminal window. I've
tried using *fmt* but I'm not satisfied with the result.

How does Zsh print the completion entries passed to *compadd*? I mean,
where can I find the logic to compute the number
of columns, divide the entries into columns and add as much separation as
needed? Much better if there is actually a Zsh
command to do that automatically.

Thanks,
Marc