Can this snippet be further improved?

[Sebastian Gniazdowski <sgniazdowski@xxxxxxxxx>]

I'm preparing update to zsh plugin standard. It's about getting the
path to the sourced (….plugin.zsh) script. The current version is:

    0=${${ZERO:-${(%):-%x}}:A}

I wonder if it could be improved? The current version:
- favors ZERO,
- falls back to %x if ZERO is empty,
- makes the path absolute,
- resolved symlinks and ,,./ components.

Is there a bug or improvement that's possible?

-- 
Best regards,
Sebastian Gniazdowski