nvi expandtab - tabs to spaces

[Derek (freebsd lists)]

Hiya,

After all these years, I'm finally wanting to switch tabs to spaces for 
certain documents (yaml comes to mind, python another), but I'm finding 
the FreeBSD nvi lacks expandtab, yet OpenBSD's (as of 6.7) supports this 
option.

What is the canonical way to use space indentation in FreeBSD's nvi?

Is there any appetite (from committers) for a patch/import of the 
feature from OpenBSD?

Thanks!