Acme on 9front features a modest extension that lets the tab key produce a given number of spaces. This is almost mandatory for using Acme in certain contexts, where indenting with tabs results in anything from stern looks of disapproval to compiler warnings. For reasons of purity, the plan9port maintainers have rejected backporting this.
Luckily for you, here is some
that merges fine as of the April 2021 revision and lets you have this in p9p Acme, even documenting its interface in
acme(1). Enjoy responsibly.