IMO, it's not practical to use directory local variable

1. directory local variable goes ".dir-local.el". But we can't mark every directory contain this file as project. We have to do extra search if we use directory local variable.

2. If we have variable "project-directory-plain-project-p", It's a problem for us to determine the root

Zhu Zihao <cjpeople2013@gmail.com> writes:

To mark a directoy as project, put an empty magic file .emacs-project under the
directory, and project.el should be responsible for it.

Is there any more standard name than ".emacs-project"? Or could a
directory local-variable be used? I like the idea, but wouldn't want to
have so many ".emacs-project" files lying around in toy projects.