How to avoid variable name collisions in my init file?

Question

I noticed spacemacs puts things like autosave and backup files in ~/.emacs.d/.cache/ and I'd like to use that idea in my own setup.

From spacemacs/core/core-load-paths.el

(defconst spacemacs-cache-directory
  (expand-file-name (concat user-emacs-directory ".cache/"))

I considered adding this to my own init.el,

(defconst cache-directory
  (expand-file-name (concat user-emacs-directory ".cache/"))

but without the "spacemacs" prefix, "cache-directory" seems like a dangerously generic name, likely to collide with something at some point.

I'm still new to emacs, and I don't know enough about scoping in elisp to say whether this is a serious concern. Should I name it something silly like "ivan-cache-directory", or is there a best practice people stick to? Or is this not actually worth worrying about?

Answer 1

Using a should-be-unique prefix is recommended.

For init file code I like to use my- because:

1. it is suitably unlikely to conflict with anything.
2. it's short, but meaningful.
3. it's not my name -- so when I share code with other people it reads just as well in their init file as it does in my own.