Questions tagged [boolean]

I understand that nil, 0 and/or -1 are used for disabling some features and t, 1 and/or +1 are used for enabling some features. When assigning variables or enabling/disabling minor modes, which should I choose? I have seen all of these variations…

What boolean/logical convenience functions / macros are available for Emacs Lisp in either the core set of functions or external packages? I'm interested in just about anything other than the built-in logical operators in and, or, not (null) and…

I have some basic questions about elisp. I often see something like (search-forward "something" nil 'noerror) And sometimes I see something like (search-forward "something" nil :noerror) What is the difference and should I prefer one form over…

Why does this function print non-zero integers on non-empty lines? ;; taken from https://emacs.stackexchange.com/a/16826/10896 (defun current-line-empty-p () (interactive) (setq answer (string-match-p "^\\s-*$" (thing-at-point 'line))) …