sq.lisp

(defmacro sq (variable value &optional (documentation nil documentation-p))
  "REPL-friendly alternative-to/merger-of setq and defparameter."
  (assert (and variable (symbolp variable)))
  (alexandria:once-only (value)
    `(cond
       ((boundp ',variable)
        ,@(when documentation-p
            `((setf (documentation ',variable 'variable) ,documentation)))
        (setf ,variable ,value))
       (t
        (defparameter ,variable ,value ,@(and documentation-p `(,documentation)))))))