diff options
Diffstat (limited to 'compat-29.el')
| -rw-r--r-- | compat-29.el | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/compat-29.el b/compat-29.el index 4010a9e..ec5b81e 100644 --- a/compat-29.el +++ b/compat-29.el @@ -171,6 +171,41 @@ This function does not move point. Also see `line-end-position'." ;;;; Defined in subr.el +(compat-defun buffer-local-restore-state (states) + "Restore values of buffer-local variables recorded in STATES. +STATES should be an object returned by `buffer-local-set-state'." + (dolist (state states) + (if (cadr state) + (set (car state) (caddr state)) + (kill-local-variable (car state))))) + +(compat-defun buffer-local-set-state--get (pairs) + "Internal helper function." + (let ((states nil)) + (while pairs + (push (list (car pairs) + (and (boundp (car pairs)) + (local-variable-p (car pairs))) + (and (boundp (car pairs)) + (symbol-value (car pairs)))) + states) + (setq pairs (cddr pairs))) + (nreverse states))) + +(compat-defmacro buffer-local-set-state (&rest pairs) + "Like `setq-local', but allow restoring the previous state of locals later. +This macro returns an object that can be passed to `buffer-local-restore-state' +in order to restore the state of the local variables set via this macro. + +\(fn [VARIABLE VALUE]...)" + (declare (debug setq)) + (unless (zerop (mod (length pairs) 2)) + (error "PAIRS must have an even number of variable/value members")) + `(prog1 + (buffer-local-set-state--get ',pairs) + (,(if (fboundp 'compat--setq-local) 'compat--setq-local 'setq-local) + ,@pairs))) + (compat-defun list-of-strings-p (object) ;; <compat-tests:lists-of-strings-p> "Return t if OBJECT is nil or a list of strings." (declare (pure t) (side-effect-free t)) |