Add core-set, def-setting! and set!; standardized settings

core/core-set.el

@@ -0,0 +1,36 @@
+;;; core-set.el
+
+;; When we switch out feature modules, I don't want certain config segments to
+;; casue errors. This gives a
+
+(define-key help-map "\C-s" 'doom/describe-setting)
+
+(defvar doom-settings nil
+  "An alist of settings, mapping setting keywords to setter functions, which can
+be a lambda or symbol.")
+
+(defmacro def-setting! (keyword arglist &optional docstring &rest body)
+  "Define a setting macro. Takes the same arguments as `defmacro'. This should
+return forms, which will be run when `set!' is used to call this setting."
+  (declare (indent defun))
+  (unless (keywordp keyword)
+    (error "Not a valid property name: %s" name))
+  (let ((sym (intern (format "doom--set%s" keyword))))
+    (setq doom-settings (assq-delete-all keyword doom-settings))
+    `(push (cons ,keyword
+                 (defun ,sym ,arglist
+                   ,docstring
+                   ,@body))
+           doom-settings)))
+
+(defmacro set! (keyword &rest rest)
+  "Set an option defined by `doom-define-settings'. Skip if doesn't exist."
+  (declare (indent defun))
+  (let ((set-fn (cdr (assq keyword doom-settings))))
+    (when set-fn
+      (macroexp-progn
+       (mapcar (lambda (&rest args) (apply set-fn args))
+               rest)))))
+
+(provide 'core-set)
+;;; core-set.el ends here