Refactor def-setting!/set!; now evaluates its arguments on set!

core/autoload/set.el

@@ -0,0 +1,57 @@
+;;; set.el
+(provide 'doom-lib-set)
+
+;; This provides a centralized configuration system that a) won't evaluate its
+;; arguments if it doesn't need to (performance), b) won't complain if the
+;; setting doesn't exist and c) is more elegant than a bunch of `after!' blocks,
+;; which can cause intermittent stuttering in large quantities. I'm a fan of
+;; concise, do-what-I-mean front-facing configuration, believe it or not.
+;;
+;; Plus, it can benefit from byte-compilation.
+
+;;;###autoload
+(defvar doom-settings nil
+  "An alist of settings, mapping setting keywords to setter functions, which can
+be a lambda or symbol.")
+
+;;;###autoload
+(defmacro def-setting! (keyword arglist &optional docstring &rest forms)
+  "Define a setting macro. Like `defmacro', this should return a form to be
+executed when called with `set!'. FORMS are not evaluated until `set!' calls it."
+  (declare (indent defun) (doc-string 3))
+  (unless (keywordp keyword)
+    (error "Not a valid property name: %s" keyword))
+  (let ((sym (intern (format "doom-setting--setter%s" keyword))))
+    (setq doom-settings (assq-delete-all keyword doom-settings))
+    (prog1
+        `(progn
+           (defun ,sym ,arglist
+             ,docstring
+             ,@forms)
+           (push ',(list keyword
+                         :source (__FILE__)
+                         :docstring docstring
+                         :fn sym)
+                 doom-settings))
+      (let (byte-compile-warnings)
+        (byte-compile sym)))))
+
+;;;###autoload
+(defmacro set! (keyword &rest values)
+  "Set an option defined by `def-setting!'. Skip if doesn't exist."
+  (declare (indent defun))
+  (unless values
+    (error "Empty set! for %s" keyword))
+  (cond ((not values)
+         (error "Empty set! for %s" keyword))
+        ((not (assq keyword doom-settings))
+         (when doom-debug-mode
+           (warn "No setting found for %s" keyword)))
+        (t
+         (let* ((plist (cdr (assq keyword doom-settings)))
+                (fn (plist-get plist :fn)))
+           (if fn
+               (let ((values (eval `(list ,@values))))
+                 (apply fn values))
+             (error "No setting function where one was expected for %s" keyword))))))
+