Refactor use-package extensions to ext file

core/lib/defuns-use-package.el

@@ -0,0 +1,27 @@
+;;; defuns-use-package.el
+
+;; Meant to be loaded explicitly by core.el
+
+(defun use-package--add-keyword (keyword after)
+ (setq use-package-keywords
+  (-insert-at (-find-index (lambda (key) (eq key after)) use-package-keywords)
+   keyword use-package-keywords)))
+
+(use-package--add-keyword :after :load-path)
+
+(defalias 'use-package-normalize/:after 'use-package-normalize-symlist)
+
+(defun use-package-handler/:after (name-symbol keyword arg rest state)
+  (let ((body (use-package-process-keywords name-symbol rest state)))
+    (if (null arg)
+        body
+      (use-package-concat
+       (use-package-process-keywords name-symbol
+         (use-package-sort-keywords (use-package-plist-maybe-put rest :defer t)) state)
+       (apply #'nconc
+              (mapcar (lambda (feature)
+                        `((after! ,feature (require ',name-symbol))))
+                      (delete-dups arg)))))))
+
+(provide 'defuns-use-package)
+;;; defuns-use-package.el ends here