Add use-package-tags-load function

Author: akirak

use-package-tags-test.el

@@ -66,6 +66,13 @@
     (expect (use-package-tags-collect-tags "./tests/init.el" :sort t)
             :to-equal '(active bar foo inactive))))
 
+(describe "use-package-tags-load"
+  (xit "loads packages with a tag and add the tag to the profile")
+  (xit "If an error occurs, don't add the tag to the profile"))
+
+(describe "use-package-tags--unloaded-tags (private function)"
+  (xit "returns tags that are not in the profile"))
+
 (describe "use-package-tags--source-buffer-list (private function)"
   (describe "When t is given"
     (if (file-exists-p (expand-file-name "init.el" user-emacs-directory))

use-package-tags.el

@@ -290,5 +290,49 @@ If SORT is non-nil, the result will be lexicographically sorted."
            (cl-remove-duplicates)
            (order)))))
 
+(defun use-package-tags--unloaded-tags ()
+  "Return a list of tags that are not in the current profile."
+  (-difference (use-package-tags-collect-tags t :sort t)
+               use-package-tags-current-profile))
+
+;;;###autoload
+(defun use-package-tags-load (tag)
+  "Load packages with a TAG.
+
+This function evalates `use-package' forms with the selected tag
+in `use-package-tags-init-files'.
+
+After successfully loading all matching packages, the tag will be
+added to `use-package-tags-current-profile', without saving the value
+to `custom-file'."
+  (interactive (list (completing-read "Load packages with tag: "
+                                      (use-package-tags--unloaded-tags)
+                                      nil 'match)))
+  (cl-labels
+      ((get-keyword (prop rest) (-some->> (member prop rest)
+                                  (nth 1)))
+       (has-tag-p (tag rest)
+                  (let ((tags (cdr (get-keyword :tags rest))))
+                    (memq tag (cl-etypecase tags
+                                (list tags)
+                                (symbol (list tags)))))))
+    (setq tag (cl-etypecase tag
+                (tag tag)
+                (string (intern tag))))
+    (push tag use-package-tags-current-profile)
+    (condition-case err
+        (use-package-tags--with-package-forms
+            (use-package-tags--source-buffer-list t)
+          (let ((exp (read (current-buffer))))
+            (when (has-tag-p tag exp)
+              (message "Loading package %s configured at %s..."
+                       (nth 1 exp)
+                       (abbreviate-file-name (buffer-file-name)))
+              (eval exp))))
+      (error (progn
+               (message "Error while loading the package: %s" err)
+               (cl-delete tag use-package-tags-current-profile)
+               (error err))))))
+
 (provide 'use-package-tags)
 ;;; use-package-tags.el ends here