master 2ec9f025d2: Include the number of dependencies in the install prompt

[Lars Ingebrigtsen]

branch: master
commit 2ec9f025d242cf28098cf01c532d0cf4e6bd1661
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Include the number of dependencies in the install prompt
    
    * lisp/emacs-lisp/package.el (package-menu--list-to-prompt): Add
    the info to the prompt (bug#23346).
    (package--dependencies): New function.
---
 lisp/emacs-lisp/package.el | 44 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 6c77f6f150..7f72caba65 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -2180,6 +2180,14 @@ to install it but still mark it as selected."
         (user-error "Updating aborted"))
       (mapc #'package-update updateable))))
 
+(defun package--dependencies (pkg)
+  "Return a list of all dependencies PKG has.
+This is done recursively."
+  ;; Can we have circular dependencies?  Assume "nope".
+  (when-let* ((desc (cadr (assq pkg package-archive-contents)))
+              (deps (mapcar #'car (package-desc-reqs desc))))
+    (delete-dups (apply #'nconc deps (mapcar #'package--dependencies deps)))))
+
 (defun package-strip-rcs-id (str)
   "Strip RCS version ID from the version string STR.
 If the result looks like a dotted numeric version, return it.
@@ -3572,17 +3580,34 @@ immediately."
     (setq package-menu--mark-upgrades-pending t)
     (message "Waiting for refresh to finish...")))
 
-(defun package-menu--list-to-prompt (packages)
+(defun package-menu--list-to-prompt (packages &optional include-dependencies)
   "Return a string listing PACKAGES that's usable in a prompt.
 PACKAGES is a list of `package-desc' objects.
 Formats the returned string to be usable in a minibuffer
-prompt (see `package-menu--prompt-transaction-p')."
+prompt (see `package-menu--prompt-transaction-p').
+
+If INCLUDE-DEPENDENCIES, also include the number of uninstalled
+dependencies."
   ;; The case where `package' is empty is handled in
   ;; `package-menu--prompt-transaction-p' below.
-  (format "%d (%s)"
+  (format "%d (%s)%s"
           (length packages)
-          (mapconcat #'package-desc-full-name packages " ")))
-
+          (mapconcat #'package-desc-full-name packages " ")
+          (let ((deps
+                 (seq-remove
+                  #'package-installed-p
+                  (delete-dups
+                   (apply
+                    #'nconc
+                    (mapcar (lambda (package)
+                              (package--dependencies
+                               (package-desc-name package)))
+                            packages))))))
+            (if (and include-dependencies deps)
+                (if (length= deps 1)
+                    (format " plus 1 dependency")
+                  (format " plus %d dependencies" (length deps)))
+              ""))))
 
 (defun package-menu--prompt-transaction-p (delete install upgrade)
   "Prompt the user about DELETE, INSTALL, and UPGRADE.
@@ -3591,11 +3616,14 @@ Either may be nil, but not all."
   (y-or-n-p
    (concat
     (when delete
-      (format "Packages to delete: %s.  " (package-menu--list-to-prompt 
delete)))
+      (format "Packages to delete: %s.  "
+              (package-menu--list-to-prompt delete)))
     (when install
-      (format "Packages to install: %s.  " (package-menu--list-to-prompt 
install)))
+      (format "Packages to install: %s.  "
+              (package-menu--list-to-prompt install t)))
     (when upgrade
-      (format "Packages to upgrade: %s.  " (package-menu--list-to-prompt 
upgrade)))
+      (format "Packages to upgrade: %s.  "
+              (package-menu--list-to-prompt upgrade)))
     "Proceed? ")))