Function: package-vc-install-dependencies

package-vc-install-dependencies is a byte-compiled function defined in package-vc.el.gz.

Signature

(package-vc-install-dependencies REQUIREMENTS)

Documentation

Install missing dependencies, and return missing ones.

The return value will be nil if everything was found, or a list of (NAME VERSION) pairs of all packages that couldn't be found.

REQUIREMENTS should be a list of additional requirements; each element in this list should have the form (PACKAGE VERSION-LIST), where PACKAGE is a package name and VERSION-LIST is the required version of that package.

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/package-vc.el.gz
(defun package-vc-install-dependencies (requirements)
  "Install missing dependencies, and return missing ones.
The return value will be nil if everything was found, or a list
of (NAME VERSION) pairs of all packages that couldn't be found.

REQUIREMENTS should be a list of additional requirements; each
element in this list should have the form (PACKAGE VERSION-LIST),
where PACKAGE is a package name and VERSION-LIST is the required
version of that package."
  (let ((to-install '()) (missing '()))
    (cl-labels ((search (pkg)
                  "Attempt to find all dependencies for PKG."
                  (cond
                   ((assq (car pkg) to-install)) ;inhibit cycles
                   ((package-installed-p (car pkg)))
                   ((let* ((pac package-archive-contents)
                           (desc (cadr (assoc (car pkg) pac))))
                      (if desc
                          (let ((reqs (package-desc-reqs desc)))
                            (push desc to-install)
                            (mapc #'search reqs))
                        (push pkg missing))))))
                (version-order (a b)
                  "Predicate to sort packages in order."
                  (version-list-<
                   (package-desc-version b)
                   (package-desc-version a)))
                (duplicate-p (a b)
                  "Are A and B the same package?"
                  (eq (package-desc-name a) (package-desc-name b)))
                (depends-on-p (target package)
                  "Does PACKAGE depend on TARGET?"
                  (or (eq target package)
                      (let* ((pac package-archive-contents)
                             (desc (cadr (assoc package pac))))
                        (and desc (seq-some
                                   (apply-partially #'depends-on-p target)
                                   (mapcar #'car (package-desc-reqs desc)))))))
                (dependent-order (a b)
                  (let ((desc-a (package-desc-name a))
                        (desc-b (package-desc-name b)))
                    (depends-on-p desc-a desc-b))))
      (mapc #'search requirements)
      (cl-callf sort to-install #'version-order)
      (cl-callf seq-uniq to-install #'duplicate-p)
      (cl-callf sort to-install #'dependent-order))
    (mapc #'package-install-from-archive to-install)
    missing))