diff options
Diffstat (limited to 'gnu/packages.scm')
| -rw-r--r-- | gnu/packages.scm | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/gnu/packages.scm b/gnu/packages.scm index e9f2540b91..8365a00051 100644 --- a/gnu/packages.scm +++ b/gnu/packages.scm @@ -33,6 +33,7 @@ %bootstrap-binaries-path fold-packages find-packages-by-name + find-best-packages-by-name find-newest-available-packages)) ;;; Commentary: @@ -148,24 +149,36 @@ then only return packages whose version is equal to VERSION." result)) '())) -(define (find-newest-available-packages) - "Return a vhash keyed by package names, and with +(define find-newest-available-packages + (memoize + (lambda () + "Return a vhash keyed by package names, and with associated values of the form (newest-version newest-package ...) where the preferred package is listed first." - ;; FIXME: Currently, the preferred package is whichever one - ;; was found last by 'fold-packages'. Find a better solution. - (fold-packages (lambda (p r) - (let ((name (package-name p)) - (version (package-version p))) - (match (vhash-assoc name r) - ((_ newest-so-far . pkgs) - (case (version-compare version newest-so-far) - ((>) (vhash-cons name `(,version ,p) r)) - ((=) (vhash-cons name `(,version ,p ,@pkgs) r)) - ((<) r))) - (#f (vhash-cons name `(,version ,p) r))))) - vlist-null)) + ;; FIXME: Currently, the preferred package is whichever one + ;; was found last by 'fold-packages'. Find a better solution. + (fold-packages (lambda (p r) + (let ((name (package-name p)) + (version (package-version p))) + (match (vhash-assoc name r) + ((_ newest-so-far . pkgs) + (case (version-compare version newest-so-far) + ((>) (vhash-cons name `(,version ,p) r)) + ((=) (vhash-cons name `(,version ,p ,@pkgs) r)) + ((<) r))) + (#f (vhash-cons name `(,version ,p) r))))) + vlist-null)))) + +(define (find-best-packages-by-name name version) + "If version is #f, return the list of packages named NAME with the highest +version numbers; otherwise, return the list of packages named NAME and at +VERSION." + (if version + (find-packages-by-name name version) + (match (vhash-assoc name (find-newest-available-packages)) + ((_ version pkgs ...) pkgs) + (#f '())))) |