packages: 'specification->package+output' distinguishes "no output specified".

[jackhill/guix/guix.git] / gnu / packages.scm

diff --git a/gnu/packages.scm b/gnu/packages.scm
index 7b17e70..acb247e 100644 (file)
--- a/gnu/packages.scm
+++ b/gnu/packages.scm
@@ -32,6 +32,7 @@
                           mkdir-p))
   #:autoload   (guix profiles) (packages->manifest)
   #:use-module (guix describe)
+  #:use-module (guix deprecation)
   #:use-module (ice-9 vlist)
   #:use-module (ice-9 match)
   #:autoload   (ice-9 binary-ports) (put-bytevector)
@@ -55,6 +56,7 @@
             fold-packages
             fold-available-packages
 
+            find-newest-available-packages
             find-packages-by-name
             find-package-locations
             find-best-packages-by-name
@@ -155,23 +157,26 @@ flags."
   ;; Search path for package modules.  Each item must be either a directory
   ;; name or a pair whose car is a directory and whose cdr is a sub-directory
   ;; to narrow the search.
-  (let* ((not-colon   (char-set-complement (char-set #\:)))
-         (environment (string-tokenize (or (getenv "GUIX_PACKAGE_PATH") "")
-                                       not-colon))
-         (channels    (package-path-entries)))
+  (let*-values (((not-colon)
+                 (char-set-complement (char-set #\:)))
+                ((environment)
+                 (string-tokenize (or (getenv "GUIX_PACKAGE_PATH") "")
+                                  not-colon))
+                ((channels-scm channels-go)
+                 (package-path-entries)))
     ;; Automatically add channels and items from $GUIX_PACKAGE_PATH to Guile's
     ;; search path.  For historical reasons, $GUIX_PACKAGE_PATH goes to the
     ;; front; channels go to the back so that they don't override Guix' own
     ;; modules.
     (set! %load-path
-      (append environment %load-path channels))
+      (append environment %load-path channels-scm))
     (set! %load-compiled-path
-      (append environment %load-compiled-path channels))
+      (append environment %load-compiled-path channels-go))
 
     (make-parameter
      (append environment
              %default-package-module-path
-             channels))))
+             channels-scm))))
 
 (define %patch-path
   ;; Define it after '%package-module-path' so that '%load-path' contains user
@@ -183,6 +188,29 @@ flags."
               directory))
         %load-path)))
 
+;; This procedure is used by Emacs-Guix up to 0.5.1.1, so keep it for now.
+;; See <https://github.com/alezost/guix.el/issues/30>.
+(define-deprecated find-newest-available-packages
+  find-packages-by-name
+  (mlambda ()
+    "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."
+    (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 (fold-available-packages proc init)
   "Fold PROC over the list of available packages.  For each available package,
 PROC is called along these lines:
@@ -506,14 +534,18 @@ optionally contain a version number and an output name, as in these examples:
   guile@2.0.9:debug
 
 If SPEC does not specify a version number, return the preferred newest
-version; if SPEC does not specify an output, return OUTPUT."
+version; if SPEC does not specify an output, return OUTPUT.
+
+When OUTPUT is false and SPEC does not specify any output, return #f as the
+output."
   (let-values (((name version sub-drv)
                 (package-specification->name+version+output spec output)))
     (match (%find-package spec name version)
       (#f
        (values #f #f))
       (package
-       (if (member sub-drv (package-outputs package))
+       (if (or (and (not output) (not sub-drv))
+               (member sub-drv (package-outputs package)))
            (values package sub-drv)
            (leave (G_ "package `~a' lacks output `~a'~%")
                   (package-full-name package)