emacs: Separate package location code.

* emacs/guix-base.el (guix-directory, guix-read-directory)
(guix-set-directory): Move to "guix-backend.el".
(guix-find-location, guix-package-location, guix-edit): Move to...
* emacs/guix-location.el: ... here.  New file.
* emacs/guix-ui-package.el: Use it.
* emacs.am (ELFILES): Add it.

emacs.am

@@ -40,6 +40,7 @@ ELFILES =					\
   emacs/guix-init.el				\
   emacs/guix-license.el				\
   emacs/guix-list.el				\
+  emacs/guix-location.el			\
   emacs/guix-messages.el			\
   emacs/guix-pcomplete.el			\
   emacs/guix-popup.el				\

emacs/guix-backend.el

@@ -82,7 +82,7 @@ If you have a slow system, try to increase this time."
   :type 'string
   :group 'guix-repl)
 
-(defcustom guix-after-start-repl-hook ()
+(defcustom guix-after-start-repl-hook '(guix-set-directory)
   "Hook called after Guix REPL is started."
   :type 'hook
   :group 'guix-repl)
@@ -336,6 +336,28 @@ additional internal REPL if it exists."
   (interactive "P")
   (geiser-repl--switch-to-buffer (guix-get-repl-buffer internal)))
 
+
+;;; Guix directory
+
+(defvar guix-directory nil
+  "Default directory with Guix source.
+If it is not set by a user, it is set after starting Guile REPL.
+This directory is used to define package locations.")
+
+(defun guix-read-directory ()
+  "Return `guix-directory' or prompt for it.
+This function is intended for using in `interactive' forms."
+  (if current-prefix-arg
+      (read-directory-name "Directory with Guix modules: "
+                           guix-directory)
+    guix-directory))
+
+(defun guix-set-directory ()
+  "Set `guix-directory' if needed."
+  (or guix-directory
+      (setq guix-directory
+            (guix-eval-read "%guix-dir"))))
+
 
 ;;; Evaluating expressions
 

emacs/guix-base.el

@@ -48,53 +48,7 @@
           (when output (concat ":" output))))
 
 
-;;; Location of packages, profiles and manifests
+;;; Location of profiles and manifests
-
-(defvar guix-directory nil
-  "Default Guix directory.
-If it is not set by a user, it is set after starting Guile REPL.
-This directory is used to define location of the packages.")
-
-(defun guix-read-directory ()
-  "Return `guix-directory' or prompt for it.
-This function is intended for using in `interactive' forms."
-  (if current-prefix-arg
-      (read-directory-name "Directory with Guix modules: "
-                           guix-directory)
-    guix-directory))
-
-(defun guix-set-directory ()
-  "Set `guix-directory' if needed."
-  (or guix-directory
-      (setq guix-directory
-            (guix-eval-read "%guix-dir"))))
-
-(add-hook 'guix-after-start-repl-hook 'guix-set-directory)
-
-(defun guix-find-location (location &optional directory)
-  "Go to LOCATION of a package.
-LOCATION is a string of the form:
-
-  \"PATH:LINE:COLUMN\"
-
-If PATH is relative, it is considered to be relative to
-DIRECTORY (`guix-directory' by default)."
-  (cl-multiple-value-bind (path line col)
-      (split-string location ":")
-    (let ((file (expand-file-name path (or directory guix-directory)))
-          (line (string-to-number line))
-          (col  (string-to-number col)))
-      (find-file file)
-      (goto-char (point-min))
-      (forward-line (- line 1))
-      (move-to-column col)
-      (recenter 1))))
-
-(defun guix-package-location (id-or-name)
-  "Return location of a package with ID-OR-NAME.
-For the meaning of location, see `guix-find-location'."
-  (guix-eval-read (guix-make-guile-expression
-                   'package-location-string id-or-name)))
 
 (defun guix-generation-file (profile generation)
   "Return the file name of a PROFILE's GENERATION."
@@ -120,20 +74,6 @@ See `guix-packages-profile'."
   (expand-file-name "manifest"
                     (guix-packages-profile profile generation system?)))
 
-;;;###autoload
-(defun guix-edit (id-or-name &optional directory)
-  "Edit (go to location of) package with ID-OR-NAME.
-See `guix-find-location' for the meaning of package location and
-DIRECTORY.
-Interactively, with prefix argument, prompt for DIRECTORY."
-  (interactive
-   (list (guix-read-package-name)
-         (guix-read-directory)))
-  (let ((loc (guix-package-location id-or-name)))
-    (if loc
-        (guix-find-location loc directory)
-      (message "Couldn't find package location."))))
-
 
 ;;; Actions on packages and generations
 

emacs/guix-location.el

@@ -0,0 +1,72 @@
+;;; guix-location.el --- Package locations
+
+;; Copyright © 2016 Alex Kost <alezost@gmail.com>
+
+;; This file is part of GNU Guix.
+
+;; GNU Guix is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public Location as published by
+;; the Free Software Foundation, either version 3 of the Location, or
+;; (at your option) any later version.
+
+;; GNU Guix is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public Location for more details.
+
+;; You should have received a copy of the GNU General Public Location
+;; along with this program.  If not, see <http://www.gnu.org/locations/>.
+
+;;; Commentary:
+
+;; This file provides the code to work with locations of Guix packages.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'guix-backend)
+(require 'guix-read)
+(require 'guix-guile)
+
+(defun guix-package-location (id-or-name)
+  "Return location of a package with ID-OR-NAME.
+For the meaning of location, see `guix-find-location'."
+  (guix-eval-read (guix-make-guile-expression
+                   'package-location-string id-or-name)))
+
+(defun guix-find-location (location &optional directory)
+  "Go to LOCATION of a package.
+LOCATION is a string of the form:
+
+  \"PATH:LINE:COLUMN\"
+
+If PATH is relative, it is considered to be relative to
+DIRECTORY (`guix-directory' by default)."
+  (cl-multiple-value-bind (path line col)
+      (split-string location ":")
+    (let ((file (expand-file-name path (or directory guix-directory)))
+          (line (string-to-number line))
+          (col  (string-to-number col)))
+      (find-file file)
+      (goto-char (point-min))
+      (forward-line (- line 1))
+      (move-to-column col)
+      (recenter 1))))
+
+;;;###autoload
+(defun guix-edit (id-or-name &optional directory)
+  "Edit (go to location of) package with ID-OR-NAME.
+See `guix-find-location' for the meaning of package location and
+DIRECTORY.
+Interactively, with prefix argument, prompt for DIRECTORY."
+  (interactive
+   (list (guix-read-package-name)
+         (guix-read-directory)))
+  (let ((loc (guix-package-location id-or-name)))
+    (if loc
+        (guix-find-location loc directory)
+      (message "Couldn't find package location."))))
+
+(provide 'guix-location)
+
+;;; guix-location.el ends here

emacs/guix-ui-package.el

@@ -38,6 +38,7 @@
 (require 'guix-hydra-build)
 (require 'guix-read)
 (require 'guix-license)
+(require 'guix-location)
 (require 'guix-profiles)
 
 (guix-ui-define-entry-type package)