Add Emacs user interface.

* configure.ac (emacsuidir): New variable.
  (AC_CONFIG_FILES): Add 'emacs/guix-init.el', 'emacs/guix-helper.scm'.
* Makefile.am: Include 'emacs.am'.
* emacs.am: New file.
* doc/emacs.texi: New file.
* doc/guix.texi: Include 'emacs.texi'.
* emacs/guix-backend.el: New file.
* emacs/guix-base.el: New file.
* emacs/guix-helper.scm.in: New file.
* emacs/guix-history.el: New file.
* emacs/guix-info.el: New file.
* emacs/guix-init.el.in: New file.
* emacs/guix-list.el: New file.
* emacs/guix-main.scm: New file.
* emacs/guix-utils.el: New file.
* emacs/guix.el: New file.

.gitignore

@@ -105,3 +105,8 @@ GTAGS
 /nix-setuid-helper
 /nix/scripts/guix-authenticate
 /nix/scripts/offload
+/emacs/Makefile.in
+/emacs/Makefile
+/emacs/guix-autoloads.el
+/emacs/guix-helper.scm
+/emacs/guix-init.el

Makefile.am

@@ -277,6 +277,10 @@ AM_DISTCHECK_CONFIGURE_FLAGS =			\
   --with-nix-prefix="$(NIX_PREFIX)"		\
   --enable-daemon
 
+dist_emacsui_DATA = emacs/guix-main.scm
+nodist_emacsui_DATA = emacs/guix-helper.scm
+include emacs.am
+
 dist-hook: sync-descriptions gen-ChangeLog assert-no-store-file-names
 distcheck-hook: assert-binaries-available assert-final-inputs-self-contained
 

configure.ac

@@ -174,4 +174,11 @@ AC_CONFIG_FILES([scripts/guix], [chmod +x scripts/guix])
 AC_CONFIG_FILES([pre-inst-env], [chmod +x pre-inst-env])
 AC_CONFIG_FILES([test-env],     [chmod +x test-env])
 
+dnl Emacs interface.
+AM_PATH_LISPDIR
+emacsuidir="${guilemoduledir}/guix/emacs"
+AC_SUBST([emacsuidir])
+AC_CONFIG_FILES([emacs/guix-init.el
+                 emacs/guix-helper.scm])
+
 AC_OUTPUT

doc/emacs.texi

@@ -0,0 +1,321 @@
+@node Emacs Interface
+@section Emacs Interface
+
+@cindex emacs
+GNU Guix comes with a visual user interface for GNU@tie{}Emacs, known
+as ``guix.el''.  It can be used for routine package management tasks,
+pretty much like the @command{guix package} command (@pxref{Invoking
+guix package}).  Specifically, ``guix.el'' makes it easy to:
+
+@itemize
+@item browse and display packages and generations;
+@item search, install, upgrade and remove packages;
+@item display packages from previous generations;
+@item do some other useful things.
+@end itemize
+
+@menu
+* Initial Setup: emacs Initial Setup.	Preparing @file{~/.emacs}.
+* Usage: emacs Usage.			Using the interface.
+* Configuration: emacs Configuration.	Configuring the interface.
+@end menu
+
+@node emacs Initial Setup
+@subsection Initial Setup
+
+To be able to use ``guix.el'', you need to install the following
+packages:
+
+@itemize
+@item
+@uref{http://www.gnu.org/software/emacs/, GNU Emacs}, version 24.3 or
+later;
+
+@item
+@uref{http://nongnu.org/geiser/, Geiser}, version 0.3 or later: it is
+used for interacting with the Guile process.
+
+@end itemize
+
+When it is done, add the following into your init file (@pxref{Init
+File,,, emacs, The Emacs Editor}):
+
+@example
+(require 'guix-init nil t)
+@end example
+
+However there is a chance that @code{load-path} of your Emacs does not
+contain a directory with ``guix.el'' (usually it is
+@file{/usr/share/emacs/site-lisp/}).  In that case you need to add it
+before requiring (@pxref{Lisp Libraries,,, emacs, The Emacs Editor}):
+
+@example
+(add-to-list 'load-path "/path/to/directory-with-guix.el")
+(require 'guix-init)
+@end example
+
+Do not worry about the efficiency of that @code{require} thing.  It will
+not load the whole ``guix.el'' package, it will just autoload the main
+interactive commands (@pxref{Autoload,,, elisp, Emacs Lisp}).
+
+
+@node emacs Usage
+@subsection Usage
+
+Once ``guix.el'' has been successfully configured, you should be able to
+use commands for displaying packages and generations.  This information
+can be displayed in a ``list'' or ``info'' buffer.
+
+@menu
+* Commands: emacs Commands.			@kbd{M-x guix-@dots{}}
+* General information: emacs General info.	Common for both interfaces.
+* ``List'' buffer: emacs List buffer.		List-like interface.
+* ``Info'' buffer: emacs Info buffer.		Help-like interface.
+@end menu
+
+@node emacs Commands
+@subsubsection Commands
+
+You may use the following commands to display packages and generations:
+
+@table @kbd
+@item M-x guix-all-available-packages
+@itemx M-x guix-newest-available-packages
+Display all/newest available packages.
+
+@item M-x guix-installed-packages
+Display all packages installed in the current profile.
+
+@item M-x guix-obsolete-packages
+Display obsolete packages (the packages that are installed in the
+current profile but cannot be found among available packages).
+
+@item M-x guix-search-by-name
+Display package(s) with the specified name.
+
+@item M-x guix-search-by-regexp
+Search for packages by a specified regexp.  By default ``name'',
+``synopsis'' and ``description'' of the packages will be searched.  This
+can be changed by modifying @code{guix-search-params} variable.
+
+@item M-x guix-generations
+List generations for the current profile.  With numeric prefix, show so
+many last generations.
+
+@end table
+
+It is possible to change the currently used profile with
+@kbd{M-x@tie{}guix-set-current-profile}.  This has the same effect as
+specifying @code{--profile} option for @command{guix package}
+(@pxref{Invoking guix package}).
+
+@node emacs General info
+@subsubsection General information
+
+The following keys are available for both ``list'' and ``info'' types of
+buffers:
+
+@table @kbd
+@item l
+@itemx r
+Go backward/forward by the history of the displayed results (this
+history is similar to the history of the Emacs @code{help-mode} or
+@code{Info-mode}).
+
+@item g
+Revert current buffer: update information about the displayed
+packages/generations and redisplay it.
+
+@item R
+Redisplay current buffer (without updating information).
+
+@item C-c C-z
+Go to the Guix REPL (@pxref{The REPL,,, geiser, Geiser User Manual}).
+
+@item h
+@itemx ?
+Describe current mode to see all available bindings.
+
+@end table
+
+@emph{Hint:} If you need several ``list'' or ``info'' buffers, you can
+simlpy @kbd{M-x clone-buffer} them, and each buffer will have its own
+history.
+
+@emph{Warning:} Name/version pairs cannot be used to identify packages
+(because a name is not necessarily unique), so ``guix.el'' uses special
+identifiers that live only during a guile session, so if the Guix REPL
+was restarted, you may want to revert ``list'' buffer (by pressing
+@kbd{g}).
+
+@node emacs List buffer
+@subsubsection ``List'' buffer
+
+An interface of a ``list'' buffer is similar to the interface provided
+by ``package.el'' (@pxref{Package Menu,,, emacs, The Emacs Editor}).
+
+Default key bindings available for both ``package-list'' and
+``generation-list'' buffers:
+
+@table @kbd
+@item m
+Mark the current entry.
+@item M
+Mark all entries.
+@item u
+Unmark the current entry.
+@item @key{DEL}
+Unmark backward.
+@item U
+Unmark all entries.
+@item S
+Sort entries by a specified column.
+@end table
+
+A ``package-list'' buffer additionally provides the following bindings:
+
+@table @kbd
+@item @key{RET}
+Describe marked packages (display available information in a
+``package-info'' buffer).
+@item i
+Mark a package for installation (with prefix, prompt for output(s) to
+install).
+@item d
+Mark a package for deletion.
+@item ^
+Mark a package for upgrading.
+@item x
+Execute actions on marked packages.
+@end table
+
+A ``generation-list'' buffer additionally provides the following
+bindings:
+
+@table @kbd
+@item @key{RET}
+List packages installed in the current generation.
+@item i
+Describe marked generations (display available information in a
+``generation-info'' buffer).
+@end table
+
+@node emacs Info buffer
+@subsubsection ``Info'' buffer
+
+The interface of an ``info'' buffer is similar to the interface of
+@code{help-mode} (@pxref{Help Mode,,, emacs, The Emacs Editor}).
+
+``Info'' buffer contains some buttons (as usual you may use @key{TAB} /
+@kbd{S-@key{TAB}} to move between buttons---@pxref{Mouse References,,,
+emacs, The Emacs Editor}) which can be used to:
+
+@itemize @bullet
+@item (in a ``package-info'' buffer)
+
+@itemize @minus
+@item install/remove a package;
+@item jump to a package location;
+@item browse home page of a package;
+@item describe packages from ``Inputs'' fields.
+@end itemize
+
+@item (in a ``generation-info'' buffer)
+
+@itemize @minus
+@item remove a generation;
+@item list packages installed in a generation;
+@item jump to a generation directory.
+@end itemize
+
+@end itemize
+
+
+@node emacs Configuration
+@subsection Configuration
+
+There are many variables you can modify to change the appearance or
+behavior of Emacs user interface.  Some of these variables are described
+in this section.  Also you can use Custom Interface (@pxref{Easy
+Customization,,, emacs, The Emacs Editor}) to explore/set variables (not
+all) and faces.
+
+@menu
+* Guile and Build Options: emacs Build Options.	Specifying how packages are built.
+* Keymaps: emacs Keymaps.		Configuring key bindings.
+* Appearance: emacs Appearance.		Settings for visual appearance.
+@end menu
+
+@node emacs Build Options
+@subsubsection Guile and Build Options
+
+@table @code
+@item guix-guile-program
+If you have some special needs for starting a Guile process, you may set
+this variable, for example:
+
+@example
+(setq guix-guile-program '("/bin/guile" "--no-auto-compile"))
+@end example
+
+@item guix-use-substitutes
+Has the same meaning as @code{--no-substitutes} option (@pxref{Invoking
+guix build}).
+
+@item guix-dry-run
+Has the same meaning as @code{--dry-run} option (@pxref{Invoking guix
+build}).
+
+@end table
+
+@node emacs Keymaps
+@subsubsection Keymaps
+
+If you want to change default key bindings, use the following keymaps
+(@pxref{Init Rebinding,,, emacs, The Emacs Editor}):
+
+@table @code
+@item guix-list-mode-map
+Parent keymap with general keys for ``list'' buffers.
+
+@item guix-package-list-mode-map
+Keymap with specific keys for ``package-list'' buffers.
+
+@item guix-generation-list-mode-map
+Keymap with specific keys for ``generation-list'' buffers.
+
+@item guix-info-mode-map
+Parent keymap with general keys for ``info'' buffers.
+
+@item guix-package-info-mode-map
+Keymap with specific keys for ``package-info'' buffers.
+
+@item guix-generation-info-mode-map
+Keymap with specific keys for ``generation-info'' buffers.
+
+@end table
+
+@node emacs Appearance
+@subsubsection Appearance
+
+You can change almost any aspect of ``list'' / ``info'' buffers using
+the following variables:
+
+@table @code
+@item guix-list-column-format
+@itemx guix-list-column-titles
+@itemx guix-list-column-value-methods
+Specify the columns, their names, what and how is displayed in ``list''
+buffers.
+
+@item guix-info-displayed-params
+@itemx guix-info-insert-methods
+@itemx guix-info-ignore-empty-vals
+@itemx guix-info-param-title-format
+@itemx guix-info-multiline-prefix
+@itemx guix-info-indent
+@itemx guix-info-fill-column
+@itemx guix-info-delimiter
+Various settings for ``info'' buffers.
+
+@end table

doc/guix.texi

@@ -581,6 +581,7 @@ management tools it provides.
 @menu
 * Features::                    How Guix will make your life brighter.
 * Invoking guix package::       Package installation, removal, etc.
+* Emacs Interface::             Package management from Emacs.
 * Substitutes::                 Downloading pre-built binaries.
 * Packages with Multiple Outputs::  Single source package, multiple outputs.
 * Invoking guix gc::            Running the garbage collector.
@@ -955,6 +956,8 @@ Finally, since @command{guix package} may actually start build
 processes, it supports all the common build options that @command{guix
 build} supports (@pxref{Invoking guix build, common build options}).
 
+@include emacs.texi
+
 @node Substitutes
 @section Substitutes
 

emacs.am

@@ -0,0 +1,43 @@
+# GNU Guix --- Functional package management for GNU
+# Copyright © 2014 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 License as published by
+# the Free Software Foundation; either version 3 of the License, 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 License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+AUTOLOADS = emacs/guix-autoloads.el
+
+ELFILES =					\
+  emacs/guix-backend.el				\
+  emacs/guix-base.el				\
+  emacs/guix-history.el				\
+  emacs/guix-info.el				\
+  emacs/guix-list.el				\
+  emacs/guix-utils.el				\
+  emacs/guix.el
+
+dist_lisp_DATA =				\
+  $(ELFILES)					\
+  $(AUTOLOADS)
+
+nodist_lisp_DATA =				\
+  emacs/guix-init.el
+
+$(AUTOLOADS): $(ELFILES)
+	$(EMACS) --batch --eval						\
+	  "(let ((backup-inhibited t)					\
+	         (generated-autoload-file				\
+	          (expand-file-name \"$(AUTOLOADS)\" \"$(srcdir)\")))	\
+	     (update-directory-autoloads				\
+	      (expand-file-name \"emacs\" \"$(srcdir)\")))"

emacs/guix-backend.el

@@ -0,0 +1,301 @@
+;;; guix-backend.el --- Communication with Geiser
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides the code for interacting with Guile using Geiser.
+
+;; By default (if `guix-use-guile-server' is non-nil) 2 Geiser REPLs are
+;; started.  The main one (with "guile --listen" process) is used for
+;; "interacting" with a user - for showing a progress of
+;; installing/deleting Guix packages.  The second (internal) REPL is
+;; used for synchronous evaluating, e.g. when information about
+;; packages/generations should be received for a list/info buffer.
+;;
+;; This "2 REPLs concept" makes it possible to have a running process of
+;; installing/deleting packages and to continue to search/list/get info
+;; about other packages at the same time.  If you prefer to use a single
+;; Guix REPL, do not try to receive any information while there is a
+;; running code in the REPL (see
+;; <https://github.com/jaor/geiser/issues/28>).
+;;
+;; If you need to use "guix.el" in another Emacs (i.e. when there is
+;; a runnig "guile --listen..." REPL somewhere), you can either change
+;; `guix-default-port' in that Emacs instance or set
+;; `guix-use-guile-server' to t.
+;;
+;; Guix REPLs (unlike the usual Geiser REPLs) are not added to
+;; `geiser-repl--repls' variable, and thus cannot be used for evaluating
+;; while editing scm-files.  The only purpose of Guix REPLs is to be an
+;; intermediate between "Guix/Guile level" and "Emacs interface level".
+;; That being said you can still want to use a Guix REPL while hacking
+;; auxiliary scheme-files for "guix.el".  You can just use "M-x
+;; connect-to-guile" (connect to "localhost" and `guix-default-port') to
+;; have a usual Geiser REPL with all stuff defined by "guix.el" package.
+
+;;; Code:
+
+(require 'geiser-mode)
+
+(defvar guix-load-path
+  (file-name-directory (or load-file-name
+                           (locate-library "guix")))
+  "Directory with scheme files for \"guix.el\" package.")
+
+(defvar guix-helper-file
+  (expand-file-name "guix-helper.scm" guix-load-path)
+  "Auxiliary scheme file for loading.")
+
+(defvar guix-guile-program (or geiser-guile-binary "guile")
+  "Name of the guile executable used for Guix REPL.
+May be either a string (the name of the executable) or a list of
+strings of the form:
+
+  (NAME . ARGS)
+
+Where ARGS is a list of arguments to the guile program.")
+
+
+;;; REPL
+
+(defgroup guix-repl nil
+  "Settings for Guix REPLs."
+  :prefix "guix-repl-"
+  :group 'guix)
+
+(defcustom guix-repl-startup-time 30000
+  "Time, in milliseconds, to wait for Guix REPL to startup.
+Same as `geiser-repl-startup-time' but is used for Guix REPL.
+If you have a slow system, try to increase this time."
+  :type 'integer
+  :group 'guix-repl)
+
+(defcustom guix-repl-buffer-name "*Guix REPL*"
+  "Default name of a Geiser REPL buffer used for Guix."
+  :type 'string
+  :group 'guix-repl)
+
+(defcustom guix-after-start-repl-hook ()
+  "Hook called after Guix REPL is started."
+  :type 'hook
+  :group 'guix-repl)
+
+(defcustom guix-use-guile-server t
+  "If non-nil, start guile with '--listen' argument.
+This allows to receive information about packages using an additional
+REPL while some packages are being installed/removed in the main REPL."
+  :type 'boolean
+  :group 'guix-repl)
+
+(defcustom guix-default-port 37246
+  "Default port used if `guix-use-guile-server' is non-nil."
+  :type 'integer
+  :group 'guix-repl)
+
+(defvar guix-repl-buffer nil
+  "Main Geiser REPL buffer used for communicating with Guix.
+This REPL is used for processing package actions and for
+receiving information if `guix-use-guile-server' is nil.")
+
+(defvar guix-internal-repl-buffer nil
+  "Additional Geiser REPL buffer used for communicating with Guix.
+This REPL is used for receiving information only if
+`guix-use-guile-server' is non-nil.")
+
+(defvar guix-internal-repl-buffer-name "*Guix Internal REPL*"
+  "Default name of an internal Guix REPL buffer.")
+
+(defun guix-get-guile-program (&optional internal)
+  "Return a value suitable for `geiser-guile-binary'."
+  (if (or internal
+          (not guix-use-guile-server))
+      guix-guile-program
+    (append (if (listp guix-guile-program)
+                guix-guile-program
+              (list guix-guile-program))
+            ;; Guile understands "--listen=..." but not "--listen ..."
+            (list (concat "--listen="
+                          (number-to-string guix-default-port))))))
+
+(defun guix-start-process-maybe ()
+  "Start Geiser REPL configured for Guix if needed."
+  (guix-start-repl-maybe)
+  (if guix-use-guile-server
+      (guix-start-repl-maybe 'internal)
+    (setq guix-internal-repl-buffer guix-repl-buffer)))
+
+(defun guix-start-repl-maybe (&optional internal)
+  "Start Guix REPL if needed.
+If INTERNAL is non-nil, start an internal REPL."
+  (let* ((repl-var (guix-get-repl-buffer-variable internal))
+         (repl (symbol-value repl-var)))
+    (unless (and (buffer-live-p repl)
+                 (get-buffer-process repl))
+      ;; Kill REPL buffer with a dead process
+      (and (buffer-live-p repl) (kill-buffer repl))
+      (or internal
+          (message "Starting Geiser REPL for Guix ..."))
+      (let ((geiser-guile-binary (guix-get-guile-program internal))
+            (geiser-guile-init-file (or internal guix-helper-file))
+            (repl (get-buffer-create
+                   (guix-get-repl-buffer-name internal))))
+        (condition-case err
+            (guix-start-repl repl
+                             (and internal
+                                  (geiser-repl--read-address
+                                   "localhost" guix-default-port)))
+          (text-read-only
+           (error (concat "Couldn't start Guix REPL.  Perhaps the port %s is busy.\n"
+                          "See buffer '%s' for details")
+                  guix-default-port (buffer-name repl))))
+        (set repl-var repl)
+        (unless internal
+          (message "Guix REPL has been started.")
+          (run-hooks 'guix-after-start-repl-hook))))))
+
+(defun guix-start-repl (buffer &optional address)
+  "Start Guix REPL in BUFFER.
+If ADDRESS is non-nil, connect to a remote guile process using
+this address (it should be defined by
+`geiser-repl--read-address')."
+  ;; A mix of the code from `geiser-repl--start-repl' and
+  ;; `geiser-repl--to-repl-buffer'.
+  (let ((impl 'guile)
+        (geiser-guile-load-path (list guix-load-path))
+        (geiser-repl-startup-time guix-repl-startup-time))
+    (with-current-buffer buffer
+      (geiser-repl-mode)
+      (geiser-impl--set-buffer-implementation impl)
+      (geiser-repl--autodoc-mode -1)
+      (goto-char (point-max))
+      (let* ((prompt-re (geiser-repl--prompt-regexp impl))
+             (deb-prompt-re (geiser-repl--debugger-prompt-regexp impl))
+             (prompt (geiser-con--combined-prompt prompt-re deb-prompt-re)))
+        (or prompt-re
+            (error "Oh no! Guix REPL in the buffer '%s' has not been started"
+                   (buffer-name buffer)))
+        (geiser-repl--save-remote-data address)
+        (geiser-repl--start-scheme impl address prompt)
+        (geiser-repl--quit-setup)
+        (geiser-repl--history-setup)
+        (setq-local geiser-repl--repls (list buffer))
+        (geiser-repl--set-this-buffer-repl buffer)
+        (setq geiser-repl--connection
+              (geiser-con--make-connection
+               (get-buffer-process (current-buffer))
+               prompt-re
+               deb-prompt-re))
+        (geiser-repl--startup impl address)
+        (geiser-repl--autodoc-mode 1)
+        (geiser-company--setup geiser-repl-company-p)
+        (add-hook 'comint-output-filter-functions
+                  'geiser-repl--output-filter
+                  nil t)
+        (set-process-query-on-exit-flag
+         (get-buffer-process (current-buffer))
+         geiser-repl-query-on-kill-p)))))
+
+(defun guix-get-repl-buffer (&optional internal)
+  "Return Guix REPL buffer; start REPL if needed.
+If INTERNAL is non-nil, return an additional internal REPL."
+  (guix-start-process-maybe)
+  (let ((repl (symbol-value (guix-get-repl-buffer-variable internal))))
+    ;; If a new Geiser REPL is started, `geiser-repl--repl' variable may
+    ;; be set to the new value in a Guix REPL, so set it back to a
+    ;; proper value here.
+    (with-current-buffer repl
+      (geiser-repl--set-this-buffer-repl repl))
+    repl))
+
+(defun guix-get-repl-buffer-variable (&optional internal)
+  "Return the name of a variable with a REPL buffer."
+  (if internal
+      'guix-internal-repl-buffer
+    'guix-repl-buffer))
+
+(defun guix-get-repl-buffer-name (&optional internal)
+  "Return the name of a REPL buffer."
+  (if internal
+      guix-internal-repl-buffer-name
+    guix-repl-buffer-name))
+
+(defun guix-switch-to-repl (&optional internal)
+  "Switch to Guix REPL.
+If INTERNAL is non-nil (interactively with prefix), switch to the
+additional internal REPL if it exists."
+  (interactive "P")
+  (geiser-repl--switch-to-buffer (guix-get-repl-buffer internal)))
+
+
+;;; Evaluating expressions
+
+(defun guix-make-guile-expression (fun &rest args)
+  "Return string containing a guile expression for calling FUN with ARGS."
+  (format "(%S %s)" fun
+          (mapconcat
+           (lambda (arg)
+             (cond
+              ((null arg) "'()")
+              ((or (eq arg t)
+                   ;; An ugly hack to separate 'false' from nil
+                   (equal arg 'f)
+                   (keywordp arg))
+               (concat "#" (prin1-to-string arg t)))
+              ((or (symbolp arg) (listp arg))
+               (concat "'" (prin1-to-string arg)))
+              (t (prin1-to-string arg))))
+           args
+           " ")))
+
+(defun guix-eval (str &optional wrap)
+  "Evaluate guile expression STR.
+If WRAP is non-nil, wrap STR into (begin ...) form.
+Return a list of strings with result values of evaluation."
+  (with-current-buffer (guix-get-repl-buffer 'internal)
+    (let* ((wrapped (if wrap (geiser-debug--wrap-region str) str))
+           (code `(:eval (:scm ,wrapped)))
+           (ret (geiser-eval--send/wait code)))
+      (if (geiser-eval--retort-error ret)
+          (error "Error in evaluating guile expression: %s"
+                 (geiser-eval--retort-output ret))
+        (cdr (assq 'result ret))))))
+
+(defun guix-eval-read (str &optional wrap)
+  "Evaluate guile expression STR.
+For the meaning of WRAP, see `guix-eval'.
+Return elisp expression of the first result value of evaluation."
+  ;; Parsing scheme code with elisp `read' is probably not the best idea.
+  (read (replace-regexp-in-string
+         "#f\\|#<unspecified>" "nil"
+         (replace-regexp-in-string
+          "#t" "t" (car (guix-eval str wrap))))))
+
+(defun guix-eval-in-repl (str)
+  "Switch to Guix REPL and evaluate STR with guile expression there."
+  (let ((repl (guix-get-repl-buffer)))
+    (with-current-buffer repl
+      (delete-region (geiser-repl--last-prompt-end) (point-max))
+      (goto-char (point-max))
+      (insert str)
+      (geiser-repl--send-input))
+    (geiser-repl--switch-to-buffer repl)))
+
+(provide 'guix-backend)
+
+;;; guix-backend.el ends here

emacs/guix-base.el

@@ -0,0 +1,607 @@
+;;; guix-base.el --- Common definitions
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides some base and common definitions for guix.el
+;; package.
+
+;; List and info buffers have many common patterns that are defined
+;; using `guix-define-buffer-type' macro from this file.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'guix-backend)
+(require 'guix-utils)
+
+
+;;; Profiles
+
+(defvar guix-user-profile
+  (expand-file-name "~/.guix-profile")
+  "User profile.")
+
+(defvar guix-default-profile
+  (concat (or (getenv "NIX_STATE_DIR") "/var/guix")
+          "/profiles/per-user/"
+          (getenv "USER")
+          "/guix-profile")
+  "Default Guix profile.")
+
+(defvar guix-current-profile guix-default-profile
+  "Current profile.")
+
+(defun guix-set-current-profile (path)
+  "Set `guix-current-profile' to PATH.
+Interactively, prompt for PATH.  With prefix, use
+`guix-default-profile'."
+  (interactive
+   (list (if current-prefix-arg
+             guix-default-profile
+           (read-file-name "Set profile: "
+                           (file-name-directory guix-current-profile)))))
+  (let ((path (directory-file-name (expand-file-name path))))
+    (setq guix-current-profile
+          (if (string= path guix-user-profile)
+              guix-default-profile
+            path))
+    (message "Current profile has been set to '%s'."
+             guix-current-profile)))
+
+
+;;; Parameters of the entries
+
+(defvar guix-param-titles
+  '((package
+     (id                . "ID")
+     (name              . "Name")
+     (version           . "Version")
+     (license           . "License")
+     (synopsis          . "Synopsis")
+     (description       . "Description")
+     (home-url          . "Home page")
+     (outputs           . "Outputs")
+     (inputs            . "Inputs")
+     (native-inputs     . "Native inputs")
+     (propagated-inputs . "Propagated inputs")
+     (location          . "Location")
+     (installed         . "Installed"))
+    (installed
+     (path              . "Installed path")
+     (dependencies      . "Dependencies")
+     (output            . "Output"))
+    (generation
+     (id                . "ID")
+     (number            . "Number")
+     (prev-number       . "Previous number")
+     (path              . "Path")
+     (time              . "Time")))
+  "List for defining titles of entry parameters.
+Titles are used for displaying information about entries.
+Each element of the list has a form:
+
+  (ENTRY-TYPE . ((PARAM . TITLE) ...))")
+
+(defun guix-get-param-title (entry-type param)
+  "Return title of an ENTRY-TYPE entry parameter PARAM."
+  (or (guix-get-key-val guix-param-titles
+                        entry-type param)
+      (prog1 (symbol-name param)
+        (message "Couldn't find title for '%S %S'."
+                 entry-type param))))
+
+(defun guix-get-name-spec (name version &optional output)
+  "Return Guix package specification by its NAME, VERSION and OUTPUT."
+  (concat name "-" version
+          (when output (concat ":" output))))
+
+(defun guix-get-full-name (entry &optional output)
+  "Return name specification of the package ENTRY and OUTPUT."
+  (guix-get-name-spec (guix-get-key-val entry 'name)
+                      (guix-get-key-val entry 'version)
+                      output))
+
+(defun guix-get-installed-outputs (entry)
+  "Return list of installed outputs for the package ENTRY."
+  (mapcar (lambda (installed-entry)
+            (guix-get-key-val installed-entry 'output))
+          (guix-get-key-val entry 'installed)))
+
+(defun guix-get-entry-by-id (id entries)
+  "Return entry from ENTRIES by entry ID."
+  (cl-find-if (lambda (entry)
+                (equal id (guix-get-key-val entry 'id)))
+              entries))
+
+
+;;; Location of the packages
+
+(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-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)
+  "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
+`guix-directory'."
+  (cl-multiple-value-bind (path line col)
+      (split-string location ":")
+    (let ((file (expand-file-name path 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))))
+
+
+;;; Common definitions for buffer types
+
+(defvar-local guix-entries nil
+  "List of the currently displayed entries.
+Each element of the list is alist with entry info of the
+following form:
+
+  ((PARAM . VAL) ...)
+
+PARAM is a name of the entry parameter.
+VAL is a value of this parameter.")
+(put 'guix-entries 'permanent-local t)
+
+(defvar-local guix-search-type nil
+  "Type of the current search.")
+(put 'guix-search-type 'permanent-local t)
+
+(defvar-local guix-search-vals nil
+  "Values of the current search.")
+(put 'guix-search-vals 'permanent-local t)
+
+(defsubst guix-set-vars (entries search-type search-vals)
+  (setq guix-entries entries
+        guix-search-type search-type
+        guix-search-vals search-vals))
+
+(defmacro guix-define-buffer-type (buf-type entry-type &rest args)
+  "Define common stuff for BUF-TYPE buffers for displaying entries.
+
+ENTRY-TYPE is a type of displayed entries (see
+`guix-get-entries').
+
+In the text below TYPE means ENTRY-TYPE-BUF-TYPE.
+
+This macro defines `guix-TYPE-mode', a custom group, several user
+variables and the following functions:
+
+  - `guix-TYPE-get-params-for-receiving'
+  - `guix-TYPE-revert'
+  - `guix-TYPE-redisplay'
+  - `guix-TYPE-make-history-item'
+  - `guix-TYPE-set'
+  - `guix-TYPE-show'
+  - `guix-TYPE-get-show'
+
+The following stuff should be defined outside this macro:
+
+  - `guix-BUF-TYPE-mode' - parent mode for the defined mode.
+
+  - `guix-BUF-TYPE-insert-entries' - function for inserting
+  entries in the current buffer; it is called with 2 arguments:
+  entries of the form of `guix-entries' and ENTRY-TYPE.
+
+  - `guix-BUF-TYPE-get-displayed-params' - function returning a
+  list of parameters displayed in the current buffer; it is
+  called with ENTRY-TYPE as argument.
+
+  - `guix-TYPE-mode-initialize' (optional) - function for
+  additional mode settings; it is called without arguments.
+
+Remaining argument (ARGS) should have a form [KEYWORD VALUE] ...  The
+following keywords are available:
+
+  - `:required' - default value for the defined
+    `guix-TYPE-required-params' variable.
+
+  - `:history-size' - default value for the defined
+    `guix-TYPE-history-size' variable.
+
+  - `:revert' - default value for the defined
+    `guix-TYPE-revert-no-confirm' variable."
+  (let* ((entry-type-str (symbol-name entry-type))
+         (buf-type-str   (symbol-name buf-type))
+         (Entry-type-str (capitalize entry-type-str))
+         (Buf-type-str   (capitalize buf-type-str))
+         (entry-str      (concat entry-type-str " entries"))
+         (buf-str        (concat buf-type-str " buffer"))
+         (prefix         (concat "guix-" entry-type-str "-" buf-type-str))
+         (group          (intern prefix))
+         (mode-map-str   (concat prefix "-mode-map"))
+         (mode-map       (intern mode-map-str))
+         (parent-mode    (intern (concat "guix-" buf-type-str "-mode")))
+         (mode           (intern (concat prefix "-mode")))
+         (mode-init-fun  (intern (concat prefix "-mode-initialize")))
+         (buf-name-var   (intern (concat prefix "-buffer-name")))
+         (revert-var     (intern (concat prefix "-revert-no-confirm")))
+         (revert-fun     (intern (concat prefix "-revert")))
+         (redisplay-fun  (intern (concat prefix "-redisplay")))
+         (history-var    (intern (concat prefix "-history-size")))
+         (history-fun    (intern (concat prefix "-make-history-item")))
+         (params-var     (intern (concat prefix "-required-params")))
+         (params-fun     (intern (concat prefix "-get-params-for-receiving")))
+         (set-fun        (intern (concat prefix "-set")))
+         (show-fun       (intern (concat prefix "-show")))
+         (get-show-fun   (intern (concat prefix "-get-show")))
+         (revert-val     nil)
+         (history-val    20)
+         (params-val     '(id)))
+
+    ;; Process the keyword args.
+    (while (keywordp (car args))
+      (pcase (pop args)
+	(`:required     (setq params-val (pop args)))
+	(`:history-size (setq history-val (pop args)))
+	(`:revert       (setq revert-val (pop args)))
+	(_ (pop args))))
+
+    `(progn
+       (defgroup ,group nil
+         ,(concat Buf-type-str " buffer with " entry-str ".")
+         :prefix ,(concat prefix "-")
+         :group ',(intern (concat "guix-" buf-type-str)))
+
+       (defcustom ,buf-name-var ,(format "*Guix %s %s*"
+                                         Entry-type-str Buf-type-str)
+         ,(concat "Default name of the " buf-str " for displaying " entry-str ".")
+         :type 'string
+         :group ',group)
+
+       (defcustom ,history-var ,history-val
+         ,(concat "Maximum number of items saved in the history of the " buf-str ".\n"
+                  "If 0, the history is disabled.")
+         :type 'integer
+         :group ',group)
+
+       (defcustom ,revert-var ,revert-val
+         ,(concat "If non-nil, do not ask to confirm for reverting the " buf-str ".")
+         :type 'boolean
+         :group ',group)
+
+       (defvar ,params-var ',params-val
+         ,(concat "List of required " entry-type-str " parameters.\n\n"
+                  "Displayed parameters and parameters from this list are received\n"
+                  "for each " entry-type-str ".\n\n"
+                  "May be a special value `all', in which case all supported\n"
+                  "parameters are received (this may be very slow for a big number\n"
+                  "of entries).\n\n"
+                  "Do not remove `id' from this list as it is required for\n"
+                  "identifying an entry."))
+
+       (define-derived-mode ,mode ,parent-mode ,(concat "Guix-" Buf-type-str)
+         ,(concat "Major mode for displaying information about " entry-str ".\n\n"
+                  "\\{" mode-map-str "}")
+         (setq-local revert-buffer-function ',revert-fun)
+         (setq-local guix-history-size ,history-var)
+         (and (fboundp ',mode-init-fun) (,mode-init-fun)))
+
+       (let ((map ,mode-map))
+         (define-key map (kbd "l") 'guix-history-back)
+         (define-key map (kbd "r") 'guix-history-forward)
+         (define-key map (kbd "g") 'revert-buffer)
+         (define-key map (kbd "R") ',redisplay-fun)
+         (define-key map (kbd "C-c C-z") 'guix-switch-to-repl))
+
+       (defun ,params-fun ()
+         ,(concat "Return " entry-type-str " parameters that should be received.")
+         (unless (equal ,params-var 'all)
+           (cl-union ,params-var
+                     (,(intern (concat "guix-" buf-type-str "-get-displayed-params"))
+                      ',entry-type))))
+
+       (defun ,revert-fun (_ignore-auto noconfirm)
+         "Update information in the current buffer.
+The function is suitable for `revert-buffer-function'.
+See `revert-buffer' for the meaning of NOCONFIRM."
+         (when (or ,revert-var
+                   noconfirm
+                   (y-or-n-p "Update current information? "))
+           (let ((entries (guix-get-entries ',entry-type guix-search-type
+                                            guix-search-vals (,params-fun))))
+             (,set-fun entries guix-search-type guix-search-vals t))))
+
+       (defun ,redisplay-fun ()
+         "Redisplay current information.
+This function will not update the information, use
+\"\\[revert-buffer]\" if you want the full update."
+         (interactive)
+         (,show-fun guix-entries)
+         (guix-result-message guix-entries ',entry-type
+                              guix-search-type guix-search-vals))
+
+       (defun ,history-fun ()
+         "Make and return a history item for the current buffer."
+         (list (lambda (entries search-type search-vals)
+                 (,show-fun entries)
+                 (guix-set-vars entries search-type search-vals)
+                 (guix-result-message entries ',entry-type
+                                      search-type search-vals))
+               guix-entries guix-search-type guix-search-vals))
+
+       (defun ,set-fun (entries search-type search-vals &optional history-replace)
+         ,(concat "Set up the " buf-str " for displaying " entry-str ".\n\n"
+                  "Display ENTRIES, set variables and make history item.\n\n"
+                  "ENTRIES should have a form of `guix-entries'.\n\n"
+                  "See `guix-get-entries' for the meaning of SEARCH-TYPE and\n"
+                  "SEARCH-VALS.\n\n"
+                  "If HISTORY-REPLACE is non-nil, replace current history item,\n"
+                  "otherwise add the new one.")
+         (when entries
+           (let ((buf (if (eq major-mode ',mode)
+                          (current-buffer)
+                        (get-buffer-create ,buf-name-var))))
+             (with-current-buffer buf
+               (,show-fun entries)
+               (guix-set-vars entries search-type search-vals)
+               (funcall (if history-replace
+                            #'guix-history-replace
+                          #'guix-history-add)
+                        (,history-fun)))
+             (pop-to-buffer buf
+                            '((display-buffer-reuse-window
+                               display-buffer-same-window)))))
+         (guix-result-message entries ',entry-type
+                              search-type search-vals))
+
+       (defun ,show-fun (entries)
+         ,(concat "Display " entry-type-str " ENTRIES in the current " buf-str ".")
+         (let ((inhibit-read-only t))
+           (erase-buffer)
+           (,mode)
+           (,(intern (concat "guix-" buf-type-str "-insert-entries"))
+            entries ',entry-type)
+           (goto-char (point-min))))
+
+       (defun ,get-show-fun (search-type &rest search-vals)
+         ,(concat "Search for " entry-str " and show results in the " buf-str ".\n"
+                  "See `guix-get-entries' for the meaning of SEARCH-TYPE and\n"
+                  "SEARCH-VALS.")
+         (let ((entries (guix-get-entries ',entry-type search-type
+                                          search-vals (,params-fun))))
+           (,set-fun entries search-type search-vals))))))
+
+(put 'guix-define-buffer-type 'lisp-indent-function 'defun)
+
+
+;;; Messages
+
+(defvar guix-messages
+  '((package
+     (id
+      (0 "Packages not found.")
+      (1 "")
+      (many "%d packages." count))
+     (name
+      (0 "The package '%s' not found." val)
+      (1 "A single package with name '%s'." val)
+      (many "%d packages with '%s' name." count val))
+     (regexp
+      (0 "No packages matching '%s'." val)
+      (1 "A single package matching '%s'." val)
+      (many "%d packages matching '%s'." count val))
+     (all-available
+      (0 "No packages are available for some reason.")
+      (1 "A single available package (that's strange).")
+      (many "%d available packages." count))
+     (newest-available
+      (0 "No packages are available for some reason.")
+      (1 "A single newest available package (that's strange).")
+      (many "%d newest available packages." count))
+     (installed
+      (0 "No installed packages.")
+      (1 "A single installed package.")
+      (many "%d installed packages." count))
+     (obsolete
+      (0 "No obsolete packages.")
+      (1 "A single obsolete package.")
+      (many "%d obsolete packages." count))
+     (generation
+      (0 "No packages installed in generation %d." val)
+      (1 "A single package installed in generation %d." val)
+      (many "%d packages installed in generation %d." count val)))
+    (generation
+     (id
+      (0 "Generations not found.")
+      (1 "")
+      (many "%d generations." count))
+     (last
+      (0 "No available generations.")
+      (1 "The last generation.")
+      (many "%d last generations." count))
+     (all
+      (0 "No available generations.")
+      (1 "A single available generation.")
+      (many "%d available generations." count)))))
+
+(defun guix-result-message (entries entry-type search-type search-vals)
+  "Display an appropriate message after displaying ENTRIES."
+  (let* ((val (car search-vals))
+         (count (length entries))
+         (count-key (if (> count 1) 'many count))
+         (msg-spec (guix-get-key-val guix-messages
+                                     entry-type search-type count-key))
+         (format (car msg-spec))
+         (args (cdr msg-spec)))
+    (mapc (lambda (subst)
+            (setq args (cl-substitute (car subst) (cdr subst) args)))
+          (list (cons count 'count)
+                (cons val 'val)))
+    (apply #'message format args)))
+
+
+;;; Getting info about packages and generations
+
+(defun guix-get-entries (entry-type search-type search-vals &optional params)
+  "Search for entries of ENTRY-TYPE.
+
+Call an appropriate scheme function and return a list of the
+form of `guix-entries'.
+
+ENTRY-TYPE should be one of the following symbols: `package' or
+`generation'.
+
+SEARCH-TYPE may be one of the following symbols:
+
+- If ENTRY-TYPE is `package': `id', `name', `regexp',
+  `all-available', `newest-available', `installed', `obsolete',
+  `generation'.
+
+- If ENTRY-TYPE is `generation': `id', `last', `all'.
+
+PARAMS is a list of parameters for receiving.  If nil, get
+information with all available parameters."
+  (guix-eval-read (guix-make-guile-expression
+                   'get-entries
+                   guix-current-profile params
+                   entry-type search-type search-vals)))
+
+
+;;; Actions on packages and generations
+
+(defcustom guix-operation-confirm t
+  "If nil, do not prompt to confirm an operation."
+  :type 'boolean
+  :group 'guix)
+
+(defcustom guix-use-substitutes t
+  "If non-nil, use substitutes for the Guix packages."
+  :type 'boolean
+  :group 'guix)
+
+(defvar guix-dry-run nil
+  "If non-nil, do not perform the real actions, just simulate.")
+
+(defvar guix-temp-buffer-name " *Guix temp*"
+  "Name of a buffer used for displaying info before executing operation.")
+
+(defun guix-process-package-actions (&rest actions)
+  "Process package ACTIONS.
+Each action is a list of the form:
+
+  (ACTION-TYPE PACKAGE-SPEC ...)
+
+ACTION-TYPE is one of the following symbols: `install',
+`upgrade', `remove'/`delete'.
+PACKAGE-SPEC should have the following form: (ID [OUTPUT] ...)."
+  (let (install upgrade remove)
+    (mapc (lambda (action)
+            (let ((action-type (car action))
+                  (specs (cdr action)))
+              (cl-case action-type
+                (install (setq install (append install specs)))
+                (upgrade (setq upgrade (append upgrade specs)))
+                ((remove delete) (setq remove (append remove specs))))))
+          actions)
+    (when (guix-continue-package-operation-p
+           :install install :upgrade upgrade :remove remove)
+      (guix-eval-in-repl
+       (guix-make-guile-expression
+        'process-package-actions guix-current-profile
+        :install install :upgrade upgrade :remove remove
+        :use-substitutes? (or guix-use-substitutes 'f)
+        :dry-run? (or guix-dry-run 'f))))))
+
+(cl-defun guix-continue-package-operation-p (&key install upgrade remove)
+  "Return non-nil if a package operation should be continued.
+Ask a user if needed (see `guix-operation-confirm').
+INSTALL, UPGRADE, REMOVE are 'package action specifications'.
+See `guix-process-package-actions' for details."
+  (or (null guix-operation-confirm)
+      (let* ((entries (guix-get-entries
+                       'package 'id
+                       (list (append (mapcar #'car install)
+                                     (mapcar #'car upgrade)
+                                     (mapcar #'car remove)))
+                       '(id name version location)))
+             (install-strings (guix-get-package-strings install entries))
+             (upgrade-strings (guix-get-package-strings upgrade entries))
+             (remove-strings  (guix-get-package-strings remove entries)))
+        (if (or install-strings upgrade-strings remove-strings)
+            (let ((buf (get-buffer-create guix-temp-buffer-name)))
+              (with-current-buffer buf
+                (setq-local cursor-type nil)
+                (setq buffer-read-only nil)
+                (erase-buffer)
+                (guix-insert-package-strings install-strings "install")
+                (guix-insert-package-strings upgrade-strings "upgrade")
+                (guix-insert-package-strings remove-strings "remove")
+                (let ((win (temp-buffer-window-show
+                            buf
+                            '((display-buffer-reuse-window
+                               display-buffer-at-bottom)
+                              (window-height . fit-window-to-buffer)))))
+                  (prog1 (y-or-n-p "Continue operation? ")
+                    (quit-window nil win)))))
+          (message "Nothing to be done.  If the REPL was restarted, information is not up-to-date.")
+          nil))))
+
+(defun guix-get-package-strings (specs entries)
+  "Return short package descriptions for performing package actions.
+See `guix-process-package-actions' for the meaning of SPECS.
+ENTRIES is a list of package entries to get info about packages."
+  (delq nil
+        (mapcar
+         (lambda (spec)
+           (let* ((id (car spec))
+                  (outputs (cdr spec))
+                  (entry (guix-get-entry-by-id id entries)))
+             (when entry
+               (let ((location (guix-get-key-val entry 'location)))
+                 (concat (guix-get-full-name entry)
+                         (when outputs
+                           (concat ":"
+                                   (mapconcat #'identity outputs ",")))
+                         (when location
+                           (concat "\t(" location ")")))))))
+         specs)))
+
+(defun guix-insert-package-strings (strings action)
+  "Insert information STRINGS at point for performing package ACTION."
+  (when strings
+    (insert "Package(s) to " (guix-get-string action 'bold) ":\n")
+    (mapc (lambda (str)
+            (insert "  " str "\n"))
+          strings)
+    (insert "\n")))
+
+(provide 'guix-base)
+
+;;; guix-base.el ends here

emacs/guix-helper.scm.in

@@ -0,0 +1,64 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 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 License as published by
+;;; the Free Software Foundation; either version 3 of the License, 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 License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This is an auxiliary file for the Emacs UI.  It is used to add Guix
+;; directories to path variables and to load the main code.
+
+;;; Code:
+
+(use-modules (ice-9 regex)
+             (srfi srfi-26))
+
+(define %guix-dir)
+
+;; The code is taken from ‘guix’ executable script
+(define (set-paths!)
+  (define-syntax-rule (push! elt v) (set! v (cons elt v)))
+
+  (define config-lookup
+    (let ((config '(("prefix"         . "@prefix@")
+                    ("guilemoduledir" . "@guilemoduledir@")))
+          (var-ref-regexp (make-regexp "\\$\\{([a-z]+)\\}")))
+      (define (expand-var-ref match)
+        (lookup (match:substring match 1)))
+      (define (expand str)
+        (regexp-substitute/global #f var-ref-regexp str
+                                  'pre expand-var-ref 'post))
+      (define (lookup name)
+        (expand (assoc-ref config name)))
+      lookup))
+
+  (let ((module-dir (config-lookup "guilemoduledir"))
+        (updates-dir (and=> (or (getenv "XDG_CONFIG_HOME")
+                                (and=> (getenv "HOME")
+                                       (cut string-append <> "/.config")))
+                            (cut string-append <> "/guix/latest"))))
+    (push! module-dir %load-compiled-path)
+    (if (and updates-dir (file-exists? updates-dir))
+        (begin
+          (set! %guix-dir updates-dir)
+          (push! updates-dir %load-path)
+          (push! updates-dir %load-compiled-path))
+        (set! %guix-dir module-dir))))
+
+(set-paths!)
+
+(load-from-path "guix-main")
+

emacs/guix-history.el

@@ -0,0 +1,92 @@
+;;; guix-history.el --- History of buffer information
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides support for history of buffers similar to the
+;; history of a `help-mode' buffer.
+
+;;; Code:
+
+(require 'cl-macs)
+
+(defvar-local guix-history-stack-item nil
+  "Current item of the history.
+A list of the form (FUNCTION [ARGS ...]).
+The item is used by calling (apply FUNCTION ARGS).")
+(put 'guix-history-stack-item 'permanent-local t)
+
+(defvar-local guix-history-back-stack nil
+  "Stack (list) of visited items.
+Each element of the list has a form of `guix-history-stack-item'.")
+(put 'guix-history-back-stack 'permanent-local t)
+
+(defvar-local guix-history-forward-stack nil
+  "Stack (list) of items visited with `guix-history-back'.
+Each element of the list has a form of `guix-history-stack-item'.")
+(put 'guix-history-forward-stack 'permanent-local t)
+
+(defvar guix-history-size 0
+  "Maximum number of items saved in history.
+If 0, the history is disabled.")
+
+(defun guix-history-add (item)
+  "Add ITEM to history."
+  (and guix-history-stack-item
+       (push guix-history-stack-item guix-history-back-stack))
+  (setq guix-history-forward-stack nil
+        guix-history-stack-item item)
+  (when (>= (length guix-history-back-stack)
+            guix-history-size)
+    (setq guix-history-back-stack
+          (cl-loop for elt in guix-history-back-stack
+                   for i from 1 to guix-history-size
+                   collect elt))))
+
+(defun guix-history-replace (item)
+  "Replace current item in history with ITEM."
+  (setq guix-history-stack-item item))
+
+(defun guix-history-goto (item)
+  "Go to the ITEM of history.
+ITEM should have the form of `guix-history-stack-item'."
+  (or (listp item)
+      (error "Wrong value of history element"))
+  (setq guix-history-stack-item item)
+  (apply (car item) (cdr item)))
+
+(defun guix-history-back ()
+  "Go back to the previous element of history in the current buffer."
+  (interactive)
+  (or guix-history-back-stack
+      (user-error "No previous element in history"))
+  (push guix-history-stack-item guix-history-forward-stack)
+  (guix-history-goto (pop guix-history-back-stack)))
+
+(defun guix-history-forward ()
+  "Go forward to the next element of history in the current buffer."
+  (interactive)
+  (or guix-history-forward-stack
+      (user-error "No next element in history"))
+  (push guix-history-stack-item guix-history-back-stack)
+  (guix-history-goto (pop guix-history-forward-stack)))
+
+(provide 'guix-history)
+
+;;; guix-history.el ends here

emacs/guix-info.el

@@ -0,0 +1,556 @@
+;;; guix-info.el --- Info buffers for displaying entries
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides a help-like buffer for displaying information
+;; about Guix packages and generations.
+
+;;; Code:
+
+(require 'guix-history)
+(require 'guix-base)
+(require 'guix-utils)
+
+(defgroup guix-info nil
+  "General settings for info buffers."
+  :prefix "guix-info-"
+  :group 'guix)
+
+(defface guix-info-param-title
+  '((t :inherit font-lock-type-face))
+  "Face used for titles of parameters."
+  :group 'guix-info)
+
+(defface guix-info-file-path
+  '((t :inherit link))
+  "Face used for file paths."
+  :group 'guix-info)
+
+(defface guix-info-url
+  '((t :inherit link))
+  "Face used for URLs."
+  :group 'guix-info)
+
+(defface guix-info-time
+  '((t :inherit font-lock-constant-face))
+  "Face used for timestamps."
+  :group 'guix-info)
+
+(defface guix-info-action-button
+  '((((type x w32 ns) (class color))
+     :box (:line-width 2 :style released-button)
+     :background "lightgrey" :foreground "black")
+    (t :inherit button))
+  "Face used for action buttons."
+  :group 'guix-info)
+
+(defface guix-info-action-button-mouse
+  '((((type x w32 ns) (class color))
+     :box (:line-width 2 :style released-button)
+     :background "grey90" :foreground "black")
+    (t :inherit highlight))
+  "Mouse face used for action buttons."
+  :group 'guix-info)
+
+(defcustom guix-info-ignore-empty-vals nil
+  "If non-nil, do not display parameters with nil values."
+  :type 'boolean
+  :group 'guix-info)
+
+(defvar guix-info-param-title-format "%-18s: "
+  "String used to format a title of a parameter.
+It should be a '%s'-sequence.  After inserting a title formatted
+with this string, a value of the parameter is inserted.
+This string is used by `guix-info-insert-title-default'.")
+
+(defvar guix-info-multiline-prefix (make-string 20 ?\s)
+  "String used to format multi-line parameter values.
+If a value occupies more than one line, this string is inserted
+in the beginning of each line after the first one.
+This string is used by `guix-info-insert-val-default'.")
+
+(defvar guix-info-indent 2
+  "Number of spaces used to indent various parts of inserted text.")
+
+(defvar guix-info-fill-column 60
+  "Column used for filling (word wrapping) parameters with long lines.
+If a value is not multi-line and it occupies more than this
+number of characters, it will be split into several lines.")
+
+(defvar guix-info-delimiter "\n\f\n"
+  "String used to separate entries.")
+
+(defvar guix-info-insert-methods
+  '((package
+     (name              guix-package-info-name)
+     (version           guix-package-info-version)
+     (license           guix-package-info-license)
+     (synopsis          guix-package-info-synopsis)
+     (description       guix-package-info-insert-description
+                        guix-info-insert-title-simple)
+     (outputs           guix-package-info-insert-outputs
+                        guix-info-insert-title-simple)
+     (home-url          guix-info-insert-url)
+     (inputs            guix-package-info-insert-inputs)
+     (native-inputs     guix-package-info-insert-native-inputs)
+     (propagated-inputs guix-package-info-insert-propagated-inputs)
+     (location          guix-package-info-insert-location))
+    (installed
+     (path              guix-package-info-insert-output-path
+                        guix-info-insert-title-simple)
+     (dependencies      guix-package-info-insert-output-dependencies
+                        guix-info-insert-title-simple))
+    (generation
+     (number            guix-generation-info-insert-number)
+     (path              guix-info-insert-file-path)
+     (time              guix-info-insert-time)))
+  "Methods for inserting parameter values.
+Each element of the list should have a form:
+
+  (ENTRY-TYPE . ((PARAM INSERT-VALUE [INSERT-TITLE]) ...))
+
+INSERT-VALUE may be either nil, a face name or a function.  If it
+is nil or a face, `guix-info-insert-val-default' function is
+called with parameter value and INSERT-VALUE as arguments.  If it
+is a function, this function is called with parameter value and
+entry info (alist of parameters and their values) as arguments.
+
+INSERT-TITLE may be either nil, a face name or a function.  If it
+is nil or a face, `guix-info-insert-title-default' function is
+called with parameter title and INSERT-TITLE as arguments.  If it
+is a function, this function is called with parameter title as
+argument.")
+
+(defvar guix-info-displayed-params
+  '((package name version synopsis outputs location home-url
+             license inputs native-inputs propagated-inputs description)
+    (installed path dependencies)
+    (generation number prev-number time path))
+  "List of displayed entry parameters.
+Each element of the list should have a form:
+
+  (ENTRY-TYPE . (PARAM ...))
+
+The order of displayed parameters is the same as in this list.")
+
+(defun guix-info-get-insert-methods (entry-type param)
+  "Return list of insert methods for parameter PARAM of ENTRY-TYPE.
+See `guix-info-insert-methods' for details."
+  (guix-get-key-val guix-info-insert-methods
+                    entry-type param))
+
+(defun guix-info-get-displayed-params (entry-type)
+  "Return parameters of ENTRY-TYPE that should be displayed."
+  (guix-get-key-val guix-info-displayed-params
+                    entry-type))
+
+(defun guix-info-get-indent (&optional level)
+  "Return `guix-info-indent' \"multiplied\" by LEVEL spaces.
+LEVEL is 1 by default."
+  (make-string (* guix-info-indent (or level 1)) ?\s))
+
+(defun guix-info-insert-indent (&optional level)
+  "Insert `guix-info-indent' spaces LEVEL times (1 by default)."
+  (insert (guix-info-get-indent level)))
+
+(defun guix-info-insert-entries (entries entry-type)
+  "Display ENTRIES of ENTRY-TYPE in the current info buffer.
+ENTRIES should have a form of `guix-entries'."
+  (guix-mapinsert (lambda (entry)
+                    (guix-info-insert-entry entry entry-type))
+                  entries
+                  guix-info-delimiter))
+
+(defun guix-info-insert-entry (entry entry-type &optional indent-level)
+  "Insert ENTRY of ENTRY-TYPE into the current info buffer.
+If INDENT-LEVEL is non-nil, indent displayed information by this
+number of `guix-info-indent' spaces."
+  (let ((region-beg (point)))
+    (mapc (lambda (param)
+            (guix-info-insert-param param entry entry-type))
+          (guix-info-get-displayed-params entry-type))
+    (when indent-level
+      (indent-rigidly region-beg (point)
+                      (* indent-level guix-info-indent)))))
+
+(defun guix-info-insert-param (param entry entry-type)
+  "Insert title and value of a PARAM at point.
+ENTRY is alist with parameters and their values.
+ENTRY-TYPE is a type of ENTRY."
+  (let ((val (guix-get-key-val entry param)))
+    (unless (and guix-info-ignore-empty-vals (null val))
+      (let* ((title          (guix-get-param-title entry-type param))
+             (insert-methods (guix-info-get-insert-methods entry-type param))
+             (val-method     (car insert-methods))
+             (title-method   (cadr insert-methods)))
+        (guix-info-method-funcall title title-method
+                                  #'guix-info-insert-title-default)
+        (guix-info-method-funcall val val-method
+                                  #'guix-info-insert-val-default
+                                  entry)
+        (insert "\n")))))
+
+(defun guix-info-method-funcall (val method default-fun &rest args)
+  "Call METHOD or DEFAULT-FUN.
+
+If METHOD is a function and VAL is non-nil, call this
+function by applying it to VAL and ARGS.
+
+If METHOD is a face, propertize inserted VAL with this face."
+  (cond ((or (null method)
+             (facep method))
+         (funcall default-fun val method))
+        ((functionp method)
+         (apply method val args))
+        (t (error "Unknown method '%S'" method))))
+
+(defun guix-info-insert-title-default (title &optional face format)
+  "Insert TITLE formatted with `guix-info-param-title-format' at point."
+  (guix-format-insert title
+                      (or face 'guix-info-param-title)
+                      (or format guix-info-param-title-format)))
+
+(defun guix-info-insert-title-simple (title &optional face)
+  "Insert TITLE at point."
+  (guix-info-insert-title-default title face "%s:"))
+
+(defun guix-info-insert-val-default (val &optional face)
+  "Format and insert parameter value VAL at point.
+
+This function is intended to be called after
+`guix-info-insert-title-default'.
+
+If VAL is a one-line string longer than `guix-info-fill-column',
+split it into several short lines.  See also
+`guix-info-multiline-prefix'.
+
+If FACE is non-nil, propertize inserted line(s) with this FACE."
+  (guix-split-insert val face
+                     guix-info-fill-column
+                     (concat "\n" guix-info-multiline-prefix)))
+
+(defun guix-info-insert-val-simple (val &optional face-or-fun)
+  "Format and insert parameter value VAL at point.
+
+This function is intended to be called after
+`guix-info-insert-title-simple'.
+
+If VAL is a one-line string longer than `guix-info-fill-column',
+split it into several short lines and indent each line with
+`guix-info-indent' spaces.
+
+If FACE-OR-FUN is a face, propertize inserted line(s) with this FACE.
+
+If FACE-OR-FUN is a function, call it with VAL as argument.  If
+VAL is a list, call the function on each element of this list."
+  (if (null val)
+      (progn (guix-info-insert-indent)
+             (guix-format-insert nil))
+    (let ((prefix (concat "\n" (guix-info-get-indent))))
+      (insert prefix)
+      (if (functionp face-or-fun)
+          (guix-mapinsert face-or-fun
+                          (if (listp val) val (list val))
+                          prefix)
+        (guix-split-insert val face-or-fun
+                           guix-info-fill-column prefix)))))
+
+(defun guix-info-insert-action-button (label action &optional message
+                                             &rest properties)
+  "Make action button with LABEL and insert it at point.
+For the meaning of ACTION, MESSAGE and PROPERTIES, see
+`guix-insert-button'."
+  (apply #'guix-insert-button
+         label 'guix-info-action-button action message
+         'mouse-face 'guix-info-action-button-mouse
+         properties))
+
+(defun guix-info-insert-file-path (path &optional _)
+  "Make button from file PATH and insert it at point."
+  (guix-insert-button
+   path 'guix-info-file-path
+   (lambda (btn) (find-file (button-label btn)))
+   "Find file"))
+
+(defun guix-info-insert-url (url &optional _)
+  "Make button from URL and insert it at point."
+  (guix-insert-button
+   url 'guix-info-url
+   (lambda (btn) (browse-url (button-label btn)))
+   "Browse URL"))
+
+(defun guix-info-insert-time (seconds &optional _)
+  "Insert formatted time string using SECONDS at point."
+  (guix-info-insert-val-default (guix-get-time-string seconds)
+                                'guix-info-time))
+
+
+(defvar guix-info-mode-map
+  (let ((map (make-sparse-keymap)))
+    (set-keymap-parent
+     map (make-composed-keymap button-buffer-map
+                               special-mode-map))
+    map)
+  "Parent keymap for info buffers.")
+
+(define-derived-mode guix-info-mode special-mode "Guix-Info"
+  "Parent mode for displaying information in info buffers.")
+
+
+;;; Displaying packages
+
+(guix-define-buffer-type info package
+  :required (id installed non-unique))
+
+(defface guix-package-info-name
+  '((t :inherit font-lock-keyword-face))
+  "Face used for a name of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-version
+  '((t :inherit font-lock-builtin-face))
+  "Face used for a version of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-synopsis
+  '((t :inherit font-lock-doc-face))
+  "Face used for a synopsis of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-description
+  '((t))
+  "Face used for a description of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-license
+  '((t :inherit font-lock-string-face))
+  "Face used for a license of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-location
+  '((t :inherit link))
+  "Face used for a location of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-installed-outputs
+  '((default :weight bold)
+    (((class color) (min-colors 88) (background light))
+     :foreground "ForestGreen")
+    (((class color) (min-colors 88) (background dark))
+     :foreground "PaleGreen")
+    (((class color) (min-colors 8))
+     :foreground "green")
+    (t :underline t))
+  "Face used for installed outputs of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-uninstalled-outputs
+  '((t :weight bold))
+  "Face used for uninstalled outputs of a package."
+  :group 'guix-package-info)
+
+(defface guix-package-info-obsolete
+  '((t :inherit error))
+  "Face used if a package is obsolete."
+  :group 'guix-package-info)
+
+(defun guix-package-info-insert-description (desc &optional _)
+  "Insert description DESC at point."
+  (guix-info-insert-val-simple desc 'guix-package-info-description))
+
+(defun guix-package-info-insert-location (location &optional _)
+  "Make button from file LOCATION and insert it at point."
+  (guix-insert-button
+   location 'guix-package-info-location
+   (lambda (btn) (guix-find-location (button-label btn)))
+   "Find location of this package"))
+
+(defmacro guix-package-info-define-insert-inputs (&optional type)
+  "Define a face and a function for inserting package inputs.
+TYPE is a type of inputs.
+Function name is `guix-package-info-insert-TYPE-inputs'.
+Face name is `guix-package-info-TYPE-inputs'."
+  (let* ((type-str (symbol-name type))
+         (type-name (and type (concat type-str "-")))
+         (type-desc (and type (concat type-str " ")))
+         (face (intern (concat "guix-package-info-" type-name "inputs")))
+         (fun  (intern (concat "guix-package-info-insert-" type-name "inputs"))))
+    `(progn
+       (defface ,face
+         '((t :inherit button))
+         ,(concat "Face used for " type-desc "inputs of a package.")
+         :group 'guix-package-info)
+
+       (defun ,fun (inputs &optional _)
+         ,(concat "Make buttons from " type-desc "INPUTS and insert them at point.")
+         (guix-package-info-insert-full-names inputs ',face)))))
+
+(guix-package-info-define-insert-inputs)
+(guix-package-info-define-insert-inputs native)
+(guix-package-info-define-insert-inputs propagated)
+
+(defun guix-package-info-insert-full-names (names face)
+  "Make buttons from package NAMES and insert them at point.
+NAMES is a list of strings.
+Propertize buttons with FACE."
+  (if names
+      (guix-info-insert-val-default
+       (with-temp-buffer
+         (guix-mapinsert (lambda (name)
+                           (guix-package-info-insert-full-name
+                            name face))
+                         names
+                         guix-list-separator)
+         (buffer-substring (point-min) (point-max))))
+    (guix-format-insert nil)))
+
+(defun guix-package-info-insert-full-name (name face)
+  "Make button and insert package NAME at point.
+Propertize package button with FACE."
+  (guix-insert-button
+   name face
+   (lambda (btn)
+     (guix-package-info-get-show 'name (button-label btn)))
+   "Describe this package"))
+
+
+;;; Inserting outputs and installed parameters
+
+(defvar guix-package-info-output-format "%-10s"
+  "String used to format output names of the packages.
+It should be a '%s'-sequence.  After inserting an output name
+formatted with this string, an action button is inserted.")
+
+(defvar guix-package-info-obsolete-string "(This package is obsolete)"
+  "String used if a package is obsolete.")
+
+(defun guix-package-info-insert-outputs (outputs entry)
+  "Insert OUTPUTS from package ENTRY at point."
+  (and (guix-get-key-val entry 'obsolete)
+       (guix-package-info-insert-obsolete-text))
+  (and (guix-get-key-val entry 'non-unique)
+       (guix-get-key-val entry 'installed)
+       (guix-package-info-insert-non-unique-text
+        (guix-get-full-name entry)))
+  (insert "\n")
+  (mapc (lambda (output)
+          (guix-package-info-insert-output output entry))
+        outputs))
+
+(defun guix-package-info-insert-obsolete-text ()
+  "Insert a message about obsolete package at point."
+  (guix-info-insert-indent)
+  (guix-format-insert guix-package-info-obsolete-string
+                      'guix-package-info-obsolete))
+
+(defun guix-package-info-insert-non-unique-text (full-name)
+  "Insert a message about non-unique package with FULL-NAME at point."
+  (insert "\n")
+  (guix-info-insert-indent)
+  (insert "Installed outputs are displayed for a non-unique ")
+  (guix-package-info-insert-full-name full-name
+                                      'guix-package-info-inputs)
+  (insert " package."))
+
+(defun guix-package-info-insert-output (output entry)
+  "Insert OUTPUT at point.
+Make some fancy text with buttons and additional stuff if the
+current OUTPUT is installed (if there is such output in
+`installed' parameter of a package ENTRY)."
+  (let* ((installed (guix-get-key-val entry 'installed))
+         (obsolete  (guix-get-key-val entry 'obsolete))
+         (installed-entry (cl-find-if
+                           (lambda (entry)
+                             (string= (guix-get-key-val entry 'output)
+                                      output))
+                           installed))
+         (action-type (if installed-entry 'delete 'install)))
+    (guix-info-insert-indent)
+    (guix-format-insert output
+                        (if installed-entry
+                            'guix-package-info-installed-outputs
+                          'guix-package-info-uninstalled-outputs)
+                        guix-package-info-output-format)
+    (guix-package-info-insert-action-button action-type entry output)
+    (when obsolete
+      (guix-info-insert-indent)
+      (guix-package-info-insert-action-button 'upgrade entry output))
+    (insert "\n")
+    (when installed-entry
+      (guix-info-insert-entry installed-entry 'installed 2))))
+
+(defun guix-package-info-insert-action-button (type entry output)
+  "Insert button to process an action on a package OUTPUT at point.
+TYPE is one of the following symbols: `install', `delete', `upgrade'.
+ENTRY is an alist with package info."
+  (let ((type-str (capitalize (symbol-name type)))
+        (full-name (guix-get-full-name entry output)))
+    (guix-info-insert-action-button
+     type-str
+     (lambda (btn)
+       (guix-process-package-actions
+        (list (button-get btn 'action-type)
+              (list (button-get btn 'id)
+                    (button-get btn 'output)))))
+     (concat type-str " '" full-name "'")
+     'action-type type
+     'id (guix-get-key-val entry 'id)
+     'output output)))
+
+(defun guix-package-info-insert-output-path (path &optional _)
+  "Insert PATH of the installed output."
+  (guix-info-insert-val-simple path #'guix-info-insert-file-path))
+
+(defun guix-package-info-insert-output-dependencies (deps &optional _)
+  "Insert dependencies DEPS of the installed output."
+  (guix-info-insert-val-simple deps #'guix-info-insert-file-path))
+
+
+;;; Displaying generations
+
+(guix-define-buffer-type info generation)
+
+(defface guix-generation-info-number
+  '((t :inherit font-lock-keyword-face))
+  "Face used for a number of a generation."
+  :group 'guix-generation-info)
+
+(declare-function guix-package-list-get-show "guix-list" t t)
+
+(defun guix-generation-info-insert-number (number &optional _)
+  "Insert generation NUMBER and action buttons."
+  (guix-info-insert-val-default number 'guix-generation-info-number)
+  (guix-info-insert-indent)
+  (guix-info-insert-action-button
+   "Packages"
+   (lambda (btn)
+     (guix-package-list-get-show 'generation
+                                 (button-get btn 'number)))
+   "Show installed packages for this generation"
+   'number number)
+  (guix-info-insert-indent)
+  (guix-info-insert-action-button
+   "Delete"
+   (lambda (btn) (error "Sorry, not implemented yet"))
+   "Delete this generation"))
+
+(provide 'guix-info)
+
+;;; guix-info.el ends here

emacs/guix-init.el.in

@@ -0,0 +1,14 @@
+(require 'guix-autoloads)
+
+(defvar guix-load-path
+  (replace-regexp-in-string "${prefix}" "@prefix@" "@emacsuidir@")
+  "Directory with scheme files for \"guix.el\" package.")
+
+(defvar guix-default-profile
+  (concat (or (getenv "NIX_STATE_DIR") "@guix_localstatedir@/guix")
+          "/profiles/per-user/"
+          (getenv "USER")
+          "/guix-profile")
+  "Default Guix profile.")
+
+(provide 'guix-init)

emacs/guix-list.el

@@ -0,0 +1,586 @@
+;;; guix-list.el --- List buffers for displaying entries   -*- lexical-binding: t -*-
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides a list-like buffer for displaying information
+;; about Guix packages and generations.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'tabulated-list)
+(require 'guix-info)
+(require 'guix-history)
+(require 'guix-base)
+(require 'guix-utils)
+
+(defgroup guix-list nil
+  "General settings for list buffers."
+  :prefix "guix-list-"
+  :group 'guix)
+
+(defface guix-list-file-path
+  '((t :inherit guix-info-file-path))
+  "Face used for file paths."
+  :group 'guix-list)
+
+(defcustom guix-list-describe-warning-count 10
+  "The maximum number of entries for describing without a warning.
+If a user wants to describe more than this number of marked
+entries, he will be prompted for confirmation."
+  :type 'integer
+  :group 'guix-list)
+
+(defvar guix-list-column-format
+  `((package
+     (name 20 t)
+     (version 10 nil)
+     (outputs 13 t)
+     (installed 13 t)
+     (synopsis 30 nil))
+    (generation
+     (number 5
+             ,(lambda (a b) (guix-list-sort-numerically 0 a b))
+             :right-align t)
+     (time 20 t)
+     (path 30 t)))
+  "Columns displayed in list buffers.
+Each element of the list has a form:
+
+  (ENTRY-TYPE . ((PARAM WIDTH SORT . PROPS) ...))
+
+PARAM is the name of an entry parameter of ENTRY-TYPE.  For the
+meaning of WIDTH, SORT and PROPS, see `tabulated-list-format'.")
+
+(defvar guix-list-column-titles
+  '((generation
+     (number . "N.")))
+  "Column titles for list buffers.
+Has the same structure as `guix-param-titles', but titles from
+this list have a priority.")
+
+(defvar guix-list-column-value-methods
+  '((package
+     (name        . guix-package-list-get-name)
+     (synopsis    . guix-list-get-one-line)
+     (description . guix-list-get-one-line)
+     (installed   . guix-package-list-get-installed-outputs))
+    (generation
+     (time . guix-list-get-time)
+     (path . guix-list-get-file-path)))
+  "Methods for inserting parameter values in columns.
+Each element of the list has a form:
+
+  (ENTRY-TYPE . ((PARAM . FUN) ...))
+
+PARAM is the name of an entry parameter of ENTRY-TYPE.
+
+FUN is a function returning a value that will be inserted.  The
+function is called with 2 arguments: the first one is the value
+of the parameter; the second argument is an entry info (alist of
+parameters and their values).")
+
+(defun guix-list-get-param-title (entry-type param)
+  "Return title of an ENTRY-TYPE entry parameter PARAM."
+  (or (guix-get-key-val guix-list-column-titles
+                        entry-type param)
+      (guix-get-param-title entry-type param)))
+
+(defun guix-list-get-column-format (entry-type)
+  "Return column format for ENTRY-TYPE."
+  (guix-get-key-val guix-list-column-format entry-type))
+
+(defun guix-list-get-displayed-params (entry-type)
+  "Return list of parameters of ENTRY-TYPE that should be displayed."
+  (mapcar #'car
+          (guix-list-get-column-format entry-type)))
+
+(defun guix-list-get-sort-key (entry-type param &optional invert)
+  "Return suitable sort key for `tabulated-list-sort-key'.
+Define column title by ENTRY-TYPE and PARAM.  If INVERT is
+non-nil, invert the sort."
+  (when (memq param (guix-list-get-displayed-params entry-type))
+    (cons (guix-list-get-param-title entry-type param) invert)))
+
+(defun guix-list-sort-numerically (column a b)
+  "Compare COLUMN of tabulated entries A and B numerically.
+It is a sort predicate for `tabulated-list-format'.
+Return non-nil, if B is bigger than A."
+  (cl-flet ((num (entry)
+              (string-to-number (aref (cadr entry) column))))
+    (> (num b) (num a))))
+
+(defun guix-list-make-tabulated-vector (entry-type fun)
+  "Call FUN on each column specification for ENTRY-TYPE.
+
+FUN is called with 2 argument: parameter name and column
+specification (see `guix-list-column-format').
+
+Return a vector made of values of FUN calls."
+  (apply #'vector
+         (mapcar (lambda (col-spec)
+                   (funcall fun (car col-spec) (cdr col-spec)))
+                 (guix-list-get-column-format entry-type))))
+
+(defun guix-list-get-list-format (entry-type)
+  "Return ENTRY-TYPE list specification for `tabulated-list-format'."
+  (guix-list-make-tabulated-vector
+   entry-type
+   (lambda (param spec)
+     (cons (guix-list-get-param-title entry-type param)
+           spec))))
+
+(defun guix-list-insert-entries (entries entry-type)
+  "Display ENTRIES of ENTRY-TYPE in the current list buffer.
+ENTRIES should have a form of `guix-entries'."
+  (setq tabulated-list-entries
+        (guix-list-get-tabulated-entries entries entry-type))
+  (tabulated-list-print))
+
+(defun guix-list-get-tabulated-entries (entries entry-type)
+  "Return list of values of ENTRY-TYPE for `tabulated-list-entries'.
+Values are taken from ENTRIES which should have the form of
+`guix-entries'."
+  (mapcar (lambda (entry)
+            (list (guix-get-key-val entry 'id)
+                  (guix-list-get-tabulated-entry entry entry-type)))
+          entries))
+
+(defun guix-list-get-tabulated-entry (entry entry-type)
+  "Return array of values for `tabulated-list-entries'.
+Parameters are taken from ENTRY of ENTRY-TYPE."
+  (guix-list-make-tabulated-vector
+   entry-type
+   (lambda (param _)
+     (let ((val (guix-get-key-val entry param))
+           (fun (guix-get-key-val guix-list-column-value-methods
+                                  entry-type param)))
+       (if (and val fun)
+           (funcall fun val entry)
+         (guix-get-string val))))))
+
+(defun guix-list-get-one-line (str &optional _)
+  "Return one-line string from a multi-line STR."
+  (guix-get-one-line str))
+
+(defun guix-list-get-time (seconds &optional _)
+  "Return formatted time string from SECONDS."
+  (guix-get-time-string seconds))
+
+(defun guix-list-get-file-path (path &optional _)
+  "Return PATH button specification for `tabulated-list-entries'."
+  (list path
+        'face 'guix-list-file-path
+        'action (lambda (btn) (find-file (button-label btn)))
+        'follow-link t
+        'help-echo "Find file"))
+
+(defun guix-list-current-id ()
+  "Return ID of the current entry."
+  (or (tabulated-list-get-id)
+      (user-error "No entry here")))
+
+(defun guix-list-current-entry ()
+  "Return alist of the current entry info."
+  (guix-get-entry-by-id (guix-list-current-id) guix-entries))
+
+(defun guix-list-for-each-line (fun &rest args)
+  "Call FUN with ARGS for each entry line."
+  (or (derived-mode-p 'guix-list-mode)
+      (error "The current buffer is not in Guix List mode"))
+  (save-excursion
+    (goto-char (point-min))
+    (while (not (eobp))
+      (apply fun args)
+      (forward-line))))
+
+(defun guix-list-fold-lines (fun init)
+  "Fold over entry lines in the current list buffer.
+Call FUN with RESULT as argument for each line, using INIT as
+the initial value of RESULT.  Return the final result."
+  (let ((res init))
+    (guix-list-for-each-line
+     (lambda () (setq res (funcall fun res))))
+    res))
+
+
+;;; Marking and sorting
+
+(defvar-local guix-list-marked nil
+  "List of the marked entries.
+Each element of the list has a form:
+
+  (ID MARK-NAME . ARGS)
+
+ID is an entry ID.
+MARK-NAME is a symbol from `guix-list-mark-alist'.
+ARGS is a list of additional values.")
+
+(defvar guix-list-mark-alist
+  '((empty   . ?\s)
+    (general . ?*))
+  "Alist of available mark names and mark characters.")
+
+(defsubst guix-list-get-mark (name)
+  "Return mark character by its NAME."
+  (or (guix-get-key-val guix-list-mark-alist name)
+      (error "Mark '%S' not found" name)))
+
+(defsubst guix-list-get-mark-string (name)
+  "Return mark string by its NAME."
+  (string (guix-list-get-mark name)))
+
+(defun guix-list-current-mark ()
+  "Return mark character of the current line."
+  (char-after (line-beginning-position)))
+
+(defun guix-list-get-marked (&rest mark-names)
+  "Return list of specs of entries marked with any mark from MARK-NAMES.
+Entry specs are elements from `guix-list-marked' list.
+If MARK-NAMES are not specified, use all marks from
+`guix-list-mark-alist' except the `empty' one."
+  (or mark-names
+      (setq mark-names
+            (delq 'empty
+                  (mapcar #'car guix-list-mark-alist))))
+  (cl-remove-if-not (lambda (assoc)
+                      (memq (cadr assoc) mark-names))
+                    guix-list-marked))
+
+(defun guix-list-get-marked-args (mark-name)
+  "Return list of (ID . ARGS) elements from lines marked with MARK-NAME.
+See `guix-list-marked' for the meaning of ARGS."
+  (mapcar (lambda (spec)
+            (let ((id (car spec))
+                  (args (cddr spec)))
+              (cons id args)))
+          (guix-list-get-marked mark-name)))
+
+(defun guix-list-get-marked-id-list (&rest mark-names)
+  "Return list of IDs of entries marked with any mark from MARK-NAMES.
+See `guix-list-get-marked' for details."
+  (mapcar #'car (apply #'guix-list-get-marked mark-names)))
+
+(defun guix-list-mark (mark-name &optional advance &rest args)
+  "Put a mark on the current line.
+Also add the current entry to `guix-list-marked' using its ID and ARGS.
+MARK-NAME is a symbol from `guix-list-mark-alist'.
+If ADVANCE is non-nil, move forward by one line after marking.
+Interactively, put a general mark and move to the next line."
+  (interactive '(general t))
+  (let ((id (guix-list-current-id)))
+    (if (eq mark-name 'empty)
+        (setq guix-list-marked (assq-delete-all id guix-list-marked))
+      (let ((assoc (assq id guix-list-marked))
+            (val (cons mark-name args)))
+        (if assoc
+            (setcdr assoc val)
+          (push (cons id val) guix-list-marked)))))
+  (tabulated-list-put-tag (guix-list-get-mark-string mark-name)
+                          advance))
+
+(defun guix-list-mark-all (mark-name)
+  "Mark all lines with MARK-NAME mark.
+MARK-NAME is a symbol from `guix-list-mark-alist'.
+Interactively, put a general mark on all lines."
+  (interactive '(general))
+  (guix-list-for-each-line #'guix-list-mark mark-name))
+
+(defun guix-list-unmark ()
+  "Unmark the current line and move to the next line."
+  (interactive)
+  (guix-list-mark 'empty t))
+
+(defun guix-list-unmark-backward ()
+  "Move up one line and unmark it."
+  (interactive)
+  (forward-line -1)
+  (guix-list-mark 'empty))
+
+(defun guix-list-unmark-all ()
+  "Unmark all lines."
+  (interactive)
+  (guix-list-mark-all 'empty))
+
+(defun guix-list-restore-marks ()
+  "Put marks according to `guix-list-mark-alist'."
+  (guix-list-for-each-line
+   (lambda ()
+     (let ((mark-name (car (guix-get-key-val guix-list-marked
+                                             (guix-list-current-id)))))
+       (tabulated-list-put-tag
+        (guix-list-get-mark-string (or mark-name 'empty)))))))
+
+(defun guix-list-sort (&optional n)
+  "Sort guix list entries by the column at point.
+With a numeric prefix argument N, sort the Nth column.
+Same as `tabulated-list-sort', but also restore marks after sorting."
+  (interactive "P")
+  (tabulated-list-sort n)
+  (guix-list-restore-marks))
+
+
+(defvar guix-list-mode-map
+  (let ((map (make-sparse-keymap)))
+    (set-keymap-parent map tabulated-list-mode-map)
+    (define-key map (kbd "m")   'guix-list-mark)
+    (define-key map (kbd "*")   'guix-list-mark)
+    (define-key map (kbd "M")   'guix-list-mark-all)
+    (define-key map (kbd "u")   'guix-list-unmark)
+    (define-key map (kbd "U")   'guix-list-unmark-all)
+    (define-key map (kbd "DEL") 'guix-list-unmark-backward)
+    (define-key map [remap tabulated-list-sort] 'guix-list-sort)
+    map)
+  "Parent keymap for list buffers.")
+
+(define-derived-mode guix-list-mode tabulated-list-mode "Guix-List"
+  "Parent mode for displaying information in list buffers."
+  (setq tabulated-list-padding 2))
+
+(defmacro guix-list-define-entry-type (entry-type &rest args)
+  "Define common stuff for displaying ENTRY-TYPE entries in list buffers.
+
+Remaining argument (ARGS) should have a form [KEYWORD VALUE] ...  The
+following keywords are available:
+
+  - `:sort-key' - default sort key for the tabulated list buffer.
+
+  - `:invert-sort' - if non-nil, invert initial sort.
+
+  - `:marks' - default value for the defined
+    `guix-ENTRY-TYPE-mark-alist' variable.
+
+This macro defines the following functions:
+
+  - `guix-ENTRY-TYPE-describe' - display marked entries in info buffer.
+
+  - `guix-ENTRY-TYPE-mark-MARK-NAME' functions for each mark
+    specified in `:marks' argument."
+  (let* ((entry-type-str (symbol-name entry-type))
+         (entry-str      (concat entry-type-str " entries"))
+         (prefix         (concat "guix-" entry-type-str "-list"))
+         (mode-str       (concat prefix "-mode"))
+         (init-fun       (intern (concat prefix "-mode-initialize")))
+         (describe-fun   (intern (concat prefix "-describe")))
+         (marks-var      (intern (concat prefix "-mark-alist")))
+         (marks-val      nil)
+         (sort-key       nil)
+         (invert-sort    nil))
+
+    ;; Process the keyword args.
+    (while (keywordp (car args))
+      (pcase (pop args)
+        (`:sort-key    (setq sort-key (pop args)))
+        (`:invert-sort (setq invert-sort (pop args)))
+	(`:marks       (setq marks-val (pop args)))
+	(_ (pop args))))
+
+    `(progn
+       (defvar ,marks-var ',marks-val
+         ,(concat "Alist of additional marks for `" mode-str "'.\n"
+                  "Marks from this list are added to `guix-list-mark-alist'."))
+
+       ,@(mapcar (lambda (mark-spec)
+                   (let* ((mark-name (car mark-spec))
+                          (mark-name-str (symbol-name mark-name)))
+                     `(defun ,(intern (concat prefix "-mark-" mark-name-str "-simple")) ()
+                        ,(concat "Put '" mark-name-str "' mark and move to the next line.\n"
+                                 "Also add the current entry to `guix-list-marked'.")
+                        (interactive)
+                        (guix-list-mark ',mark-name t))))
+                 marks-val)
+
+       (defun ,describe-fun (&optional arg)
+         ,(concat "Describe " entry-str " marked with a general mark.\n"
+                  "If no entry is marked, describe the current " entry-type-str ".\n"
+                  "With prefix (if ARG is non-nil), describe the " entry-str "\n"
+                  "marked with any mark.")
+         (interactive "P")
+         (let* ((ids (or (apply #'guix-list-get-marked-id-list
+                                (unless arg '(general)))
+                         (list (guix-list-current-id))))
+                (count (length ids)))
+           (when (or (<= count guix-list-describe-warning-count)
+                     (y-or-n-p (format "Do you really want to describe %d entries? "
+                                       count)))
+             (,(intern (concat "guix-" entry-type-str "-info-get-show"))
+              'id ids))))
+
+       (defun ,init-fun ()
+         ,(concat "Initial settings for `" mode-str "'.")
+         ,(when sort-key
+            `(setq tabulated-list-sort-key
+                   (guix-list-get-sort-key
+                    ',entry-type ',sort-key ,invert-sort)))
+         (setq tabulated-list-format
+               (guix-list-get-list-format ',entry-type))
+         (setq-local guix-list-mark-alist
+                     (append guix-list-mark-alist ,marks-var))
+         (tabulated-list-init-header)))))
+
+(put 'guix-list-define-entry-type 'lisp-indent-function 'defun)
+
+
+;;; Displaying packages
+
+(guix-define-buffer-type list package)
+
+(guix-list-define-entry-type package
+  :sort-key name
+  :marks ((install . ?I)
+          (upgrade . ?U)
+          (delete  . ?D)))
+
+(defface guix-package-list-obsolete
+  '((t :inherit guix-package-info-obsolete))
+  "Face used if a package is obsolete."
+  :group 'guix-package-list)
+
+(defcustom guix-package-list-generation-marking-enabled nil
+  "If non-nil, allow putting marks in a list with 'generation packages'.
+
+By default this is disabled, because it may be confusing.  For
+example a package is installed in some generation, so a user can
+mark it for deletion in the list of packages from this
+generation, but the package may not be installed in the latest
+generation, so actually it cannot be deleted.
+
+If you managed to understand the explanation above or if you
+really know what you do or if you just don't care, you can set
+this variable to t.  It should not do much harm anyway (most
+likely)."
+  :type 'boolean
+  :group 'guix-package-list)
+
+(let ((map guix-package-list-mode-map))
+  (define-key map (kbd "RET") 'guix-package-list-describe)
+  (define-key map (kbd "x")   'guix-package-list-execute)
+  (define-key map (kbd "i")   'guix-package-list-mark-install)
+  (define-key map (kbd "^")   'guix-package-list-mark-upgrade)
+  (define-key map (kbd "d")   'guix-package-list-mark-delete))
+
+(defun guix-package-list-get-name (name entry)
+  "Return NAME of the package ENTRY.
+Colorize it with `guix-package-list-obsolete' if needed."
+  (guix-get-string name
+                   (when (guix-get-key-val entry 'obsolete)
+                     'guix-package-list-obsolete)))
+
+(defun guix-package-list-get-installed-outputs (installed &optional _)
+  "Return string with outputs from INSTALLED entries."
+  (guix-get-string
+   (mapcar (lambda (entry)
+             (guix-get-key-val entry 'output))
+           installed)))
+
+(defun guix-package-list-marking-check ()
+  "Signal an error if marking is disabled for the current buffer."
+  (when (and (not guix-package-list-generation-marking-enabled)
+             (derived-mode-p 'guix-package-list-mode)
+             (eq guix-search-type 'generation))
+    (error "Action marks are disabled for lists of 'generation packages'")))
+
+(defun guix-package-list-mark-install (&optional arg)
+  "Mark the current package for installation and move to the next line.
+With ARG, prompt for the outputs to install (several outputs may
+be separated with \",\")."
+  (interactive "P")
+  (guix-package-list-marking-check)
+  (let* ((entry (guix-list-current-entry))
+         (available (guix-get-key-val entry 'outputs))
+         (installed (guix-get-installed-outputs entry))
+         (to-install (if arg
+                         (guix-completing-read-multiple
+                          "Output(s) to install: " available nil t)
+                       '("out")))
+         (to-install (cl-set-difference to-install installed
+                                        :test #'string=)))
+    (if to-install
+        (apply #'guix-list-mark 'install t to-install)
+      (user-error "This package is already installed"))))
+
+(defun guix-package-list-mark-delete (&optional arg)
+  "Mark the current package for deletion and move to the next line.
+With ARG, prompt for the outputs to delete (several outputs may
+be separated with \",\")."
+  (interactive "P")
+  (guix-package-list-marking-check)
+  (let* ((entry (guix-list-current-entry))
+         (installed (guix-get-installed-outputs entry)))
+    (or installed
+        (user-error "This package is not installed"))
+    (let ((to-delete (when arg
+                       (guix-completing-read-multiple
+                        "Output(s) to delete: " installed nil t))))
+      (if to-delete
+          (apply #'guix-list-mark 'delete t to-delete)
+        (guix-package-list-mark-delete-simple)))))
+
+(defun guix-package-list-mark-upgrade ()
+  "Mark the current package for upgrading and move to the next line."
+  (interactive)
+  (guix-package-list-marking-check)
+  (let ((entry (guix-list-current-entry)))
+    (or (guix-get-installed-outputs entry)
+        (user-error "This package is not installed"))
+    (when (or (guix-get-key-val entry 'obsolete)
+              (y-or-n-p "This package is not obsolete.  Try to upgrade it anyway? "))
+      (guix-package-list-mark-upgrade-simple))))
+
+(defun guix-package-list-execute ()
+  "Perform actions on the marked packages."
+  (interactive)
+  (let ((actions (delq nil
+                       (mapcar #'guix-package-list-make-action
+                               '(install delete upgrade)))))
+    (if actions
+        (apply #'guix-process-package-actions actions)
+      (user-error "No operations specified"))))
+
+(defun guix-package-list-make-action (action-type)
+  "Return action specification for the packages marked with ACTION-TYPE.
+Return nil, if there are no packages marked with ACTION-TYPE.
+The specification is suitable for `guix-process-package-actions'."
+  (let ((specs (guix-list-get-marked-args action-type)))
+    (and specs (cons action-type specs))))
+
+
+;;; Displaying generations
+
+(guix-define-buffer-type list generation)
+
+(guix-list-define-entry-type generation
+  :sort-key number
+  :invert-sort t
+  :marks ((delete . ?D)))
+
+(let ((map guix-generation-list-mode-map))
+  (define-key map (kbd "RET") 'guix-generation-list-show-packages)
+  (define-key map (kbd "i")   'guix-generation-list-describe)
+  (define-key map (kbd "d")   'guix-generation-list-mark-delete-simple))
+
+(defun guix-generation-list-show-packages ()
+  "List installed packages for the generation at point."
+  (interactive)
+  (guix-package-list-get-show 'generation (guix-list-current-id)))
+
+(provide 'guix-list)
+
+;;; guix-list.el ends here

emacs/guix-main.scm

@@ -0,0 +1,603 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 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 License as published by
+;;; the Free Software Foundation; either version 3 of the License, 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 License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Information about packages and generations is passed to the elisp
+;; side in the form of alists of parameters (such as ‘name’ or
+;; ‘version’) and their values.  These alists are called "entries" in
+;; this code.  So to distinguish, just "package" in the name of a
+;; function means a guile object ("package" record) while
+;; "package entry" means alist of package parameters and values (see
+;; ‘package-param-alist’).
+;;
+;; "Entry" is probably not the best name for such alists, because there
+;; already exists "manifest-entry" which has nothing to do with the
+;; "entry" described above.  Do not be confused :)
+
+;; ‘get-entries’ function is the “entry point” for the elisp side to get
+;; information about packages and generations.
+
+;; Since name/version pair is not necessarily unique, we use
+;; `object-address' to identify a package (for ‘id’ parameter), if
+;; possible.  However for the obsolete packages (that can be found in
+;; installed manifest but not in a package directory), ‘id’ parameter is
+;; still "name-version" string.  So ‘id’ package parameter in the code
+;; below is either an object-address number or a full-name string.
+;;
+;; Important: as object addresses live only during guile session, elisp
+;; part should take care about updating information after "Guix REPL" is
+;; restarted (TODO!)
+;;
+;; ‘installed’ parameter of a package entry contains information about
+;; installed outputs.  It is a list of "installed entries" (see
+;; ‘package-installed-param-alist’).
+
+;; To speed-up the process of getting information, the following
+;; auxiliary variables are used:
+;;
+;; - `%packages' - VHash of "package address"/"package" pairs.
+;;
+;; - `%package-table' - Hash table of
+;;   "name+version key"/"list of packages" pairs.
+;;
+;; - `%current-manifest-entries-table' - Hash table of
+;;   "name+version key"/"list of manifest entries" pairs.  This variable
+;;   is set by `set-current-manifest-maybe!' when it is needed.
+
+;;; Code:
+
+(use-modules
+ (ice-9 vlist)
+ (ice-9 match)
+ (srfi srfi-1)
+ (srfi srfi-11)
+ (srfi srfi-19)
+ (srfi srfi-26)
+ (guix)
+ (guix packages)
+ (guix profiles)
+ (guix licenses)
+ (guix utils)
+ (guix ui)
+ (guix scripts package)
+ (gnu packages))
+
+(define-syntax-rule (first-or-false lst)
+  (and (not (null? lst))
+       (first lst)))
+
+(define full-name->name+version package-name->name+version)
+(define (name+version->full-name name version)
+  (string-append name "-" version))
+
+(define* (make-package-specification name #:optional version output)
+  (let ((full-name (if version
+                       (name+version->full-name name version)
+                       name)))
+    (if output
+        (string-append full-name ":" output)
+        full-name)))
+
+(define name+version->key cons)
+(define key->name+version car+cdr)
+
+(define %current-manifest #f)
+(define %current-manifest-entries-table #f)
+
+(define %packages
+  (fold-packages (lambda (pkg res)
+                   (vhash-consq (object-address pkg) pkg res))
+                 vlist-null))
+
+(define %package-table
+  (let ((table (make-hash-table (vlist-length %packages))))
+    (vlist-for-each
+     (lambda (elem)
+       (match elem
+         ((address . pkg)
+          (let* ((key (name+version->key (package-name pkg)
+                                         (package-version pkg)))
+                 (ref (hash-ref table key)))
+            (hash-set! table key
+                       (if ref (cons pkg ref) (list pkg)))))))
+     %packages)
+    table))
+
+;; FIXME get rid of this function!
+(define (set-current-manifest-maybe! profile)
+  (define (manifest-entries->hash-table entries)
+    (let ((entries-table (make-hash-table (length entries))))
+      (for-each (lambda (entry)
+                  (let* ((key (name+version->key
+                               (manifest-entry-name entry)
+                               (manifest-entry-version entry)))
+                         (ref (hash-ref entries-table key)))
+                    (hash-set! entries-table key
+                               (if ref (cons entry ref) (list entry)))))
+                entries)
+      entries-table))
+
+  (when profile
+    (let ((manifest (profile-manifest profile)))
+      (unless (and (manifest? %current-manifest)
+                   (equal? manifest %current-manifest))
+        (set! %current-manifest manifest)
+        (set! %current-manifest-entries-table
+              (manifest-entries->hash-table
+               (manifest-entries manifest)))))))
+
+(define (manifest-entries-by-name+version name version)
+  (or (hash-ref %current-manifest-entries-table
+                (name+version->key name version))
+      '()))
+
+(define (packages-by-name+version name version)
+  (or (hash-ref %package-table
+                (name+version->key name version))
+      '()))
+
+(define (packages-by-full-name full-name)
+  (call-with-values
+      (lambda () (full-name->name+version full-name))
+    packages-by-name+version))
+
+(define (package-by-address address)
+  (and=> (vhash-assq address %packages)
+         cdr))
+
+(define (packages-by-id id)
+  (if (integer? id)
+      (let ((pkg (package-by-address id)))
+        (if pkg (list pkg) '()))
+      (packages-by-full-name id)))
+
+(define (package-by-id id)
+  (first-or-false (packages-by-id id)))
+
+(define (newest-package-by-id id)
+  (and=> (id->name+version id)
+         (lambda (name)
+           (first-or-false (find-best-packages-by-name name #f)))))
+
+(define (id->name+version id)
+  (if (integer? id)
+      (and=> (package-by-address id)
+             (lambda (pkg)
+               (values (package-name pkg)
+                       (package-version pkg))))
+      (full-name->name+version id)))
+
+(define (fold-manifest-entries proc init)
+  "Fold over `%current-manifest-entries-table'.
+Call (PROC NAME VERSION ENTRIES RESULT) for each element of the hash
+table, using INIT as the initial value of RESULT."
+  (hash-fold (lambda (key entries res)
+               (let-values (((name version) (key->name+version key)))
+                 (proc name version entries res)))
+             init
+             %current-manifest-entries-table))
+
+(define (fold-object proc init obj)
+  (fold proc init
+        (if (list? obj) obj (list obj))))
+
+(define* (object-transformer param-alist #:optional (params '()))
+  "Return function for transforming an object into alist of parameters/values.
+
+PARAM-ALIST is alist of available object parameters (symbols) and functions
+returning values of these parameters.  Each function is called with object as
+a single argument.
+
+PARAMS is list of parameters from PARAM-ALIST that should be returned by a
+resulting function.  If PARAMS is not specified or is an empty list, use all
+available parameters.
+
+Example:
+
+  (let ((alist `((plus1 . ,1+) (minus1 . ,1-) (mul2 . ,(cut * 2 <>))))
+        (number->alist (object-transformer alist '(plus1 mul2))))
+    (number->alist 8))
+  =>
+  ((plus1 . 9) (mul2 . 16))
+"
+  (let ((alist (let ((use-all-params (null? params)))
+                 (filter-map (match-lambda
+                              ((param . fun)
+                               (and (or use-all-params
+                                        (memq param params))
+                                    (cons param fun)))
+                              (_ #f))
+                             param-alist))))
+    (lambda (object)
+      (map (match-lambda
+            ((param . fun)
+             (cons param (fun object))))
+           alist))))
+
+(define package-installed-param-alist
+  (list
+   (cons 'output       manifest-entry-output)
+   (cons 'path         manifest-entry-item)
+   (cons 'dependencies manifest-entry-dependencies)))
+
+(define manifest-entry->installed-entry
+  (object-transformer package-installed-param-alist))
+
+(define (manifest-entries->installed-entries entries)
+  (map manifest-entry->installed-entry entries))
+
+(define (installed-entries-by-name+version name version)
+  (manifest-entries->installed-entries
+   (manifest-entries-by-name+version name version)))
+
+(define (installed-entries-by-package package)
+  (installed-entries-by-name+version (package-name package)
+                                     (package-version package)))
+
+(define (package-inputs-names inputs)
+  "Return list of full names of the packages from package INPUTS."
+  (filter-map (match-lambda
+               ((_ (? package? package))
+                (package-full-name package))
+               (_ #f))
+              inputs))
+
+(define (package-license-names package)
+  "Return list of license names of the PACKAGE."
+  (fold-object (lambda (license res)
+                 (if (license? license)
+                     (cons (license-name license) res)
+                     res))
+               '()
+               (package-license package)))
+
+(define (package-unique? package)
+  "Return #t if PACKAGE is a single package with such name/version."
+  (null? (cdr (packages-by-name+version (package-name package)
+                                        (package-version package)))))
+
+(define package-param-alist
+  (list
+   (cons 'id                object-address)
+   (cons 'name              package-name)
+   (cons 'version           package-version)
+   (cons 'license           package-license-names)
+   (cons 'synopsis          package-synopsis)
+   (cons 'description       package-description)
+   (cons 'home-url          package-home-page)
+   (cons 'outputs           package-outputs)
+   (cons 'non-unique        (negate package-unique?))
+   (cons 'inputs            (lambda (pkg) (package-inputs-names
+                                      (package-inputs pkg))))
+   (cons 'native-inputs     (lambda (pkg) (package-inputs-names
+                                      (package-native-inputs pkg))))
+   (cons 'propagated-inputs (lambda (pkg) (package-inputs-names
+                                      (package-propagated-inputs pkg))))
+   (cons 'location          (lambda (pkg) (location->string
+                                      (package-location pkg))))
+   (cons 'installed         installed-entries-by-package)))
+
+(define (package-param package param)
+  "Return the value of a PACKAGE PARAM."
+  (define (accessor param)
+    (and=> (assq param package-param-alist)
+           cdr))
+  (and=> (accessor param)
+         (cut <> package)))
+
+(define (matching-package-entries ->entry predicate)
+  "Return list of package entries for the matching packages.
+PREDICATE is called on each package."
+  (fold-packages (lambda (pkg res)
+                   (if (predicate pkg)
+                       (cons (->entry pkg) res)
+                       res))
+                 '()))
+
+(define (make-obsolete-package-entry name version entries)
+  "Return package entry for an obsolete package with NAME and VERSION.
+ENTRIES is a list of manifest entries used to get installed info."
+  `((id        . ,(name+version->full-name name version))
+    (name      . ,name)
+    (version   . ,version)
+    (outputs   . ,(map manifest-entry-output entries))
+    (obsolete  . #t)
+    (installed . ,(manifest-entries->installed-entries entries))))
+
+(define (package-entries-by-name+version ->entry name version)
+  "Return list of package entries for packages with NAME and VERSION."
+  (let ((packages (packages-by-name+version name version)))
+    (if (null? packages)
+        (let ((entries (manifest-entries-by-name+version name version)))
+          (if (null? entries)
+              '()
+              (list (make-obsolete-package-entry name version entries))))
+        (map ->entry packages))))
+
+(define (package-entries-by-spec profile ->entry spec)
+  "Return list of package entries for packages with name specification SPEC."
+  (set-current-manifest-maybe! profile)
+  (let-values (((name version)
+                (full-name->name+version spec)))
+    (if version
+        (package-entries-by-name+version ->entry name version)
+        (matching-package-entries
+         ->entry
+         (lambda (pkg) (string=? name (package-name pkg)))))))
+
+(define (package-entries-by-regexp profile ->entry regexp match-params)
+  "Return list of package entries for packages matching REGEXP string.
+MATCH-PARAMS is a list of parameters that REGEXP can match."
+  (define (package-match? package regexp)
+    (any (lambda (param)
+           (let ((val (package-param package param)))
+             (and (string? val) (regexp-exec regexp val))))
+         match-params))
+
+  (set-current-manifest-maybe! profile)
+  (let ((re (make-regexp regexp regexp/icase)))
+    (matching-package-entries ->entry (cut package-match? <> re))))
+
+(define (package-entries-by-ids profile ->entry ids)
+  "Return list of package entries for packages matching KEYS.
+IDS may be an object-address, a full-name or a list of such elements."
+  (set-current-manifest-maybe! profile)
+  (fold-object
+   (lambda (id res)
+     (if (integer? id)
+         (let ((pkg (package-by-address id)))
+           (if pkg
+               (cons (->entry pkg) res)
+               res))
+         (let ((entries (package-entries-by-spec #f ->entry id)))
+           (if (null? entries)
+               res
+               (append res entries)))))
+   '()
+   ids))
+
+(define (newest-available-package-entries profile ->entry)
+  "Return list of package entries for the newest available packages."
+  (set-current-manifest-maybe! profile)
+  (vhash-fold (lambda (name elem res)
+                (match elem
+                  ((version newest pkgs ...)
+                   (cons (->entry newest) res))))
+              '()
+              (find-newest-available-packages)))
+
+(define (all-available-package-entries profile ->entry)
+  "Return list of package entries for all available packages."
+  (set-current-manifest-maybe! profile)
+  (matching-package-entries ->entry (const #t)))
+
+(define (manifest-package-entries ->entry)
+  "Return list of package entries for the current manifest."
+  (fold-manifest-entries
+   (lambda (name version entries res)
+     ;; We don't care about duplicates for the list of
+     ;; installed packages, so just take any package (car)
+     ;; matching name+version
+     (cons (car (package-entries-by-name+version ->entry name version))
+           res))
+   '()))
+
+(define (installed-package-entries profile ->entry)
+  "Return list of package entries for all installed packages."
+  (set-current-manifest-maybe! profile)
+  (manifest-package-entries ->entry))
+
+(define (generation-package-entries profile ->entry generation)
+  "Return list of package entries for packages from GENERATION."
+  (set-current-manifest-maybe!
+   (generation-file-name profile generation))
+  (manifest-package-entries ->entry))
+
+(define (obsolete-package-entries profile _)
+  "Return list of package entries for obsolete packages."
+  (set-current-manifest-maybe! profile)
+  (fold-manifest-entries
+   (lambda (name version entries res)
+     (let ((packages (packages-by-name+version name version)))
+       (if (null? packages)
+           (cons (make-obsolete-package-entry name version entries) res)
+           res)))
+   '()))
+
+
+;;; Generation entries
+
+(define (profile-generations profile)
+  "Return list of generations for PROFILE."
+  (let ((generations (generation-numbers profile)))
+    (if (equal? generations '(0))
+        '()
+        generations)))
+
+(define (generation-param-alist profile)
+  "Return alist of generation parameters and functions for PROFILE."
+  (list
+   (cons 'id          identity)
+   (cons 'number      identity)
+   (cons 'prev-number (cut previous-generation-number profile <>))
+   (cons 'path        (cut generation-file-name profile <>))
+   (cons 'time        (lambda (gen)
+                        (time-second (generation-time profile gen))))))
+
+(define (matching-generation-entries profile ->entry predicate)
+  "Return list of generation entries for the matching generations.
+PREDICATE is called on each generation."
+  (filter-map (lambda (gen)
+                (and (predicate gen) (->entry gen)))
+              (profile-generations profile)))
+
+(define (last-generation-entries profile ->entry number)
+  "Return list of last NUMBER generation entries.
+If NUMBER is 0 or less, return all generation entries."
+  (let ((generations (profile-generations profile))
+        (number (if (<= number 0) +inf.0 number)))
+    (map ->entry
+         (if (> (length generations) number)
+             (list-head  (reverse generations) number)
+             generations))))
+
+(define (all-generation-entries profile ->entry)
+  "Return list of all generation entries."
+  (last-generation-entries profile ->entry +inf.0))
+
+(define (generation-entries-by-ids profile ->entry ids)
+  "Return list of generation entries for generations matching IDS.
+IDS is a list of generation numbers."
+  (matching-generation-entries profile ->entry (cut memq <> ids)))
+
+
+;;; Getting package/generation entries
+
+(define %package-entries-functions
+  (alist->vhash
+   `((id               . ,package-entries-by-ids)
+     (name             . ,package-entries-by-spec)
+     (regexp           . ,package-entries-by-regexp)
+     (all-available    . ,all-available-package-entries)
+     (newest-available . ,newest-available-package-entries)
+     (installed        . ,installed-package-entries)
+     (obsolete         . ,obsolete-package-entries)
+     (generation       . ,generation-package-entries))
+   hashq))
+
+(define %generation-entries-functions
+  (alist->vhash
+   `((id   . ,generation-entries-by-ids)
+     (last . ,last-generation-entries)
+     (all  . ,all-generation-entries))
+   hashq))
+
+(define (get-entries profile params entry-type search-type search-vals)
+  "Return list of entries.
+ENTRY-TYPE and SEARCH-TYPE define a search function that should be
+applied to PARAMS and VALS."
+  (let-values (((vhash ->entry)
+                (case entry-type
+                  ((package)
+                   (values %package-entries-functions
+                           (object-transformer
+                            package-param-alist params)))
+                  ((generation)
+                   (values %generation-entries-functions
+                           (object-transformer
+                            (generation-param-alist profile) params)))
+                  (else (format (current-error-port)
+                                "Wrong entry type '~a'" entry-type)))))
+    (match (vhash-assq search-type vhash)
+      ((key . fun)
+       (apply fun profile ->entry search-vals))
+      (_ '()))))
+
+
+;;; Actions
+
+(define* (package->manifest-entry* package #:optional output)
+  (and package
+       (begin
+         (check-package-freshness package)
+         (package->manifest-entry package output))))
+
+(define* (make-install-manifest-entries id #:optional output)
+  (package->manifest-entry* (package-by-id id) output))
+
+(define* (make-upgrade-manifest-entries id #:optional output)
+  (package->manifest-entry* (newest-package-by-id id) output))
+
+(define* (make-manifest-pattern id #:optional output)
+  "Make manifest pattern from a package ID and OUTPUT."
+  (let-values (((name version)
+                (id->name+version id)))
+    (and name version
+         (manifest-pattern
+          (name name)
+          (version version)
+          (output output)))))
+
+(define (convert-action-pattern pattern proc)
+  "Convert action PATTERN into a list of objects returned by PROC.
+PROC is called: (PROC ID) or (PROC ID OUTPUT)."
+  (match pattern
+    ((id . outputs)
+     (if (null? outputs)
+         (let ((obj (proc id)))
+           (if obj (list obj) '()))
+         (filter-map (cut proc id <>)
+                     outputs)))
+    (_ '())))
+
+(define (convert-action-patterns patterns proc)
+  (append-map (cut convert-action-pattern <> proc)
+              patterns))
+
+(define* (process-package-actions
+          profile #:key (install '()) (upgrade '()) (remove '())
+          (use-substitutes? #t) dry-run?)
+  "Perform package actions.
+
+INSTALL, UPGRADE, REMOVE are lists of 'package action patterns'.
+Each pattern should have the following form:
+
+  (ID . OUTPUTS)
+
+ID is an object address or a full-name of a package.
+OUTPUTS is a list of package outputs (may be an empty list)."
+  (format #t "The process begins ...~%")
+  (let* ((install (append
+                   (convert-action-patterns
+                    install make-install-manifest-entries)
+                   (convert-action-patterns
+                    upgrade make-upgrade-manifest-entries)))
+         (remove (convert-action-patterns remove make-manifest-pattern))
+         (transaction (manifest-transaction (install install)
+                                            (remove remove)))
+         (manifest (profile-manifest profile))
+         (new-manifest (manifest-perform-transaction
+                        manifest transaction)))
+    (unless (and (null? install) (null? remove))
+      (let* ((store (open-connection))
+             (derivation (run-with-store
+                          store (profile-derivation new-manifest)))
+             (derivations (list derivation))
+             (new-profile (derivation->output-path derivation)))
+        (set-build-options store
+                           #:use-substitutes? use-substitutes?)
+        (manifest-show-transaction store manifest transaction
+                                   #:dry-run? dry-run?)
+        (show-what-to-build store derivations
+                            #:use-substitutes? use-substitutes?
+                            #:dry-run? dry-run?)
+        (unless dry-run?
+          (let ((name (generation-file-name
+                       profile
+                       (+ 1 (generation-number profile)))))
+            (and (build-derivations store derivations)
+                 (let* ((entries (manifest-entries new-manifest))
+                        (count   (length entries)))
+                   (switch-symlinks name new-profile)
+                   (switch-symlinks profile name)
+                   (format #t (N_ "~a package in profile~%"
+                                  "~a packages in profile~%"
+                                  count)
+                           count)))))))))
+

emacs/guix-utils.el

@@ -0,0 +1,160 @@
+;;; guix-utils.el --- General utility functions
+
+;; Copyright © 2014 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides auxiliary general functions for guix.el package.
+
+;;; Code:
+
+;; (require 'cl-lib)
+
+(defvar guix-true-string "Yes")
+(defvar guix-false-string "–")
+(defvar guix-list-separator ", ")
+
+(defvar guix-time-format "%F %T"
+  "String used to format time values.
+For possible formats, see `format-time-string'.")
+
+(defun guix-get-string (val &optional face)
+  "Convert VAL into a string and return it.
+
+VAL can be an expression of any type.
+If VAL is t/nil, it is replaced with
+`guix-true-string'/`guix-false-string'.
+If VAL is list, its elements are concatenated using
+`guix-list-separator'.
+
+If FACE is non-nil, propertize returned string with this FACE."
+  (let ((str (cond
+              ((stringp val) val)
+              ((null val) guix-false-string)
+              ((eq t val) guix-true-string)
+              ((numberp val) (number-to-string val))
+              ((listp val) (mapconcat #'guix-get-string
+                                      val guix-list-separator))
+              (t (prin1-to-string val)))))
+    (if (and val face)
+        (propertize str 'face face)
+      str)))
+
+(defun guix-get-time-string (seconds)
+  "Return formatted time string from SECONDS.
+Use `guix-time-format'."
+  (format-time-string guix-time-format (seconds-to-time seconds)))
+
+(defun guix-get-one-line (str)
+  "Return one-line string from a multi-line STR."
+  (replace-regexp-in-string "\n" " " str))
+
+(defun guix-format-insert (val &optional face format)
+  "Convert VAL into a string and insert it at point.
+If FACE is non-nil, propertize VAL with FACE.
+If FORMAT is non-nil, format VAL with FORMAT."
+  (let ((str (guix-get-string val face)))
+    (insert (if format
+                (format format str)
+              str))))
+
+(defun guix-mapinsert (function sequence separator)
+  "Like `mapconcat' but for inserting text.
+Apply FUNCTION to each element of SEQUENCE, and insert SEPARATOR
+at point between each FUNCTION call."
+  (when sequence
+    (funcall function (car sequence))
+    (mapc (lambda (obj)
+            (insert separator)
+            (funcall function obj))
+          (cdr sequence))))
+
+(defun guix-insert-button (label face action &optional message
+                                 &rest properties)
+  "Make button with LABEL and insert it at point.
+Propertize button with FACE.
+ACTION is a function called when the button is pressed.  It
+should accept button as the argument.
+MESSAGE is a button message.
+See `insert-text-button' for the meaning of PROPERTIES."
+  (if (null label)
+      (guix-format-insert nil)
+    (apply #'insert-text-button
+           label
+           'face face
+           'action action
+           'follow-link t
+           'help-echo message
+           properties)))
+
+(defun guix-split-insert (val &optional face col separator)
+  "Convert VAL into a string, split it and insert at point.
+
+If FACE is non-nil, propertize returned string with this FACE.
+
+If COL is non-nil and result string is a one-line string longer
+than COL, split it into several short lines.
+
+Separate inserted lines with SEPARATOR."
+  (if (null val)
+      (guix-format-insert nil)
+    (let ((strings (guix-split-string (guix-get-string val) col)))
+      (guix-mapinsert (lambda (str) (guix-format-insert str face))
+                      strings
+                      (or separator "")))))
+
+(defun guix-split-string (str &optional col)
+  "Split string STR by lines and return list of result strings.
+If COL is non-nil and STR is a one-line string longer than COL,
+split it into several short lines."
+  (let ((strings (split-string str "\n *")))
+    (if (and col
+             (null (cdr strings))       ; if not multi-line
+             (> (length str) col))
+        (split-string (guix-get-filled-string str col) "\n")
+      strings)))
+
+(defun guix-get-filled-string (str col)
+  "Return string by filling STR to column COL."
+  (with-temp-buffer
+    (insert str)
+    (let ((fill-column col))
+      (fill-region (point-min) (point-max)))
+    (buffer-string)))
+
+(defun guix-completing-read-multiple (prompt table &optional predicate
+                                      require-match initial-input
+                                      hist def inherit-input-method)
+  "Same as `completing-read-multiple' but remove duplicates in result."
+  (cl-remove-duplicates
+   (completing-read-multiple prompt table predicate
+                             require-match initial-input
+                             hist def inherit-input-method)
+   :test #'string=))
+
+(defun guix-get-key-val (alist &rest keys)
+  "Return value from ALIST by KEYS.
+ALIST is alist of alists of alists ... which can be consecutively
+accessed with KEYS."
+  (let ((val alist))
+    (dolist (key keys val)
+      (setq val (cdr (assq key val))))))
+
+(provide 'guix-utils)
+
+;;; guix-utils.el ends here

emacs/guix.el

@@ -0,0 +1,141 @@
+;;; guix.el --- Interface for GNU Guix package manager
+
+;; Copyright © 2014 Alex Kost <alezost@gmail.com>
+
+;; Package-Requires: ((geiser "0.3"))
+;; Keywords: tools
+
+;; 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 License as published by
+;; the Free Software Foundation, either version 3 of the License, 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 License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This package provides an interface for searching, listing and getting
+;; information about Guix packages and generations; and for
+;; installing/upgrading/removing packages.
+
+;;; Code:
+
+(require 'guix-list)
+(require 'guix-info)
+
+(defgroup guix nil
+  "Interface for Guix package manager."
+  :prefix "guix-"
+  :group 'external)
+
+(defcustom guix-list-single-package nil
+  "If non-nil, list a package even if it is the only matching result.
+If nil, show a single package in the info buffer."
+  :type 'boolean
+  :group 'guix)
+
+(defcustom guix-show-generations-function 'guix-generation-list-get-show
+  "Default function used to display generations."
+  :type '(choice (function-item guix-generation-list-get-show)
+                 (function-item guix-generation-info-get-show))
+  :group 'guix)
+
+(defvar guix-search-params '(name synopsis description)
+  "Default list of package parameters for searching by regexp.")
+
+(defvar guix-search-history nil
+  "A history of minibuffer prompts.")
+
+(defun guix-get-show-packages (search-type &rest search-vals)
+  "Search for packages and show results.
+
+See `guix-get-entries' for the meaning of SEARCH-TYPE and
+SEARCH-VALS.
+
+Results are displayed in the list buffer, unless a single package
+is found and `guix-list-single-package' is nil."
+  (let* ((list-params (guix-package-list-get-params-for-receiving))
+         (packages (guix-get-entries 'package search-type
+                                     search-vals list-params)))
+    (if (or guix-list-single-package
+            (cdr packages))
+        (guix-package-list-set packages search-type search-vals)
+      (let ((info-params (guix-package-info-get-params-for-receiving)))
+        (unless (equal list-params info-params)
+          ;; If we don't have required info, we should receive it again
+          (setq packages (guix-get-entries 'package search-type
+                                           search-vals info-params))))
+      (guix-package-info-set packages search-type search-vals))))
+
+(defun guix-get-show-generations (search-type &rest search-vals)
+  "Search for generations and show results."
+  (apply guix-show-generations-function search-type search-vals))
+
+;;;###autoload
+(defun guix-search-by-name (name)
+  "Search for Guix packages by NAME.
+NAME is a string with name specification.  It may optionally contain
+a version number.  Examples: \"guile\", \"guile-2.0.11\"."
+  (interactive
+   (list (read-string "Package name: " nil 'guix-search-history)))
+  (guix-get-show-packages 'name name))
+
+;;;###autoload
+(defun guix-search-by-regexp (regexp &rest params)
+  "Search for Guix packages by REGEXP.
+PARAMS are package parameters that should be searched.
+If PARAMS are not specified, use `guix-search-params'."
+  (interactive
+   (list (read-string "Regexp: " nil 'guix-search-history)))
+  (or params (setq params guix-search-params))
+  (guix-get-show-packages 'regexp regexp params))
+
+;;;###autoload
+(defun guix-installed-packages ()
+  "Display information about installed Guix packages."
+  (interactive)
+  (guix-get-show-packages 'installed))
+
+;;;###autoload
+(defun guix-obsolete-packages ()
+  "Display information about obsolete Guix packages."
+  (interactive)
+  (guix-get-show-packages 'obsolete))
+
+;;;###autoload
+(defun guix-all-available-packages ()
+  "Display information about all available Guix packages."
+  (interactive)
+  (guix-get-show-packages 'all-available))
+
+;;;###autoload
+(defun guix-newest-available-packages ()
+  "Display information about the newest available Guix packages."
+  (interactive)
+  (guix-get-show-packages 'newest-available))
+
+;;;###autoload
+(defun guix-generations (&optional number)
+  "Display information about last NUMBER generations.
+If NUMBER is nil, display all generations.
+
+Generations can be displayed in a list or info buffers depending
+on `guix-show-generations-function'.
+
+Interactively, NUMBER is defined by a numeric prefix."
+  (interactive "P")
+  (if (numberp number)
+      (guix-get-show-generations 'last number)
+    (guix-get-show-generations 'all)))
+
+(provide 'guix)
+
+;;; guix.el ends here