* emacs/guix-main.scm (register-package, packages-from-file): New procedures.
(%patterns-makers): Add 'from-file' search type.
* emacs/guix-messages.el (guix-messages): Add messages for it.
* emacs/guix-ui-package.el (guix-package-from-file): New command.
(guix-package-info-insert-location): Adjust for 'from-file' type.
* doc/emacs.texi (Emacs Commands): Document it.

* emacs/guix-license.el (guix-license-file): New procedure.
(guix-find-license-definition): New command.
* doc/emacs.texi (Emacs Licenses): Document it.

* emacs/guix-main.scm (%package-location-param-alist): New variable.
(package-location->sexp, package-location-entries): New procedures.
* emacs/guix-ui-location.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Package Locations): Document 'guix-locations'.
* NEWS: Mention it.

* doc/emacs.texi (Emacs Commands): Move description of 'guix-edit'
command to...
(Emacs Package Locations): ... here.  Document 'guix-find-location'.
New node.
* doc/guix.texi (Top): Add it.

* emacs/guix-main.scm (packages-by-location-file, package-location-files):
New procedures.
(%patterns-makers): Add 'location' search type.
* emacs/guix-messages.el (guix-message-packages-by-location): New procedure.
(guix-messages): Use it.
* emacs/guix-read.el (guix-package-locations)
(guix-read-package-location): New procedures.
* emacs/guix-ui-package.el (guix-packages-by-location): New command.
* doc/emacs.texi (Emacs Commands): Document it.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

* doc/emacs.texi (Emacs Initial Setup): Mention that "guix package -i
guix" is an easy way.  Warn that "make install" may lead to an outdated
code.

'guix-init' served 2 purposes:

- to autoload guix commands (by requiring 'guix-autoloads');
- and to autoload Emacs packages installed with Guix (by requiring
  'guix-emacs').

The second purpose is not actual anymore, as Emacs package handles this
task now, so there is no need in 'guix-init' anymore.

* emacs/guix-init.el: Do not require 'guix-emacs'.  Add a deprecation
  message.
* doc/emacs.texi (Emacs Initial Setup): Recommend to use
  'guix-autoloads' instead of 'guix-init'.

* emacs/guix-ui-package.el (guix-installed-user-packages)
(guix-installed-system-packages): New commands.
* doc/emacs.texi (Emacs Commands): Document them.

* emacs/guix-base.el (guix-read-directory): New procedure.
(guix-find-location, guix-edit): Add optional 'directory' argument.
* emacs/guix-ui-package.el (guix-package-list-edit)
(guix-output-list-edit): Likewise.
* doc/emacs.texi (Emacs Commands): Mention "C-u".

* doc/emacs.texi (Emacs Commands): Document "M-x guix-edit".
* doc/guix.texi (Invoking guix edit): Mention it.

* emacs/guix-emacs.el: (guix-emacs-directories): New procedure.
(guix-emacs-find-autoloads-in-directory): Rename to...
(guix-emacs-find-autoloads): ... this.
(guix-emacs-load-autoloads): Remove.  Replace with...
(guix-emacs-autoload-packages): ... this.  New procedure.  At first,
find a list of directories with Emacs packages, then add them to
'load-path' and finally, load autoloads.
* doc/emacs.texi (Emacs Initial Setup): Adjust accordingly.

* doc/images/dmd-graph.dot: Rename to...
* doc/images/shepherd-graph.dot: ... this.
* doc.am (DOT_FILES): Adjust accordingly.
* guix/scripts/system.scm (dmd-service-node-label)
  (dmd-service-node-type, export-dmd-graph): Rename to...
  (shepherd-service-node-label, shepherd-service-node-type)
  (export-shepherd-graph): ... this.
  (show-help, process-action, process-command): Rename 'dmd-graph' to
  'shepherd-graph'.
* emacs/guix-command.el (guix-command-additional-execute-arguments)
  (guix-command-special-executors): Likewise.
* doc/guix.texi: Likewise.
* doc/emacs.texi (Emacs Popup Interface): Likewise.

* emacs/guix-main.scm (%license-param-alist): New variable.
  (license->sexp, find-licenses, license-entries): New procedures.
* emacs/guix-license.el (guix-license-get-entries)
  (guix-license-get-display, guix-license-insert-packages-button)
  (guix-license-insert-comment, guix-license-list-describe)
  (guix-license-list-show-packages): New procedures.
  (guix-licenses): New command.
* doc/emacs.texi (Emacs Licenses): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Add it.
* NEWS: Mention new interface.

* emacs/guix-main.scm (packages-by-license): New procedure.
(%patterns-makers): Add 'license' search type.
* emacs/guix-messages.el (guix-message-packages-by-license): New procedure.
(guix-messages): Use it.
* emacs/guix-ui-package.el (guix-packages-by-license): New command.
* doc/emacs.texi (Emacs Commands): Document it.

* emacs/guix-ui-package.el (guix-package-license): New button type.
  (guix-package-info-format, guix-output-info-format): Use it.
* doc/emacs.texi (Emacs Info buffer): Mention it.

* emacs/guix-ui-package.el (guix-search-by-name): New command.
* doc/emacs.texi (Emacs Commands): Document it.

* emacs/guix-ui-package.el (guix-search-by-name): Rename to...
  (guix-packages-by-name): ... this.  Complete package name.
* doc/emacs.texi (Emacs Commands): Likewise.

* emacs/guix-main.scm (system-generation-boot-parameters)
(system-generation-param-alist, system-generation-sexps): New procedures.
(entries): Add 'system-generation' entry type.
* emacs/guix-messages.el (guix-result-message): Use the same messages
  for 'generation' and 'system-generation' entry types.
* emacs/guix-ui-system-generation.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Commands): Document new commands.
* NEWS: Mention new interface.

* emacs/guix-ui-package.el (guix-package-list-latest-builds): New
  procedure.
  (guix-package-list-mode-map): Bind "B" key to it.
  (guix-output-list-mode-map): Likewise.
* doc/emacs.texi (Emacs List buffer): Document it.

* emacs/guix-utils.el (guix-hexify, guix-number->bool): New procedures.
  (guix-while-null): New macro.
* emacs/guix-hydra.el: New file.
* emacs/guix-hydra-build.el: New file.
* emacs/guix-hydra-jobset.el: New file.
* emacs.am (ELFILES): Add them.
* doc/emacs.texi (Emacs Hydra): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Add it.
  (Substitutes): Mention Emacs interface.

Move the code for packages/generations interface from "guix-info.el",
"guix-list.el", "guix-base.el" and "guix.el" to "guix-ui-package.el" and
"guix-ui-generation.el".

* emacs/guix-base.el (guix-package-entry->name-specification)
  (guix-package-entries->name-specifications)
  (guix-package-id-and-output-by-output-id)
  (guix-package-installed-outputs, guix-process-package-actions)
  (guix-package-list-type, guix-package-info-type)
  (guix-continue-package-operation-p, guix-get-package-strings)
  (guix-insert-package-strings): Move to "guix-ui-package.el".
  (guix-generation-packages-buffer-name-function, guix-output-name-width)
  (guix-generation-packages-update-buffer, guix-generation-packages)
  (guix-generation-packages-buffer-name-default)
  (guix-generation-packages-buffer-name-long)
  (guix-generation-packages-buffer-name, guix-generation-packages-buffer)
  (guix-generation-insert-packages, guix-generation-insert-package)
  (guix-profile-generation-manifest-file, guix-delete-generations)
  (guix-profile-generation-packages-buffer, guix-switch-to-generation):
  Move to "guix-ui-generation.el".
* emacs/guix-info.el (guix-package-location, guix-package-name)
  (guix-package-source, guix-package-info-source)
  (guix-package-info-heading, guix-package-info-license)
  (guix-package-info-name, guix-package-info-name-button)
  (guix-package-info-version, guix-package-info-location)
  (guix-package-info-synopsis, guix-package-info-description)
  (guix-package-info-obsolete, guix-package-info-installed-outputs)
  (guix-package-info-uninstalled-outputs)
  (guix-package-info-insert-heading)
  (guix-package-info-define-insert-inputs)
  (guix-package-info-obsolete-string)
  (guix-package-info-insert-obsolete-text)
  (guix-package-info-insert-non-unique-text)
  (guix-package-info-insert-outputs, guix-package-info-insert-output)
  (guix-package-info-insert-action-button)
  (guix-package-info-auto-find-source)
  (guix-package-info-auto-download-source)
  (guix-package-info-download-buffer, guix-package-info-show-source)
  (guix-package-info-download-source, guix-package-info-insert-source)
  (guix-package-info-redisplay-after-download)
  (guix-output-info-insert-version, guix-output-info-insert-output):
  Move to "guix-ui-package.el".
  (guix-generation-info-number, guix-generation-info-current)
  (guix-generation-not-current, guix-generation-info-insert-number)
  (guix-generation-info-insert-current): Move to "guix-ui-generation.el".
* emacs/guix-list.el (guix-package-list-generation-marking-enabled)
  (guix-package-list-installed, guix-package-list-obsolete)
  (guix-package-list-get-name, guix-package-list-get-installed-outputs)
  (guix-package-list-marking-check, guix-package-list-mark-outputs)
  (guix-package-list-mark-install, guix-package-list-mark-delete)
  (guix-package-list-mark-upgrade, guix-package-list-mark-upgrades)
  (guix-list-mark-package-upgrades, guix-list-execute-package-actions)
  (guix-package-list-execute, guix-package-list-make-action)
  (guix-package-list-edit, guix-output-list-mark-install)
  (guix-output-list-mark-delete, guix-output-list-mark-upgrade)
  (guix-output-list-mark-upgrades, guix-output-list-make-action)
  (guix-output-list-describe, guix-output-list-edit): Move to
  "guix-ui-package.el".
  (guix-generation-list-get-current, guix-generation-list-switch)
  (guix-generation-list-generations-to-compare)
  (guix-generation-list-compare, guix-generation-list-show-packages)
  (guix-generation-list-show-added-packages)
  (guix-generation-list-show-removed-packages)
  (guix-generation-list-diff, guix-generation-list-diff-manifests)
  (guix-generation-list-ediff, guix-generation-list-ediff-manifests)
  (guix-generation-list-diff-packages)
  (guix-generation-list-ediff-packages)
  (guix-generation-list-mark-delete, guix-generation-list-execute): Move
  to "guix-ui-generation.el".
* emacs/guix.el: Remove.
  (guix, guix-faces, guix-edit): Move to "guix-base.el".
  (guix-list-single-package, guix-search-params, guix-search-history)
  (guix-get-show-packages, guix-search-by-name, guix-search-by-regexp)
  (guix-installed-packages, guix-obsolete-packages)
  (guix-all-available-packages, guix-newest-available-packages): Move
  to "guix-ui-package.el".
  (guix-get-show-generations, guix-generations, guix-last-generations)
  (guix-generations-by-time): Move to "guix-ui-generation.el".
* emacs.am (ELFILES): Remove "guix.el".  Add "guix-ui-package.el" and
  "guix-ui-generation.el".
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-base.el (guix-buffer-name): New procedure.
  (guix-buffer-define-interface): Make ':buffer-name' a required keyword.
  (guix-update-after-operation, guix-buffer-name-function)
  (guix-buffer-name-simple, guix-buffer-name-default, guix-buffer-name)
  (guix-buffer-p, guix-buffers, guix-update-buffer)
  (guix-update-buffers-maybe-after-operation): Adjust, move and rename to...
* emacs/guix-ui.el (guix-ui-update-after-operation)
  (guix-ui-buffer-name-function, guix-ui-buffer-name-simple)
  (guix-ui-buffer-name-default, guix-ui-buffer-name)
  (guix-ui-buffer?, guix-ui-buffers, guix-ui-update-buffer)
  (guix-ui-update-buffers-after-operation): ... this.
  (guix-ui-define-interface): Generate
  'guix-ENTRY-TYPE-BUFFER-TYPE-buffer-name' procedure and pass it as
  ':buffer-name' argument.
  (guix-ui): New custom group.
* emacs/guix-info.el: Specify ':buffer-name' for the defined interfaces.
* emacs/guix-list.el: Likewise.
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-base.el: (guix-root-map): Split into...
  (guix-buffer-map): ... this and...
* emacs/guix-ui.el (guix-ui-map): ... this.
  (guix-ui-define-interface): Generate
  'guix-ENTRY-TYPE-BUFFER-TYPE-mode-map' keymaps inheriting them from
  'guix-ui-map' and 'guix-BUFFER-TYPE-mode-map'.
* emacs/guix-info.el (guix-info-mode-map): Use 'guix-buffer-map'.
* emacs/guix-list.el (guix-list-mode-map): Likewise.
* doc/emacs.texi (Emacs Keymaps): Document new keymaps.

Generate 'guix-ENTRY-TYPE-BUFFER-TYPE-titles' variables for each
ENTRY-TYPE and BUFFER-TYPE instead.

* emacs/guix-base.el (guix-param-titles): Remove.
  (guix-buffer-data): New variable.
  (guix-buffer-value, guix-buffer-param-title): New procedures.
  (guix-buffer-define-interface): Add ':titles' keyword.
* emacs/guix-info.el (guix-info-param-title): Adjust accordingly.
* emacs/guix-list.el (guix-list-param-title): Likewise.
  (guix-list-column-titles): Remove.
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-info.el: Generate 'guix-ENTRY-TYPE-info-format' variables
  for 'package', 'installed-output', 'output' and 'generation' entry
  types.
  (guix-info-format): Remove.
  (guix-info-data): New variable.
  (guix-info-value): New procedure.
  (guix-info-define-interface): Add ':format' keyword.
* emacs/guix-base.el (guix-buffer-define-interface): Add ':reduced?'
  keyword.
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-info.el: Use a more flexible format for inserting any data.
  (guix-info-ignore-empty-vals): Rename to...
  (guix-info-ignore-empty-values): ... this.
  (guix-info-insert-methods): Merge this and...
  (guix-info-displayed-params): ... this into...
  (guix-info-format): ... this.  Change format specifications.
  (guix-info-title-aliases, guix-info-value-aliases): New variables.
  (guix-info-displayed-params): Adjust for the new format.
  (guix-info-insert-entry): Likewise.
  (guix-package-info-fill-heading): Replace with...
  (guix-info-fill): ... this.
  (guix-info-insert-param): Replace with...
  (guix-info-insert-entry-unit): ... this.
  (guix-info-insert-title-default): Replace with...
  (guix-info-insert-title-format): ... this.
  (guix-info-insert-val-default): Replace with...
  (guix-info-insert-value-format): ... this.
  (guix-info-insert-val-simple): Replace with...
  (guix-info-insert-value-indent): ... this.
  (guix-package-info-insert-source): Adjust accordingly.
  (guix-package-info-insert-heading): Insert only name and version.
  (guix-package-info-define-insert-inputs): Do not generate
  'guix-package-info-insert-ENTRY-TYPE-inputs' procedures.
  (guix-info-fill-column, guix-info-insert-entry-default)
  (guix-info-method-funcall, guix-info-insert-file-path)
  (guix-info-insert-url, guix-info-insert-package-function)
  (guix-info-insert-installed-function)
  (guix-info-insert-output-function)
  (guix-info-insert-generation-function)
  (guix-package-info-heading-params)
  (guix-package-info-insert-with-heading)
  (guix-package-info-insert-description)
  (guix-package-info-insert-location)
  (guix-package-info-insert-full-names)
  (guix-package-info-insert-source-url): Remove.
  (guix-info-fill-column, guix-info-param-title)
  (guix-info-title-function, guix-info-value-function)
  (guix-info-title-method->function)
  (guix-info-value-method->function)
  (guix-info-insert-value-simple): New procedures.
* emacs/guix-utils.el (guix-buttonize, guix-button-type?): New
  procedures.
  (guix-split-string): Split multi-line strings and ignore empty lines.
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-list.el: Generate 'guix-ENTRY-TYPE-list-format' variables
  for 'package', 'output' and 'generation' entry types.
  (guix-list-format): Remove.
  (guix-list-define-entry-type): Add ':format' keyword.
* doc/emacs.texi (Emacs Appearance): Adjust accordingly.

* emacs/guix-list.el: (guix-list-column-format): Merge this and...
  (guix-list-column-value-methods): ... this into...
  (guix-list-format): ... this.  New variable.
  (guix-list-tabulated-vector): Adjust accordingly.
  (guix-list-tabulated-format): Likewise.
  (guix-list-tabulated-entry): Likewise.
* doc/emacs.texi (Emacs Appearance): Likewise.

* emacs/guix-build-log.el (guix-build-log-minor-mode-activate): New variable.
  (guix-build-log-minor-mode-activate-maybe): New function.
* emacs/guix-init.el: Add it to 'shell-mode-hook'.
* doc/emacs.texi (Emacs Build Log): Mention it.

* emacs/guix-build-log.el (guix-build-log-mode-map): Move keys to ...
  (guix-build-log-common-map): ...here.  New variable.
  (guix-build-log-minor-mode-map): New variable.
  (guix-build-log-minor-mode): Use it.
* doc/emacs.texi (Emacs Build Log): Document it.

* doc/contributing.texi (Running Guix Before It Is Installed): Add REPL
  example.
* doc/emacs.texi (Emacs General info): Add @cindex.

* doc/emacs.texi (Emacs Popup Interface): Document "View graph" action.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* guix/scripts.scm (build-package-source): New procedure.
* emacs/guix-devel.el (guix-devel-build-package-source): New command.
  (guix-devel-keys-map): Add key binding for it.
* doc/emacs.texi (Emacs Development): Document it.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-devel.el (guix-devel-setup-repl): Add a workaround for
  'guix-warning-port'.
  (guix-devel-lint-package): New command.
  (guix-devel-keys-map): Add key binding for it.
* doc/emacs.texi (Emacs Development): Document it.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-guile.el (guix-guile-definition-regexp): New variable.
  (guix-guile-current-definition, guix-guile-boolean): New functions.
* emacs/guix-devel.el: Require 'guix-base'.
  (guix-devel-repl-processes): New variable.
  (guix-devel-setup-repl, guix-devel-setup-repl-maybe): New functions.
  (guix-devel-build-package-definition): New command.
* doc/emacs.texi (Emacs Development): Document it.

* emacs/guix-guile.el (guix-guile-current-module): New function.
* emacs/guix-devel.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Development): New node.
  (Emacs Interface): Add it.
* doc/contributing.texi (The Perfect Setup): Mention it.
* doc/guix.texi (Top): Add it.
* emacs/guix-init.el: Add 'guix-devel-activate-mode-maybe' to
  'scheme-mode-hook'.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-build-log.el (guix-build-log-phase-end-regexp): New
  variable.
  (guix-build-log-phase-start, guix-build-log-phase-end,
  guix-build-log-phase-hide, guix-build-log-phase-show,
  guix-build-log-phase-hidden-p, guix-build-log-phase-toggle-function,
  guix-build-log-phase-toggle, guix-build-log-phase-toggle-all): New functions.
  (guix-build-log-mode-map): Add 'TAB'/'S-TAB' key bindings.
* doc/emacs.texi (Emacs Build Log): Document them.

* emacs/guix-build-log.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Build Log): Document it.  New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Likewise.

* emacs/guix-command.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Initial Setup): Mention 'magit-popup' library.
  (Emacs Popup Interface): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Likewise.

* doc/guix.texi (Package Management): Move "Emacs Interface" node to ...
  (Top): ...here, since it is not just about package management.
* doc/emacs.texi: Shift all nodes one level up (@section -> @chapter, etc.).
  Rename "Emacs Usage" node into "Emacs Package Management".  Move "Emacs
  Configuration" node here.