emacs: Split 'guix-root-map' keymap.

* 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.

emacs: Add wrappers for 'history-size' and 'revert-confirm'.

* emacs/guix-base.el (guix-buffer-history-size): New procedure.
  (guix-buffer-define-interface): Use it in the mode definition.
  (guix-buffer-revert-confirm?): New procedure.
  (guix-revert-buffer): Use it.

emacs: Split 'guix-param-titles' variable.

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: info: Split 'guix-info-format' variable.

* 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: Factorize macros for defining interfaces.

Make a root 'guix-buffer-define-interface' macro.  It should generate a
common code for any type of interface.  Inherit 'guix-info-define-interface'
and 'guix-list-define-interface' from it.  They should provide a general
'info'/'list' interface for any data.  Finally, make
'guix-ui-define-interface' for the common code for interfaces to Guix
packages and generations, and inherit 'guix-ui-info-define-interface' and
'guix-ui-list-define-interface' from it.

* emacs/guix-base.el (guix-define-buffer-type): Rename to...
  (guix-buffer-define-interface): ... this.  Rename internal
  variables ('buf-' -> 'buffer-').  Move ':required' keyword to
  'guix-ui-define-interface'.
* emacs/guix-info.el (guix-info-define-interface): New macro.
  (guix-info-font-lock-keywords): New variable.
* emacs/guix-list.el (guix-list-define-entry-type): Rename to...
  (guix-list-define-interface): ... this.
  (guix-list-font-lock-keywords): New variable.
  (guix-list-describe-ids): Move and rename to...
* emacs/guix-ui.el: New file.
  (guix-ui-list-describe): ... this.
  (guix-ui-define-interface, guix-ui-info-define-interface)
  (guix-ui-list-define-interface): New macros.
  (guix-ui-font-lock-keywords): New variable.
* emacs.am (ELFILES): Add "emacs/guix-ui.el"

emacs: info: Generalize inserting and formatting.

* 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: list: Factorize "edit package" commands.

* emacs/guix-list.el: Use separate edit commands instead of a single one.
  (guix-list-for-each-line, guix-list-edit-package): Remove.
  (guix-package-list-edit, guix-output-list-edit): New procedures.
  (guix-package-list-mode-map, guix-output-list-mode-map): Use them.

emacs: list: Split 'guix-list-format' variable.

* 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: list: Add 'guix-list-mode-initialize'.

* emacs/guix-list.el (guix-list-mode-initialize): New procedure.
  (guix-list-define-entry-type): Use it.

emacs: list: Generalize 'sort-key' code.

* emacs/guix-list.el (guix-list-sort-key): New procedure.
  (guix-list-tabulated-sort-key): Use it.
  (guix-list-define-entry-type): Generate
  'guix-ENTRY-TYPE-list-sort-key' variables.

emacs: list: Generalize 'describe' code.

* emacs/guix-list.el (guix-list-describe-warning-count): Remove variable.
  (guix-list-define-entry-type): Generate
  'guix-ENTRY-TYPE-list-describe-warning-count' and
  'guix-ENTRY-TYPE-list-describe-function' variables.
  (guix-list-describe-maybe): Remove.  Move the code...
  (guix-list-describe): ... here.
  (guix-list-describe-warning-count, guix-list-describe-entries)
  (guix-list-describe-ids): New procedures.
  (guix-output-list-describe): Adjust accordingly.
  (guix-list-mode-map): Bind "i" key to 'guix-list-describe'.
  (guix-generation-list-mode-map): Remove "i" key.

emacs: list: Generalize 'marks' code.

* emacs/guix-list.el (guix-list-mark-alist): Rename to...
  (guix-list-marks): ... this
  (guix-list-data, guix-list-default-marks): New variables.
  (guix-list-value, guix-list-additional-marks, guix-list-marks): New
  procedures.
  (guix-list-define-entry-type): Adjust accordingly.

emacs: Add 'guix-alist-put'.

* emacs/guix-utils.el (guix-alist-put, guix-alist-put-1)
  (guix-alist-put!): New procedures.

emacs: Add 'guix-keyword-args-let'.

* emacs/guix-utils.el (guix-keyword-args-let): New macro.
  (guix-utils-font-lock-keywords): Add it.
* emacs/guix-base.el (guix-define-buffer-type): Use it.
* emacs/guix-list.el (guix-list-define-entry-type): Use it.
* emacs/guix-read.el (guix-define-readers): Use it.

emacs: list: Configure format in one place.

* 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: Rename internal procedures.

* emacs/guix-list.el (guix-list-get-param-title): Rename to...
  (guix-list-param-title): ... this.
  (guix-list-get-column-format): Rename to...
  (guix-list-format): ... this.
  (guix-list-get-displayed-params): Rename to...
  (guix-list-displayed-params): ... this.
  (guix-list-get-sort-key): Rename to...
  (guix-list-tabulated-sort-key): ... this.
  (guix-list-make-tabulated-vector): Rename to...
  (guix-list-tabulated-vector): ... this.
  (guix-list-get-list-format): Rename to...
  (guix-list-tabulated-format): ... this.
  (guix-list-get-tabulated-entries): Rename to...
  (guix-list-tabulated-entries): ... this.
  (guix-list-get-tabulated-entry): Rename to...
  (guix-list-tabulated-entry): ... this.
* emacs/guix-info.el (guix-info-get-displayed-params): Rename to...
  (guix-info-displayed-params): ... this.
* emacs/guix-base.el (guix-get-params-for-receiving): Adjust
  accordingly.
  (guix-get-name-spec): Rename to...
  (guix-package-name-specification): ... this.
  (guix-get-full-name): Merge this and...
  (guix-entry-to-specification): ... this into...
  (guix-package-entry->name-specification): ... this.
  (guix-get-installed-outputs): Rename to...
  (guix-package-installed-outputs): ... this.
  (guix-get-package-id-and-output-by-output-id): Rename to...
  (guix-package-id-and-output-by-output-id): ... this.

emacs: list: Generate numerical sort predicates.

* emacs/guix-list.el: Generate predicates to sort tabulated list
  columns numerically.
  (guix-list-define-numerical-sorter)
  (guix-list-define-numerical-sorters): New macros
  (guix-list-column-format): Use 'guix-list-sort-numerically-0' for
  generation "Number" column.

emacs: Simplify defining parameter titles.

* emacs/guix-utils.el (guix-symbol-title): New procedure.
* emacs/guix-base.el (guix-get-param-title): Use it.
  (guix-param-titles): Remove most titles as they are automatically
  defined by 'guix-symbol-title'.

emacs: Add API for 'guix-entry'.

* emacs/guix-info.el: Use new entry procedures.
* emacs/guix-list.el: Likewise.
* emacs/guix-base.el: Likewise.
  (guix-get-entry-by-id): Move and rename to ...
* emacs/guix-entry.el (guix-entry-by-id): ...this.  New file.
  (guix-entry-value, guix-entry-id, guix-entries-by-ids)
  (guix-replace-entry): New procedures.
* emacs.am (ELFILES): Add new file.

emacs: Add 'guix-with-indent'.

* emacs/guix-utils.el (guix-with-indent): New macro.
  (guix-memoized-font-lock-keywords): Rename to...
  (guix-utils-font-lock-keywords): ... this.  Add it.
* emacs/guix-info.el (guix-info-insert-entry-default): Use it.