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.

doc/emacs.texi

@@ -484,13 +484,12 @@ the following variables (@dfn{ENTRY-TYPE} means @code{package},
 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
+@item guix-info-format
+@itemx guix-info-ignore-empty-values
 @itemx guix-info-param-title-format
 @itemx guix-info-multiline-prefix
 @itemx guix-info-indent
-@itemx guix-info-fill-column
+@itemx guix-info-fill
 @itemx guix-info-delimiter
 Various settings for ``info'' buffers.
 

emacs/guix-utils.el

@@ -104,6 +104,28 @@ See `insert-text-button' for the meaning of PROPERTIES."
            :type (or type 'button)
            properties)))
 
+(defun guix-buttonize (value button-type separator &rest properties)
+  "Make BUTTON-TYPE button(s) from VALUE.
+Return a string with button(s).
+
+VALUE should be a string or a list of strings.  If it is a list
+of strings, buttons are separated with SEPARATOR string.
+
+PROPERTIES are passed to `guix-insert-button'."
+  (with-temp-buffer
+    (let ((labels (if (listp value) value (list value))))
+      (guix-mapinsert (lambda (label)
+                        (apply #'guix-insert-button
+                               label button-type properties))
+                      labels
+                      separator))
+    (buffer-substring (point-min) (point-max))))
+
+(defun guix-button-type? (symbol)
+  "Return non-nil, if SYMBOL is a button type."
+  (and symbol
+       (get symbol 'button-category-symbol)))
+
 (defun guix-split-insert (val &optional face col separator)
   "Convert VAL into a string, split it and insert at point.
 
@@ -122,14 +144,11 @@ Separate inserted lines with 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)))
+If COL is non-nil, fill STR to this column."
+  (let ((str (if col
+                 (guix-get-filled-string str col)
+               str)))
+    (split-string str "\n *" t)))
 
 (defun guix-get-filled-string (str col)
   "Return string by filling STR to column COL."