Add more functionality to help

README.org

@@ -284,6 +284,7 @@ of [[info:emacs#Saving Customizations][saving customizations (info)]].
                             (consult . "gnu")
                             (dash . "melpa-stable")
                             (debbugs . "gnu")
+                            (denote . "gnu")
                             (eldoc . "nongnu")
                             (embark . "gnu")
                             (embark-consult . "gnu")
@@ -1004,9 +1005,19 @@ output to =stdout=.
 :CUSTOM_ID: sec:help
 :END:
 
-Table [[tab:help-key-bindings]] lists a number of key bindings to start playing with
-the help facilities of Emacs.  Try {{{kbd(C-h o)}}} instead of {{{kbd(C-h f)}}}
-or {{{kbd(C-h v)}}}.
+Listing [[lst:setup-help]] enriches the help buffer.  Table [[tab:help-key-bindings]]
+lists a number of key bindings to start playing with the help facilities of
+Emacs.  Try {{{kbd(C-h o)}}} instead of {{{kbd(C-h f)}}} or {{{kbd(C-h v)}}}.
+
+#+caption[Setup =help=]:
+#+caption: Setup =help=.
+#+name: lst:setup-help
+#+begin_src emacs-lisp -n :results silent
+(with-eval-after-load 'help-fns
+  (add-hook 'help-fns-describe-function-functions
+            #'shortdoc-help-fns-examples-function)
+  (setopt help-enable-symbol-autoload t))
+#+end_src
 
 #+attr_latex: :booktabs yes :float table
 #+caption[Help key bindings]:
@@ -1023,18 +1034,6 @@ or {{{kbd(C-h v)}}}.
 | info                         | help-map | {{{kbd(C-h i)}}} |
 |------------------------------+----------+------------------|
 
-#+begin_src emacs-lisp -n :exports none :results silent :tangle no
-(defun org-key-binding-macro (cmd)
-  (let* ((sym (intern-soft cmd))
-         (keys (and (commandp sym) (where-is-internal sym nil 'first-only)))
-         (prefix (seq-take keys (1- (length keys))))
-         (keymap (key-binding prefix 'accept-default)))
-    (format "%s %s %s {{{kbd(%s)}}}"
-            cmd keymap (help--binding-locus keys nil) (key-description keys))))
-
-(org-key-binding-macro 'consult-buffer)
-#+end_src
-
 ** [[info:emacs#Name Help][Shortdoc-display-group (info)]]
 :PROPERTIES:
 :CUSTOM_ID: sec:shortdoc-display-group
@@ -1561,6 +1560,9 @@ Consult usage tips are:
    consult-mark)}}} or {{{kbd(M-g m)}}}.  See [[https://arialdomartini.github.io//emacs-mark-ring][Emacs: Mark Ring]].
 2. {{{kbd(M-x consult-org-heading)}}} or {{{kbd(C-c C-h)}}} is an alternative to
    {{{kbd(M-x org-goto)}}} or {{{kbd(C-c C-j)}}}.
+3. Listing [[lst:find-file-preview]] uses the internal functions
+ ~consult--file-preview~ and ~consult--read~ to visit files with previewing
+   during selection. See: [[https://github.com/minad/consult/wiki][Consult Wiki]].
 
 #+attr_latex: :booktabs yes :float table
 #+caption[Configuration specific key bindings]:
@@ -1646,6 +1648,29 @@ Consult usage tips are:
   (keymap-global-set "M-y" #'consult-yank-pop))
 #+end_src
 
+#+caption[Implement =find-file= with previewing before selection]:
+#+caption: Implement =find-file= with previewing before selection.
+#+name: lst:find-file-preview
+#+begin_src emacs-lisp -n :results silent
+(defun consult-find-file-preview(cue &optional dir default mustmatch init pred)
+  (interactive)
+  (let ((default-directory (or dir default-directory))
+        (minibuffer-completing-file-name t))
+    (consult--read #'read-file-name-internal :state (consult--file-preview)
+                   :prompt cue :initial init
+                   :require-match mustmatch :predicate pred)))
+
+(defun toggle-find-file-preview ()
+  "Toggle previewing when calling `find-file'."
+  (interactive)
+  (let ((done "Enabled"))
+    (if (eq read-file-name-function #'read-file-name-default)
+        (setq read-file-name-function #'consult-find-file-preview)
+      (setq read-file-name-function #'read-file-name-default
+            done "Disabled"))
+    (message "%s `find-file' previewing" done)))
+#+end_src
+
 ** [[https://company-mode.github.io/][Company (info)]]
 :PROPERTIES:
 :CUSTOM_ID: sec:company-setup