From d38394e5d54fe1c7997634bb2ebd966a36a52f82 Mon Sep 17 00:00:00 2001
From: Robert Pluim <rpluim@gmail.com>
Date: Tue, 5 Feb 2019 20:38:39 +0100
Subject: [PATCH] Add dwim function for inserting @ref variants
To: emacs-devel@gnu.org

* lisp/textmodes/texinfo.el (texinfo-insert-dwim-@ref): New function.
Insert @ref variant based on surrounding context.
(texinfo-mode-map): Add binding for texinfo-insert-dwim-@ref.

* etc/NEWS: Describe new texinfo dwim reference functionality.
---
 etc/NEWS                  |  9 +++++++++
 lisp/textmodes/texinfo.el | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/etc/NEWS b/etc/NEWS
index 9bbe6befcf..5c06edd00a 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -472,6 +472,15 @@ To enable it, set the new defcustom 'diff-font-lock-prettify' to t.
 of the file under version control if point is on an old changed line,
 or to the new revision of the file otherwise.
 
+** Texinfo
+
++++
+*** New function for inserting @pxref, @xref, or @ref commands.
+The function 'texinfo-insert-dwim-@ref', bound to 'C-c C-c r' by
+default, inserts one of three types of references based on the text
+surrounding point, namely @pxref near a parenthesis, @xref at the
+start of a sentence or at (point-min), else @ref.
+
 ** Browse-url
 
 *** The function 'browse-url-emacs' can now visit a URL in selected window.
diff --git a/lisp/textmodes/texinfo.el b/lisp/textmodes/texinfo.el
index 1a900122f9..71cdcab57e 100644
--- a/lisp/textmodes/texinfo.el
+++ b/lisp/textmodes/texinfo.el
@@ -470,6 +470,7 @@ texinfo-mode-map
     (define-key map "\C-c\C-cu"    'texinfo-insert-@uref)
     (define-key map "\C-c\C-ct"    'texinfo-insert-@table)
     (define-key map "\C-c\C-cs"    'texinfo-insert-@samp)
+    (define-key map "\C-c\C-cr"    'texinfo-insert-dwim-@ref)
     (define-key map "\C-c\C-cq"    'texinfo-insert-@quotation)
     (define-key map "\C-c\C-co"    'texinfo-insert-@noindent)
     (define-key map "\C-c\C-cn"    'texinfo-insert-@node)
@@ -825,6 +826,38 @@ texinfo-insert-@quotation
   "Insert the string `@quotation' in a Texinfo buffer."
   \n "@quotation" \n _ \n)
 
+(define-skeleton texinfo-insert-dwim-@ref
+  "Insert appropriate `@pxref{...}', `@xref{}', or `@ref{}' command.
+
+Looks at text around point to decide what to insert; an unclosed
+preceding open parenthesis results in '@pxref{}', point at the
+beginning of a sentence or at (point-min) yields '@xref{}', any
+other location (including inside a word), will result in '@ref{}'
+at the nearest previous whitespace or beginning-of-line.  A
+numeric argument says how many words the braces should surround.
+The default is not to surround any existing words with the
+braces."
+  nil
+  (cond
+   ;; parenthesis
+   ((looking-back "([^)]*" (point-at-bol 0))
+    "@pxref{")
+   ;; beginning of sentence or buffer
+   ((or (looking-back (sentence-end) (point-at-bol 0))
+        (= (point) (point-min)))
+    "@xref{")
+   ;; bol or eol
+   ((looking-at "^\\|$")
+    "@ref{")
+   ;; inside word
+   ((not (eq (char-syntax (char-after)) ? ))
+    (skip-syntax-backward "^ " (point-at-bol))
+    "@ref{")
+   ;; everything else
+   (t
+    "@ref{"))
+  _ "}")
+
 (define-skeleton texinfo-insert-@samp
   "Insert a `@samp{...}' command in a Texinfo buffer.
 A numeric argument says how many words the braces should surround.
-- 
2.20.1.142.g77556354bb