Re: [PATCH] Enable customisation for electric-quote-mode chars

[Göktuğ Kayaalp]

On Paz, Ağu 28 2016 at 06:55:06 PM, Paul Eggert <address@hidden> wrote:
> Göktuğ Kayaalp wrote:
> [...]
>
> * Part of the code still assumes English-style single quoting, and won't work 
> if 
> electric-quote-chars is set appropriately for (say) French. Look for 
> instances 
> of the two characters ‘ and ’ in the string constants. More generally, I'd 
> look 
> for any non-ASCII character in that file.
>
> * The documentation should say "curved" rather than "curvy" for consistency 
> with 
> what's there now.
>
> * The documentation is a bit sloppy about which quotes are used for what, 
> e.g., 
> "the first two are used for left single quotes" is not correct and the doc 
> string is a bit hard to follow. For the documentation I suggest specifying 
> the 
> default value in the manual, as that should make it easier to explain the 
> format 
> of the variable.
>
> * Perhaps use pcase instead of 4 calls to nth? It'd make the code easier to 
> read.

All done, I hope that's okay to apply now.  The new patch is attached.
I'll try to improve it if need be.

> * Finally, it's a nontrivial patch so I assume you're OK with assigning 
> copyright to the FSF? If so, I can start the ball rolling on the paperwork 
> for you.

Allright, I'm okay with that, please go ahead.  BTW I also have a patch
submitted recently to the bug-gnu-emacs@ for bug#24082, should I post it
here instead?

> Thanks again.

You're welcome, I'm glad if this is helpful.

-- 
İ. Göktuğ Kayaalp.
http://gkayaalp.com/

diff --git a/doc/emacs/text.texi b/doc/emacs/text.texi
index 579f788..74b68dd 100644
--- a/doc/emacs/text.texi
+++ b/doc/emacs/text.texi
@@ -412,6 +412,7 @@ beginning of a line.
 @cindex mode, Electric Quote
 @cindex curly quotes
 @cindex curved quotes
address@hidden guillemets
 @findex electric-quote-mode
   One common way to quote is the typewriter convention, which quotes
 using straight apostrophes @t{'like this'} or double-quotes @t{"like
@@ -420,11 +421,17 @@ left and right single or double quotation marks @t{‘like 
this’} or
 @t{“like this”}.  In text files, typewriter quotes are simple and
 portable; curved quotes are less ambiguous and typically look nicer.
 
address@hidden electric-quote-chars
   Electric Quote mode makes it easier to type curved quotes.  As you
 type characters it optionally converts @t{`} to @t{‘}, @t{'} to @t{’},
 @t{``} to @t{“}, and @t{''} to @t{”}.  These conversions are
 suppressed in buffers whose coding systems cannot represent curved
-quote characters.
+quote characters.  It's possible to change the default quotes listed
+above, by customizing the variable @code{electric-quote-chars}, a list
+of four characters, where the items correspond to the left single
+quote, the right single quote, the left double quote and the right
+double quote, respectively, whose default value is
address@hidden'(?‘ ?’ ?“ ?”)}.
 
 @vindex electric-quote-paragraph
 @vindex electric-quote-comment
@@ -445,7 +452,10 @@ type @kbd{C-q `} or @kbd{C-q '} instead of @kbd{`} or 
@kbd{'}.  To
 insert a curved quote even when Electric Quote is disabled or
 inactive, you can type @kbd{C-x 8 [} for @t{‘}, @kbd{C-x 8 ]} for
 @t{’}, @kbd{C-x 8 @{} for @t{“}, and @kbd{C-x 8 @}} for @t{”}.
address@hidden Text}.
address@hidden Text}.  Note that the value of
address@hidden does not affect these keybindings, they
+are not keybindings of @code{electric-quote-mode} but bound in
address@hidden
 
 @node Filling
 @section Filling Text
diff --git a/etc/NEWS b/etc/NEWS
index 1290fa4..e7682fb 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -56,6 +56,11 @@ affected by this, as SGI stopped supporting IRIX in December 
2013.
 * Changes in Emacs 25.2
 
 +++
+** The new user variable 'electric-quote-chars' provides a list
+of curved quotes for 'electric-quote-mode', allowing user to choose
+the types of quotes to be used.
+
++++
 ** The new funtion 'call-shell-region' executes a command in an
 inferior shell with the buffer region as input.
 
diff --git a/lisp/electric.el b/lisp/electric.el
index e289601..c0c4b47 100644
--- a/lisp/electric.el
+++ b/lisp/electric.el
@@ -425,16 +425,26 @@ The variable `electric-layout-rules' says when and how to 
insert newlines."
   :version "25.1"
   :type 'boolean :safe 'booleanp :group 'electricity)
 
+(defcustom electric-quote-chars '(?‘ ?’ ?“ ?”)
+  "Curved quote characters for `electric-quote-mode'.
+The items correspond to the left single quote, the right single
+quote, the left double quote, and the right double quote, respectively."
+  :version "25.1"
+  :type 'list :safe 'listp :group 'electricity)
+
 (defcustom electric-quote-paragraph t
   "Non-nil means to use electric quoting in text paragraphs."
   :version "25.1"
   :type 'boolean :safe 'booleanp :group 'electricity)
 
-(defun electric--insertable-p (string)
-  (or (not buffer-file-coding-system)
-      (eq (coding-system-base buffer-file-coding-system) 'undecided)
-      (not (unencodable-char-position nil nil buffer-file-coding-system
-                                      nil string))))
+(defun electric--insertable-p (string-or-char)
+  (let ((str (if (characterp string-or-char)
+                 (string string-or-char)
+               string-or-char)))
+    (or (not buffer-file-coding-system)
+        (eq (coding-system-base buffer-file-coding-system) 'undecided)
+        (not (unencodable-char-position nil nil buffer-file-coding-system
+                                        nil str)))))
 
 (defun electric-quote-post-self-insert-function ()
   "Function that `electric-quote-mode' adds to `post-self-insert-hook'.
@@ -457,30 +467,33 @@ This requotes when a quoting key is typed."
                   (derived-mode-p 'text-mode)
                   (or (eq last-command-event ?\`)
                       (save-excursion (backward-paragraph) (point)))))))
-      (when start
-        (save-excursion
-          (if (eq last-command-event ?\`)
-              (cond ((and (electric--insertable-p "“")
-                          (search-backward "‘`" (- (point) 2) t))
-                     (replace-match "“")
-                     (when (and electric-pair-mode
-                                (eq (cdr-safe
-                                     (assq ?‘ electric-pair-text-pairs))
-                                    (char-after)))
-                       (delete-char 1))
-                     (setq last-command-event ?“))
-                    ((and (electric--insertable-p "‘")
-                          (search-backward "`" (1- (point)) t))
-                     (replace-match "‘")
-                     (setq last-command-event ?‘)))
-            (cond ((and (electric--insertable-p "”")
-                        (search-backward "’'" (- (point) 2) t))
-                   (replace-match "”")
-                   (setq last-command-event ?”))
-                  ((and (electric--insertable-p "’")
-                        (search-backward "'" (1- (point)) t))
-                   (replace-match "’")
-                   (setq last-command-event ?’)))))))))
+      (pcase electric-quote-chars
+        (`(,q1 ,q2 ,q3 ,q4) 
+         (when start
+           (save-excursion
+             (if (eq last-command-event ?\`)
+                 (cond ((and (electric--insertable-p q3)
+                             (search-backward (string q1 ?`) (- (point) 2) t))
+                        (replace-match (string q3))
+                        (when (and electric-pair-mode
+                                   (eq (cdr-safe
+                                        (assq q1 electric-pair-text-pairs))
+                                       (char-after)))
+                          (delete-char 1))
+                        (setq last-command-event q3))
+                       ((and (electric--insertable-p q1)
+                             (search-backward "`" (1- (point)) t))
+                        (replace-match (string q1))
+                        (setq last-command-event q1)))
+               (cond ((and (electric--insertable-p q4)
+                           (search-backward (string q2 ?') (- (point) 2) t))
+                      (replace-match (string q4))
+                      (setq last-command-event q4))
+                     ((and (electric--insertable-p q2)
+                           (search-backward "'" (1- (point)) t))
+                      (replace-match (string q2))
+                      (setq last-command-event q2)))))))
+        (_ (error "‘electric-quote-chars’ must contain exactly 4 
characters."))))))
 
 (put 'electric-quote-post-self-insert-function 'priority 10)
 
@@ -497,6 +510,9 @@ and text paragraphs, and these are selectively controlled 
with
 `electric-quote-comment', `electric-quote-string', and
 `electric-quote-paragraph'.
 
+Customize `electric-quote-chars' in order to use quote chars
+other than the ones listed here.
+
 This is a global minor mode.  To toggle the mode in a single buffer,
 use `electric-quote-local-mode'."
   :global t :group 'electricity