Make Electric Pair mode smarter/more useful:

* lisp/electric.el: Pairing/skipping helps preserve
  balance. Autobackspacing behaviour. Opens extra newlines between
  pairs. Skip whitespace before closing delimiters.

* lisp/emacs-lisp/lisp-mode.el (lisp-mode-variables): Use new
  features.

* test/automated/electric-tests.lisp: New file.

* doc/emacs/programs.texi: Describe new features.

* lisp/simple.el: Pass non-nil interactive arg to newline call inside
  newline-and-indent.

4 files changed, 542 insertions, 95 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 972106bd26f..2831988efd9 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,25 @@
+2013-12-26  João Távora <joaotavora@gmail.com>
+
+        * electric.el (electric-pair-mode): More flexible engine for skip-
+        and inhibit predicates, new options for pairing-related
+        functionality.
+        (electric-pair-preserve-balance): Pair/skip parentheses and quotes
+        if that keeps or improves their balance in buffers.
+        (electric-pair-delete-adjacent-pairs): Delete the pair when
+        backspacing over adjacent matched delimiters.
+        (electric-pair-open-extra-newline): Open extra newline when
+        inserting newlines between adjacent matched delimiters.
+        (electric--sort-post-self-insertion-hook): Sort
+        post-self-insert-hook according to priority values when
+        minor-modes are activated.
+        * simple.el (newline-and-indent): Call newline with interactive
+        set to t.
+        (blink-paren-post-self-insert-function): Set priority to 100.
+        * emacs-lisp/lisp-mode.el (lisp-mode-variables): Use
+        electric-pair-text-pairs to pair backtick-and-quote in strings and
+        comments. Locally set electric-pair-skip-whitespace to 'chomp and
+        electric-pair-open-newline-between-pairs to nil.
+
 2013-12-26  Fabián Ezequiel Gallina  <fgallina@gnu.org>
 
         * progmodes/python.el: Use lexical-binding.
diff --git a/lisp/electric.el b/lisp/electric.el
index 91b99b4bfe7..fc5e63f90bb 100644
--- a/lisp/electric.el
+++ b/lisp/electric.el
@@ -187,6 +187,17 @@ Returns nil when we can't find this char."
                            (eq (char-before) last-command-event)))))
       pos)))
 
+(defun electric--sort-post-self-insertion-hook ()
+  "Ensure order of electric functions in `post-self-insertion-hook'.
+
+Hooks in this variable interact in non-trivial ways, so a
+relative order must be maintained within it."
+  (setq-default post-self-insert-hook
+                (sort (default-value 'post-self-insert-hook)
+                      #'(lambda (fn1 fn2)
+                          (< (or (get fn1 'priority) 0)
+                             (or (get fn2 'priority) 0))))))
+
 ;;; Electric indentation.
 
 ;; Autoloading variables is generally undesirable, but major modes
@@ -267,6 +278,8 @@ mode set `electric-indent-inhibit', but this can be used as a workaround.")
                    (> pos (line-beginning-position)))
         (indent-according-to-mode)))))
 
+(put 'electric-indent-post-self-insert-function 'priority  60)
+
 (defun electric-indent-just-newline (arg)
   "Insert just a newline, without any auto-indentation."
   (interactive "*P")
@@ -295,20 +308,9 @@ insert a character from `electric-indent-chars'."
                      #'electric-indent-post-self-insert-function))
     (when (eq (lookup-key global-map [?\C-j]) 'newline-and-indent)
       (define-key global-map [?\C-j] 'electric-indent-just-newline))
-    ;; post-self-insert-hooks interact in non-trivial ways.
-    ;; It turns out that electric-indent-mode generally works better if run
-    ;; late, but still before blink-paren.
     (add-hook 'post-self-insert-hook
-              #'electric-indent-post-self-insert-function
-              'append)
-    ;; FIXME: Ugly!
-    (let ((bp (memq #'blink-paren-post-self-insert-function
-                    (default-value 'post-self-insert-hook))))
-      (when (memq #'electric-indent-post-self-insert-function bp)
-        (setcar bp #'electric-indent-post-self-insert-function)
-        (setcdr bp (cons #'blink-paren-post-self-insert-function
-                         (delq #'electric-indent-post-self-insert-function
-                               (cdr bp))))))))
+              #'electric-indent-post-self-insert-function)
+    (electric--sort-post-self-insertion-hook)))
 
 ;;;###autoload
 (define-minor-mode electric-indent-local-mode
@@ -327,32 +329,163 @@ insert a character from `electric-indent-chars'."
 
 (defcustom electric-pair-pairs
   '((?\" . ?\"))
-  "Alist of pairs that should be used regardless of major mode."
+  "Alist of pairs that should be used regardless of major mode.
+
+Pairs of delimiters in this list are a fallback in case they have
+no syntax relevant to `electric-pair-mode' in the mode's syntax
+table.
+
+See also the variable `electric-pair-text-pairs'."
   :version "24.1"
   :type '(repeat (cons character character)))
 
-(defcustom electric-pair-skip-self t
+(defcustom electric-pair-text-pairs
+  '((?\" . ?\" ))
+  "Alist of pairs that should always be used in comments and strings.
+
+Pairs of delimiters in this list are a fallback in case they have
+no syntax relevant to `electric-pair-mode' in the syntax table
+defined in `electric-pair-text-syntax-table'"
+  :version "24.4"
+  :type '(repeat (cons character character)))
+
+(defcustom electric-pair-skip-self #'electric-pair-default-skip-self
   "If non-nil, skip char instead of inserting a second closing paren.
+
 When inserting a closing paren character right before the same character,
 just skip that character instead, so that hitting ( followed by ) results
 in \"()\" rather than \"())\".
-This can be convenient for people who find it easier to hit ) than C-f."
+
+This can be convenient for people who find it easier to hit ) than C-f.
+
+Can also be a function of one argument (the closer char just
+inserted), in which case that function's return value is
+considered instead."
   :version "24.1"
-  :type 'boolean)
+  :type '(choice
+          (const :tag "Never skip" nil)
+          (const :tag "Help balance" electric-pair-default-skip-self)
+          (const :tag "Always skip" t)
+          function))
 
 (defcustom electric-pair-inhibit-predicate
   #'electric-pair-default-inhibit
   "Predicate to prevent insertion of a matching pair.
+
 The function is called with a single char (the opening char just inserted).
 If it returns non-nil, then `electric-pair-mode' will not insert a matching
 closer."
   :version "24.4"
   :type '(choice
-          (const :tag "Default" electric-pair-default-inhibit)
+          (const :tag "Conservative" electric-pair-conservative-inhibit)
+          (const :tag "Help balance" electric-pair-default-inhibit)
           (const :tag "Always pair" ignore)
           function))
 
-(defun electric-pair-default-inhibit (char)
+(defcustom electric-pair-preserve-balance t
+  "Non-nil if default pairing and skipping should help balance parentheses.
+
+The default values of `electric-pair-inhibit-predicate' and
+`electric-pair-skip-self' check this variable before delegating to other
+predicates reponsible for making decisions on whether to pair/skip some
+characters based on the actual state of the buffer's parenthesis and
+quotes."
+  :version "24.4"
+  :type 'boolean)
+
+(defcustom electric-pair-delete-adjacent-pairs t
+  "If non-nil, backspacing an open paren also deletes adjacent closer.
+
+Can also be a function of no arguments, in which case that function's
+return value is considered instead."
+  :version "24.4"
+  :type '(choice
+          (const :tag "Yes" t)
+          (const :tag "No" nil)
+          function))
+
+(defcustom electric-pair-open-newline-between-pairs t
+  "If non-nil, a newline between adjacent parentheses opens an extra one.
+
+Can also be a function of no arguments, in which case that function's
+return value is considered instead."
+  :version "24.4"
+  :type '(choice
+          (const :tag "Yes" t)
+          (const :tag "No" nil)
+          function))
+
+(defcustom electric-pair-skip-whitespace t
+  "If non-nil skip whitespace when skipping over closing parens.
+
+The specific kind of whitespace skipped is given by the variable
+`electric-pair-skip-whitespace-chars'.
+
+The symbol `chomp' specifies that the skipped-over whitespace
+should be deleted.
+
+Can also be a function of no arguments, in which case that function's
+return value is considered instead."
+  :version "24.4"
+  :type '(choice
+          (const :tag "Yes, jump over whitespace" t)
+          (const :tag "Yes, and delete whitespace" 'chomp)
+          (const :tag "No, no whitespace skipping" nil)
+          function))
+
+(defcustom electric-pair-skip-whitespace-chars (list ?\t ?\s ?\n)
+  "Whitespace characters considered by `electric-pair-skip-whitespace'."
+  :version "24.4"
+  :type '(choice (set (const :tag "Space" ?\s)
+                      (const :tag "Tab" ?\t)
+                      (const :tag "Newline" ?\n))
+                 (list character)))
+
+(defun electric-pair--skip-whitespace ()
+  "Skip whitespace forward, not crossing comment or string boundaries."
+  (let ((saved (point))
+        (string-or-comment (nth 8 (syntax-ppss))))
+    (skip-chars-forward (apply #'string electric-pair-skip-whitespace-chars))
+    (unless (eq string-or-comment (nth 8 (syntax-ppss)))
+      (goto-char saved))))
+
+(defvar electric-pair-text-syntax-table prog-mode-syntax-table
+  "Syntax table used when pairing inside comments and strings.
+
+`electric-pair-mode' considers this syntax table only when point in inside
+quotes or comments. If lookup fails here, `electric-pair-text-pairs' will
+be considered.")
+
+(defun electric-pair-backward-delete-char (n &optional killflag untabify)
+  "Delete characters backward, and maybe also two adjacent paired delimiters.
+
+Remaining behaviour is given by `backward-delete-char' or, if UNTABIFY is
+non-nil, `backward-delete-char-untabify'."
+  (interactive "*p\nP")
+  (let* ((prev (char-before))
+         (next (char-after))
+         (syntax-info (electric-pair-syntax-info prev))
+         (syntax (car syntax-info))
+         (pair (cadr syntax-info)))
+    (when (and (if (functionp electric-pair-delete-adjacent-pairs)
+                   (funcall electric-pair-delete-adjacent-pairs)
+                 electric-pair-delete-adjacent-pairs)
+               next
+               (memq syntax '(?\( ?\" ?\$))
+               (eq pair next))
+      (delete-char 1 killflag))
+    (if untabify
+        (backward-delete-char-untabify n killflag)
+        (backward-delete-char n killflag))))
+
+(defun electric-pair-backward-delete-char-untabify (n &optional killflag)
+  "Delete characters backward, and maybe also two adjacent paired delimiters.
+
+Remaining behaviour is given by `backward-delete-char-untabify'."
+  (interactive "*p\nP")
+  (electric-pair-backward-delete-char n killflag t))
+
+(defun electric-pair-conservative-inhibit (char)
   (or
    ;; I find it more often preferable not to pair when the
    ;; same char is next.
@@ -363,14 +496,40 @@ closer."
    ;; I also find it often preferable not to pair next to a word.
    (eq (char-syntax (following-char)) ?w)))
 
-(defun electric-pair-syntax (command-event)
-  (let ((x (assq command-event electric-pair-pairs)))
+(defun electric-pair-syntax-info (command-event)
+  "Calculate a list (SYNTAX PAIR UNCONDITIONAL STRING-OR-COMMENT-START).
+
+SYNTAX is COMMAND-EVENT's syntax character.  PAIR is
+COMMAND-EVENT's pair.  UNCONDITIONAL indicates the variables
+`electric-pair-pairs' or `electric-pair-text-pairs' were used to
+lookup syntax.  STRING-OR-COMMENT-START indicates that point is
+inside a comment of string."
+  (let* ((pre-string-or-comment (nth 8 (save-excursion
+                                         (syntax-ppss (1- (point))))))
+         (post-string-or-comment (nth 8 (syntax-ppss (point))))
+         (string-or-comment (and post-string-or-comment
+                                 pre-string-or-comment))
+         (table (if string-or-comment
+                    electric-pair-text-syntax-table
+                  (syntax-table)))
+         (table-syntax-and-pair (with-syntax-table table
+                                  (list (char-syntax command-event)
+                                        (or (matching-paren command-event)
+                                            command-event))))
+         (fallback (if string-or-comment
+                       (append electric-pair-text-pairs
+                               electric-pair-pairs)
+                     electric-pair-pairs))
+         (direct (assq command-event fallback))
+         (reverse (rassq command-event fallback)))
     (cond
-     (x (if (eq (car x) (cdr x)) ?\" ?\())
-     ((rassq command-event electric-pair-pairs) ?\))
-     ((nth 8 (syntax-ppss))
-      (with-syntax-table text-mode-syntax-table (char-syntax command-event)))
-     (t (char-syntax command-event)))))
+     ((memq (car table-syntax-and-pair)
+            '(?\" ?\( ?\) ?\$))
+      (append table-syntax-and-pair (list nil string-or-comment)))
+     (direct (if (eq (car direct) (cdr direct))
+                 (list ?\" command-event t string-or-comment)
+               (list ?\( (cdr direct) t string-or-comment)))
+     (reverse (list ?\) (car reverse) t string-or-comment)))))
 
 (defun electric-pair--insert (char)
   (let ((last-command-event char)
@@ -378,56 +537,297 @@ closer."
         (electric-pair-mode nil))
     (self-insert-command 1)))
 
+(defun electric-pair--syntax-ppss (&optional pos where)
+  "Like `syntax-ppss', but sometimes fallback to `parse-partial-sexp'.
+
+WHERE is list defaulting to '(string comment) and indicates
+when to fallback to `parse-partial-sexp'."
+  (let* ((pos (or pos (point)))
+         (where (or where '(string comment)))
+         (quick-ppss (syntax-ppss))
+         (quick-ppss-at-pos (syntax-ppss pos)))
+    (if (or (and (nth 3 quick-ppss) (memq 'string where))
+            (and (nth 4 quick-ppss) (memq 'comment where)))
+        (with-syntax-table electric-pair-text-syntax-table
+          (parse-partial-sexp (1+ (nth 8 quick-ppss)) pos))
+      ;; HACK! cc-mode apparently has some `syntax-ppss' bugs
+      (if (memq major-mode '(c-mode c++ mode))
+          (parse-partial-sexp (point-min) pos)
+        quick-ppss-at-pos))))
+
+;; Balancing means controlling pairing and skipping of parentheses so
+;; that, if possible, the buffer ends up at least as balanced as
+;; before, if not more. The algorithm is slightly complex because some
+;; situations like "()))" need pairing to occur at the end but not at
+;; the beginning. Balancing should also happen independently for
+;; different types of parentheses, so that having your {}'s unbalanced
+;; doesn't keep `electric-pair-mode' from balancing your ()'s and your
+;; []'s.
+(defun electric-pair--balance-info (direction string-or-comment)
+  "Examine lists forward or backward according to DIRECTIONS's sign.
+
+STRING-OR-COMMENT is info suitable for running `parse-partial-sexp'.
+
+Return a cons of two descritions (MATCHED-P . PAIR) for the
+innermost and outermost lists that enclose point. The outermost
+list enclosing point is either the first top-level or first
+mismatched list found by uplisting.
+
+If the outermost list is matched, don't rely on its PAIR. If
+point is not enclosed by any lists, return ((T) (T))."
+  (let* (innermost
+         outermost
+         (table (if string-or-comment
+                    electric-pair-text-syntax-table
+                  (syntax-table)))
+         (at-top-level-or-equivalent-fn
+          ;; called when `scan-sexps' ran perfectly, when when it
+          ;; found a parenthesis pointing in the direction of
+          ;; travel. Also when travel started inside a comment and
+          ;; exited it
+          #'(lambda ()
+              (setq outermost (list t))
+              (unless innermost
+                (setq innermost (list t)))))
+         (ended-prematurely-fn
+          ;; called when `scan-sexps' crashed against a parenthesis
+          ;; pointing opposite the direction of travel. After
+          ;; traversing that character, the idea is to travel one sexp
+          ;; in the opposite direction looking for a matching
+          ;; delimiter.
+          #'(lambda ()
+              (let* ((pos (point))
+                     (matched
+                      (save-excursion
+                        (cond ((< direction 0)
+                               (condition-case nil
+                                   (eq (char-after pos)
+                                       (with-syntax-table table
+                                         (matching-paren
+                                          (char-before
+                                           (scan-sexps (point) 1)))))
+                                 (scan-error nil)))
+                              (t
+                               ;; In this case, no need to use
+                               ;; `scan-sexps', we can use some
+                               ;; `electric-pair--syntax-ppss' in this
+                               ;; case (which uses the quicker
+                               ;; `syntax-ppss' in some cases)
+                               (let* ((ppss (electric-pair--syntax-ppss
+                                             (1- (point))))
+                                      (start (car (last (nth 9 ppss))))
+                                      (opener (char-after start)))
+                                 (and start
+                                      (eq (char-before pos)
+                                          (or (with-syntax-table table
+                                                (matching-paren opener))
+                                              opener))))))))
+                     (actual-pair (if (> direction 0)
+                                      (char-before (point))
+                                    (char-after (point)))))
+                (unless innermost
+                  (setq innermost (cons matched actual-pair)))
+                (unless matched
+                  (setq outermost (cons matched actual-pair)))))))
+    (save-excursion
+      (while (not outermost)
+        (condition-case err
+            (with-syntax-table table
+              (scan-sexps (point) (if (> direction 0)
+                                      (point-max)
+                                    (- (point-max))))
+              (funcall at-top-level-or-equivalent-fn))
+          (scan-error
+           (cond ((or
+                   ;; some error happened and it is not of the "ended
+                   ;; prematurely" kind"...
+                   (not (string-match "ends prematurely" (nth 1 err)))
+                   ;; ... or we were in a comment and just came out of
+                   ;; it.
+                   (and string-or-comment
+                        (not (nth 8 (syntax-ppss)))))
+                  (funcall at-top-level-or-equivalent-fn))
+                 (t
+                  ;; exit the sexp
+                  (goto-char (nth 3 err))
+                  (funcall ended-prematurely-fn)))))))
+    (cons innermost outermost)))
+
+(defun electric-pair--looking-at-unterminated-string-p (char)
+  "Say if following string starts with CHAR and is unterminated."
+  ;; FIXME: ugly/naive
+  (save-excursion
+    (skip-chars-forward (format "^%c" char))
+    (while (not (zerop (% (save-excursion (skip-syntax-backward "\\")) 2)))
+      (unless (eobp)
+        (forward-char 1)
+        (skip-chars-forward (format "^%c" char))))
+    (and (not (eobp))
+         (condition-case err
+             (progn (forward-sexp) nil)
+           (scan-error t)))))
+
+(defun electric-pair--inside-string-p (char)
+  "Say if point is inside a string started by CHAR.
+
+A comments text is parsed with `electric-pair-text-syntax-table'.
+Also consider strings within comments, but not strings within
+strings."
+  ;; FIXME: could also consider strings within strings by examining
+  ;; delimiters.
+  (let* ((ppss (electric-pair--syntax-ppss (point) '(comment))))
+    (memq (nth 3 ppss) (list t char))))
+
+(defun electric-pair-inhibit-if-helps-balance (char)
+  "Return non-nil if auto-pairing of CHAR would hurt parentheses' balance.
+
+Works by first removing the character from the buffer, then doing
+some list calculations, finally restoring the situation as if nothing
+happened."
+  (pcase (electric-pair-syntax-info char)
+    (`(,syntax ,pair ,_ ,s-or-c)
+     (unwind-protect
+         (progn
+           (delete-char -1)
+           (cond ((eq ?\( syntax)
+                  (let* ((pair-data
+                          (electric-pair--balance-info 1 s-or-c))
+                         (innermost (car pair-data))
+                         (outermost (cdr pair-data)))
+                    (cond ((car outermost)
+                           nil)
+                          (t
+                           (eq (cdr outermost) pair)))))
+                 ((eq syntax ?\")
+                  (electric-pair--looking-at-unterminated-string-p char))))
+       (insert-char char)))))
+
+(defun electric-pair-skip-if-helps-balance (char)
+  "Return non-nil if skipping CHAR would benefit parentheses' balance.
+
+Works by first removing the character from the buffer, then doing
+some list calculations, finally restoring the situation as if nothing
+happened."
+  (pcase (electric-pair-syntax-info char)
+    (`(,syntax ,pair ,_ ,s-or-c)
+     (unwind-protect
+         (progn
+           (delete-char -1)
+           (cond ((eq syntax ?\))
+                  (let* ((pair-data
+                          (electric-pair--balance-info
+                           -1 s-or-c))
+                         (innermost (car pair-data))
+                         (outermost (cdr pair-data)))
+                    (and
+                     (cond ((car outermost)
+                            (car innermost))
+                           ((car innermost)
+                            (not (eq (cdr outermost) pair)))))))
+                 ((eq syntax ?\")
+                  (electric-pair--inside-string-p char))))
+       (insert-char char)))))
+
+(defun electric-pair-default-skip-self (char)
+  (if electric-pair-preserve-balance
+      (electric-pair-skip-if-helps-balance char)
+    t))
+
+(defun electric-pair-default-inhibit (char)
+  (if electric-pair-preserve-balance
+      (electric-pair-inhibit-if-helps-balance char)
+    (electric-pair-conservative-inhibit char)))
+
 (defun electric-pair-post-self-insert-function ()
   (let* ((pos (and electric-pair-mode (electric--after-char-pos)))
-         (syntax (and pos (electric-pair-syntax last-command-event)))
-         (closer (if (eq syntax ?\()
-                     (cdr (or (assq last-command-event electric-pair-pairs)
-                              (aref (syntax-table) last-command-event)))
-                   last-command-event)))
-    (cond
-     ((null pos) nil)
-     ;; Wrap a pair around the active region.
-     ((and (memq syntax '(?\( ?\" ?\$)) (use-region-p))
-      ;; FIXME: To do this right, we'd need a post-self-insert-function
-      ;; so we could add-function around it and insert the closer after
-      ;; all the rest of the hook has run.
-      (if (>= (mark) (point))
-          (goto-char (mark))
-        ;; We already inserted the open-paren but at the end of the
-        ;; region, so we have to remove it and start over.
-        (delete-region (1- pos) (point))
-        (save-excursion
-          (goto-char (mark))
-          (electric-pair--insert last-command-event)))
-      ;; Since we're right after the closer now, we could tell the rest of
-      ;; post-self-insert-hook that we inserted `closer', but then we'd get
-      ;; blink-paren to kick in, which is annoying.
-      ;;(setq last-command-event closer)
-      (insert closer))
-     ;; Backslash-escaped: no pairing, no skipping.
-     ((save-excursion
-        (goto-char (1- pos))
-        (not (zerop (% (skip-syntax-backward "\\") 2))))
-      nil)
-     ;; Skip self.
-     ((and (memq syntax '(?\) ?\" ?\$))
-           electric-pair-skip-self
-           (eq (char-after pos) last-command-event))
-      ;; This is too late: rather than insert&delete we'd want to only skip (or
-      ;; insert in overwrite mode).  The difference is in what goes in the
-      ;; undo-log and in the intermediate state which might be visible to other
-      ;; post-self-insert-hook.  We'll just have to live with it for now.
-      (delete-char 1))
-     ;; Insert matching pair.
-     ((not (or (not (memq syntax `(?\( ?\" ?\$)))
-               overwrite-mode
-               (funcall electric-pair-inhibit-predicate last-command-event)))
-      (save-excursion (electric-pair--insert closer))))))
+         (skip-whitespace-info))
+    (pcase (electric-pair-syntax-info last-command-event)
+      (`(,syntax ,pair ,unconditional ,_)
+       (cond
+        ((null pos) nil)
+        ;; Wrap a pair around the active region.
+        ;;
+        ((and (memq syntax '(?\( ?\) ?\" ?\$)) (use-region-p))
+         ;; FIXME: To do this right, we'd need a post-self-insert-function
+         ;; so we could add-function around it and insert the closer after
+         ;; all the rest of the hook has run.
+         (if (or (eq syntax ?\")
+                 (and (eq syntax ?\))
+                      (>= (point) (mark)))
+                 (and (not (eq syntax ?\)))
+                      (>= (mark) (point))))
+             (save-excursion
+               (goto-char (mark))
+               (electric-pair--insert pair))
+           (delete-region pos (1- pos))
+           (electric-pair--insert pair)
+           (goto-char (mark))
+           (electric-pair--insert last-command-event)))
+        ;; Backslash-escaped: no pairing, no skipping.
+        ((save-excursion
+           (goto-char (1- pos))
+           (not (zerop (% (skip-syntax-backward "\\") 2))))
+         nil)
+        ;; Skip self.
+        ((and (memq syntax '(?\) ?\" ?\$))
+              (and (or unconditional
+                       (if (functionp electric-pair-skip-self)
+                           (funcall electric-pair-skip-self last-command-event)
+                         electric-pair-skip-self))
+                   (save-excursion
+                     (when (setq skip-whitespace-info
+                                 (if (functionp electric-pair-skip-whitespace)
+                                     (funcall electric-pair-skip-whitespace)
+                                   electric-pair-skip-whitespace))
+                       (electric-pair--skip-whitespace))
+                     (eq (char-after) last-command-event))))
+         ;; This is too late: rather than insert&delete we'd want to only
+         ;; skip (or insert in overwrite mode).  The difference is in what
+         ;; goes in the undo-log and in the intermediate state which might
+         ;; be visible to other post-self-insert-hook.  We'll just have to
+         ;; live with it for now.
+         (when skip-whitespace-info
+           (electric-pair--skip-whitespace))
+         (delete-region (1- pos) (if (eq skip-whitespace-info 'chomp)
+                                     (point)
+                                   pos))
+         (forward-char))
+        ;; Insert matching pair.
+        ((and (memq syntax `(?\( ?\" ?\$))
+              (not overwrite-mode)
+              (or unconditional
+                  (not (funcall electric-pair-inhibit-predicate
+                                last-command-event))))
+         (save-excursion (electric-pair--insert pair)))))
+      (t
+       (when (and (if (functionp electric-pair-open-newline-between-pairs)
+                      (funcall electric-pair-open-newline-between-pairs)
+                    electric-pair-open-newline-between-pairs)
+                  (eq last-command-event ?\n)
+                  (not (eobp))
+                  (eq (save-excursion
+                        (skip-chars-backward "\t\s")
+                        (char-before (1- (point))))
+                      (matching-paren (char-after))))
+         (save-excursion (newline 1 t)))))))
+
+(put 'electric-pair-post-self-insert-function   'priority  20)
 
 (defun electric-pair-will-use-region ()
   (and (use-region-p)
-       (memq (electric-pair-syntax last-command-event) '(?\( ?\" ?\$))))
+       (memq (car (electric-pair-syntax-info last-command-event))
+             '(?\( ?\) ?\" ?\$))))
+
+(defvar electric-pair-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map [remap backward-delete-char-untabify]
+      'electric-pair-backward-delete-char-untabify)
+    (define-key map [remap backward-delete-char]
+      'electric-pair-backward-delete-char)
+    (define-key map [remap delete-backward-char]
+      'electric-pair-backward-delete-char)
+    map)
+  "Keymap used by `electric-pair-mode'.")
 
 ;;;###autoload
 (define-minor-mode electric-pair-mode
@@ -438,29 +838,33 @@ the mode if ARG is omitted or nil.
 
 Electric Pair mode is a global minor mode.  When enabled, typing
 an open parenthesis automatically inserts the corresponding
-closing parenthesis.  \(Likewise for brackets, etc.)
-
-See options `electric-pair-pairs' and `electric-pair-skip-self'."
+closing parenthesis.  \(Likewise for brackets, etc.)."
   :global t :group 'electricity
   (if electric-pair-mode
       (progn
         (add-hook 'post-self-insert-hook
                   #'electric-pair-post-self-insert-function)
+        (electric--sort-post-self-insertion-hook)
         (add-hook 'self-insert-uses-region-functions
                   #'electric-pair-will-use-region))
     (remove-hook 'post-self-insert-hook
                  #'electric-pair-post-self-insert-function)
     (remove-hook 'self-insert-uses-region-functions
-                  #'electric-pair-will-use-region)))
+                 #'electric-pair-will-use-region)))
 
 ;;; Electric newlines after/before/around some chars.
 
-(defvar electric-layout-rules '()
+(defvar electric-layout-rules nil
   "List of rules saying where to automatically insert newlines.
-Each rule has the form (CHAR . WHERE) where CHAR is the char
-that was just inserted and WHERE specifies where to insert newlines
-and can be: nil, `before', `after', `around', or a function of no
-arguments that returns one of those symbols.")
+
+Each rule has the form (CHAR . WHERE) where CHAR is the char that
+was just inserted and WHERE specifies where to insert newlines
+and can be: nil, `before', `after', `around', `after-stay', or a
+function of no arguments that returns one of those symbols.
+
+The symbols specify where in relation to CHAR the newline
+character(s) should be inserted. `after-stay' means insert a
+newline after CHAR but stay in the same place.")
 
 (defun electric-layout-post-self-insert-function ()
   (let* ((rule (cdr (assq last-command-event electric-layout-rules)))
@@ -469,23 +873,32 @@ arguments that returns one of those symbols.")
                (setq pos (electric--after-char-pos))
                ;; Not in a string or comment.
                (not (nth 8 (save-excursion (syntax-ppss pos)))))
-      (let ((end (copy-marker (point) t)))
+      (let ((end (copy-marker (point)))
+            (sym (if (functionp rule) (funcall rule) rule)))
+        (set-marker-insertion-type end (not (eq sym 'after-stay)))
         (goto-char pos)
-        (pcase (if (functionp rule) (funcall rule) rule)
+        (pcase sym
           ;; FIXME: we used `newline' down here which called
           ;; self-insert-command and ran post-self-insert-hook recursively.
           ;; It happened to make electric-indent-mode work automatically with
           ;; electric-layout-mode (at the cost of re-indenting lines
           ;; multiple times), but I'm not sure it's what we want.
+          ;;
+          ;; FIXME: check eolp before inserting \n?
           (`before (goto-char (1- pos)) (skip-chars-backward " \t")
-                  (unless (bolp) (insert "\n")))
-          (`after  (insert "\n"))      ; FIXME: check eolp before inserting \n?
+                   (unless (bolp) (insert "\n")))
+          (`after  (insert "\n"))
+          (`after-stay (save-excursion
+                         (let ((electric-layout-rules nil))
+                           (newline 1 t))))
           (`around (save-excursion
-                    (goto-char (1- pos)) (skip-chars-backward " \t")
-                    (unless (bolp) (insert "\n")))
-                  (insert "\n")))      ; FIXME: check eolp before inserting \n?
+                     (goto-char (1- pos)) (skip-chars-backward " \t")
+                     (unless (bolp) (insert "\n")))
+                   (insert "\n")))      ; FIXME: check eolp before inserting \n?
         (goto-char end)))))
 
+(put 'electric-layout-post-self-insert-function 'priority  40)
+
 ;;;###autoload
 (define-minor-mode electric-layout-mode
   "Automatically insert newlines around some chars.
@@ -494,11 +907,13 @@ positive, and disable it otherwise.  If called from Lisp, enable
 the mode if ARG is omitted or nil.
 The variable `electric-layout-rules' says when and how to insert newlines."
   :global t :group 'electricity
-  (if electric-layout-mode
-      (add-hook 'post-self-insert-hook
-                #'electric-layout-post-self-insert-function)
-    (remove-hook 'post-self-insert-hook
-                 #'electric-layout-post-self-insert-function)))
+  (cond (electric-layout-mode
+         (add-hook 'post-self-insert-hook
+                   #'electric-layout-post-self-insert-function)
+         (electric--sort-post-self-insertion-hook))
+        (t
+         (remove-hook 'post-self-insert-hook
+                      #'electric-layout-post-self-insert-function))))
 
 (provide 'electric)
 
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index b7bd33f628f..f1eae18c507 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -472,7 +472,13 @@ font-lock keywords will not be case sensitive."
           (font-lock-mark-block-function . mark-defun)
           (font-lock-syntactic-face-function
            . lisp-font-lock-syntactic-face-function)))
-  (setq-local prettify-symbols-alist lisp--prettify-symbols-alist))
+  (setq-local prettify-symbols-alist lisp--prettify-symbols-alist)
+  ;; electric
+  (when elisp
+    (setq-local electric-pair-text-pairs
+                (cons '(?\` . ?\') electric-pair-text-pairs)))
+  (setq-local electric-pair-skip-whitespace 'chomp)
+  (setq-local electric-pair-open-newline-between-pairs nil))
 
 (defun lisp-outline-level ()
   "Lisp mode `outline-level' function."
diff --git a/lisp/simple.el b/lisp/simple.el
index a6543516a9c..624d87fd655 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -610,7 +610,7 @@ In some text modes, where TAB inserts a tab, this command indents to the
 column specified by the function `current-left-margin'."
   (interactive "*")
   (delete-horizontal-space t)
-  (newline)
+  (newline 1 t)
   (indent-according-to-mode))
 
 (defun reindent-then-newline-and-indent ()
@@ -6448,10 +6448,14 @@ More precisely, a char with closeparen syntax is self-inserted.")
                                  (point))))))
     (funcall blink-paren-function)))
 
+(put 'blink-paren-post-self-insert-function 'priority 100)
+
 (add-hook 'post-self-insert-hook #'blink-paren-post-self-insert-function
           ;; Most likely, this hook is nil, so this arg doesn't matter,
           ;; but I use it as a reminder that this function usually
-          ;; likes to be run after others since it does `sit-for'.
+          ;; likes to be run after others since it does
+          ;; `sit-for'. That's also the reason it get a `priority' prop
+          ;; of 100.
           'append)
 
 ;; This executes C-g typed while Emacs is waiting for a command.