From e4ef7a2e2a480b9e1d6a8a869ffa8a7459abe9bd Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jo=C3=A3o=20T=C3=A1vora?= <joaotavora@gmail.com>
Date: Sat, 22 Dec 2018 21:05:23 +0000
Subject: [PATCH] Handle entries of multiple symbols in electric-layout-rules

Instead of allowing multiple rules in electric-layout-rules, allow
rules to specify multiple symbols.  This should be entirely
backward-compatible to existing customizations of that variable.

* lisp/electric.el (electric-layout-rules):  a single entry can
specify multiple symbols.
(electric-layout-post-self-insert-function-1):  rework.

* test/lisp/electric-tests.el: Update tests to work with new semantics
  of electric-layout-rules.
---
 lisp/electric.el            | 49 ++++++++++++++++++++-----------------
 test/lisp/electric-tests.el |  7 ++----
 2 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/lisp/electric.el b/lisp/electric.el
index 6ea2eaeae79..96468077263 100644
--- a/lisp/electric.el
+++ b/lisp/electric.el
@@ -365,15 +365,21 @@ use `electric-indent-local-mode'."
 
 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.
+and can be:
 
-The symbols specify where in relation to CHAR the newline
-character(s) should be inserted. `after-stay' means insert a
+* one of the symbols `before', `after', `around' and `after-stay';
+
+* a list of the preceding symbols, processed in order of
+  appearance to insert multiple newlines;
+
+* a function of no arguments that returns one of the previous
+  values.
+
+Each symbol specifies 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.
 
-If multiple rules match, they are all executed in order of
-appearance.")
+If multiple rules match, only first one is executed.")
 
 (defun electric-layout-post-self-insert-function ()
   (when electric-layout-mode
@@ -381,25 +387,24 @@ appearance.")
 
 ;; for edebug's sake, a separate function
 (defun electric-layout-post-self-insert-function-1 ()
-  (let (pos end)
-    (when (and (setq pos (electric--after-char-pos))
+  (let (pos
+        (rule (cdr (assq last-command-event electric-layout-rules))))
+    (when (and rule
+               (setq pos (electric--after-char-pos))
                ;; Not in a string or comment.
                (not (nth 8 (save-excursion (syntax-ppss pos)))))
       (goto-char pos)
-      (setq end (point-marker))
-      (dolist (rule electric-layout-rules)
-        (when (eq last-command-event (car rule))
-          (let* ((rule (cdr rule))
-                 (sym (if (functionp rule) (funcall rule) rule))
-                 (nl-after
+      (when (functionp rule) (setq rule (funcall rule)))
+      (dolist (sym (if (symbolp rule) (list rule) rule))
+        (let* ((nl-after
                   (lambda ()
-                    ;; FIXME: we use `newline'which calls
-                    ;; 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: we use `newline', which calls
+                    ;; `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: when `newline'ing, we exceptionally
                     ;; prevent a specific behaviour of
@@ -422,7 +427,7 @@ appearance.")
               ('before (funcall nl-before))
               ('after  (funcall nl-after))
               ('after-stay (save-excursion (funcall nl-after)))
-              ('around (funcall nl-before) (funcall nl-after)))))))))
+              ('around (funcall nl-before) (funcall nl-after))))))))
 
 (put 'electric-layout-post-self-insert-function 'priority  40)
 
diff --git a/test/lisp/electric-tests.el b/test/lisp/electric-tests.el
index 971c3e95677..b798a3fac7b 100644
--- a/test/lisp/electric-tests.el
+++ b/test/lisp/electric-tests.el
@@ -823,8 +823,7 @@ baz\"\""
       (electric-pair-local-mode 1)
       (electric-indent-local-mode 1)
       (setq-local electric-layout-rules
-              '((?\{ . after)
-                (?\{ . after-stay)))
+              '((?\{ . (after after-stay))))
       (insert "int main () ")
       (let ((last-command-event ?\{))
         (call-interactively (key-binding `[,last-command-event])))
@@ -838,9 +837,7 @@ baz\"\""
       (electric-pair-local-mode 1)
       (electric-indent-local-mode 1)
       (setq-local electric-layout-rules
-              '((?\{ . before)
-                (?\{ . after)
-                (?\{ . after-stay)))
+              '((?\{ . (before after after-stay))))
       (insert "int main () ")
       (let ((last-command-event ?\{))
         (call-interactively (key-binding `[,last-command-event])))
-- 
2.39.2