From 0b038ef868a8c558e66d420b9380b792b409e388 Mon Sep 17 00:00:00 2001 From: Jim Porter Date: Sun, 12 Sep 2021 10:44:55 -0700 Subject: [PATCH] Improve behavior of 'electric-pair-mode' in 'cc-mode' This ensures that quotes are paired correctly within comments, allows for insertion of quote pairs immediately before another quote, and allows inserting quote pairs within a string (thus splitting the string in two). * lisp/progmodes/cc-mode.el (c-electric-pair-inhibit-predicate): Inhibit insertion of paired quote in fewer cases. * test/lisp/electric-tests.el (define-electric-pair-test): Add 'c-mode' to list of modes to test by default. --- lisp/progmodes/cc-mode.el | 21 ++++++++++++++------- test/lisp/electric-tests.el | 5 ++++- 2 files changed, 18 insertions(+), 8 deletions(-) diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el index 057d292246..012488a7b1 100644 --- a/lisp/progmodes/cc-mode.el +++ b/lisp/progmodes/cc-mode.el @@ -2550,18 +2550,25 @@ c-electric-pair-inhibit-predicate At the time of call, point is just after the newly inserted CHAR. -When CHAR is \", t will be returned unless the \" is marked with -a string fence syntax-table text property. For other characters, -the default value of `electric-pair-inhibit-predicate' is called -and its value returned. +When CHAR is \" and not within a comment, t will be returned if +the quotes on the current line are already balanced (i.e. if the +last \" is not marked with a string fence syntax-table text +property). For other cases, the default value of +`electric-pair-inhibit-predicate' is called and its value +returned. This function is the appropriate value of `electric-pair-inhibit-predicate' for CC Mode modes, which mark invalid strings with such a syntax table text property on the opening \" and the next unescaped end of line." - (if (eq char ?\") - (not (equal (get-text-property (1- (point)) 'c-fl-syn-tab) '(15))) - (funcall (default-value 'electric-pair-inhibit-predicate) char))) + (or (and (eq char ?\") + (not (nth 4 (save-excursion (syntax-ppss (1- (point)))))) + (let ((last-quote (save-match-data + (save-excursion + (search-forward "\n" nil 'move) + (search-backward "\"" nil))))) + (not (equal (get-text-property last-quote 'c-fl-syn-tab) '(15))))) + (funcall (default-value 'electric-pair-inhibit-predicate) char))) ;; Support for C diff --git a/test/lisp/electric-tests.el b/test/lisp/electric-tests.el index 666de89c53..35516a9f0b 100644 --- a/test/lisp/electric-tests.el +++ b/test/lisp/electric-tests.el @@ -32,6 +32,9 @@ (require 'elec-pair) (require 'cl-lib) +;; When running tests in c-mode, use single-line comments (//). +(add-hook 'c-mode-hook (lambda () (c-toggle-comment-style -1))) + (defun call-with-saved-electric-modes (fn) (let ((saved-electric (if electric-pair-mode 1 -1)) (saved-layout (if electric-layout-mode 1 -1)) @@ -173,7 +176,7 @@ define-electric-pair-test expected-string expected-point bindings - (modes '(quote (ruby-mode js-mode))) + (modes '(quote (ruby-mode js-mode c-mode))) (test-in-comments t) (test-in-strings t) (test-in-code t) -- 2.25.1