Commit 7100ff98 authored by Stefan Monnier's avatar Stefan Monnier
Browse files

* lisp/electric.el (electric-layout-mode): New minor mode.

(electric--after-char-pos): New function.
(electric-indent-post-self-insert-function): Use it.
(electric-layout-rules): New var.
(electric-layout-post-self-insert-function): New function.
(electric-indent-mode): Make them interact better.
parent 77cd1a62
......@@ -543,7 +543,8 @@ system or session bus.
* New Modes and Packages in Emacs 24.1
** New global minor modes electric-pair-mode and electric-indent-mode.
** New global minor modes electric-pair-mode, electric-indent-mode,
and electric-layout-mode.
** pcase.el provides the ML-style pattern matching macro `pcase'.
......
2010-11-16 Stefan Monnier <monnier@iro.umontreal.ca>
* electric.el (electric-layout-mode): New minor mode.
(electric--after-char-pos): New function.
(electric-indent-post-self-insert-function): Use it.
(electric-layout-rules): New var.
(electric-layout-post-self-insert-function): New function.
(electric-indent-mode): Make them interact better.
2010-11-15 Stefan Monnier <monnier@iro.umontreal.ca>
 
* emacs-lisp/checkdoc.el (checkdoc-syntax-table): Fix last change.
......
......@@ -176,6 +176,20 @@
"Electric behavior for self inserting keys."
:group 'editing)
(defun electric--after-char-pos ()
"Return the position after the char we just inserted.
Returns nil when we can't find this char."
(let ((pos (point)))
(when (or (eq (char-before) last-command-event) ;; Sanity check.
(save-excursion
(or (progn (skip-chars-backward " \t")
(setq pos (point))
(eq (char-before) last-command-event))
(progn (skip-chars-backward " \n\t")
(setq pos (point))
(eq (char-before) last-command-event)))))
pos)))
;; Electric indentation.
;; Autoloading variables is generally undesirable, but major modes
......@@ -193,35 +207,35 @@
;; electric-pair-mode wrapping a region with a pair of parens.
;; There might be a way to get it working by analyzing buffer-undo-list, but
;; it looks challenging.
(when (and (memq last-command-event electric-indent-chars)
;; Don't reindent while inserting spaces at beginning of line.
(or (not (memq last-command-event '(?\s ?\t)))
(save-excursion (skip-chars-backward " \t") (not (bolp))))
;; Not in a string or comment.
(not (nth 8 (syntax-ppss))))
;; For newline, we want to reindent both lines and basically behave like
;; reindent-then-newline-and-indent (whose code we hence copied).
(when (and (eq last-command-event ?\n)
;; Don't reindent the previous line if the indentation function
;; is not a real one.
(not (memq indent-line-function
'(indent-relative indent-relative-maybe)))
;; Sanity check.
(eq (char-before) last-command-event))
(let ((pos (copy-marker (1- (point)) t)))
(save-excursion
(goto-char pos)
(indent-according-to-mode)
;; We are at EOL before the call to indent-according-to-mode, and
;; after it we usually are as well, but not always. We tried to
;; address it with `save-excursion' but that uses a normal marker
;; whereas we need `move after insertion', so we do the
;; save/restore by hand.
(goto-char pos)
;; Remove the trailing whitespace after indentation because
;; indentation may (re)introduce the whitespace.
(delete-horizontal-space t))))
(indent-according-to-mode)))
(let (pos)
(when (and (memq last-command-event electric-indent-chars)
;; Don't reindent while inserting spaces at beginning of line.
(or (not (memq last-command-event '(?\s ?\t)))
(save-excursion (skip-chars-backward " \t") (not (bolp))))
(setq pos (electric--after-char-pos))
;; Not in a string or comment.
(not (nth 8 (save-excursion (syntax-ppss pos)))))
;; For newline, we want to reindent both lines and basically behave like
;; reindent-then-newline-and-indent (whose code we hence copied).
(when (and (< (1- pos) (line-beginning-position))
;; Don't reindent the previous line if the indentation
;; function is not a real one.
(not (memq indent-line-function
'(indent-relative indent-relative-maybe))))
(let ((before (copy-marker (1- pos) t)))
(save-excursion
(goto-char before)
(indent-according-to-mode)
;; We are at EOL before the call to indent-according-to-mode, and
;; after it we usually are as well, but not always. We tried to
;; address it with `save-excursion' but that uses a normal marker
;; whereas we need `move after insertion', so we do the
;; save/restore by hand.
(goto-char before)
;; Remove the trailing whitespace after indentation because
;; indentation may (re)introduce the whitespace.
(delete-horizontal-space t))))
(indent-according-to-mode))))
;;;###autoload
(define-minor-mode electric-indent-mode
......@@ -233,7 +247,17 @@
(add-hook 'post-self-insert-hook
#'electric-indent-post-self-insert-function)
(remove-hook 'post-self-insert-hook
#'electric-indent-post-self-insert-function)))
#'electric-indent-post-self-insert-function))
;; FIXME: electric-indent-mode and electric-layout-mode interact
;; in non-trivial ways. It turns out that electric-indent-mode works
;; better if it is run *after* electric-layout-mode's hook.
(when (memq #'electric-layout-post-self-insert-function
(memq #'electric-indent-post-self-insert-function
(default-value 'post-self-insert-hook)))
(remove-hook 'post-self-insert-hook
#'electric-layout-post-self-insert-function)
(add-hook 'post-self-insert-hook
#'electric-layout-post-self-insert-function)))
;; Electric pairing.
......@@ -302,7 +326,48 @@ This can be convenient for people who find it easier to hit ) than C-f."
#'electric-pair-post-self-insert-function)
(remove-hook 'post-self-insert-hook
#'electric-pair-post-self-insert-function)))
;; Automatically add newlines after/before/around some chars.
(defvar electric-layout-rules '()
"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 that returns
one of those symbols.")
(defun electric-layout-post-self-insert-function ()
(let* ((rule (cdr (assq last-command-event electric-layout-rules)))
pos)
(when (and rule
(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)))
(goto-char pos)
(case (if (functionp rule) (funcall rule) rule)
;; 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.
(before (goto-char (1- pos)) (insert "\n"))
(after (insert "\n"))
(around (goto-char (1- pos)) (insert "\n")
(forward-char 1) (insert "\n")))
(goto-char end)))))
;;;###autoload
(define-minor-mode electric-layout-mode
"Automatically insert newlines around some chars."
: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)))
(provide 'electric)
;; arch-tag: dae045eb-dc2d-4fb7-9f27-9cc2ce277be8
......
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