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emacs/lisp/fileloop.el
Noam Postavsky a477a7b86b Don't lose point during fileloop replace (Bug#38867)
Suggested by Eric Michael Timmons <etimmons@mit.edu>.
* lisp/fileloop.el (fileloop-initialize-replace): Save the
match-beginning position in a variable instead of the buffer's point.
The point may be changed by the time perform-replace is called, e.g.,
due to switch-to-buffer-preserve-window-point.
2020-03-31 18:17:53 -04:00

222 lines
8.2 KiB
EmacsLisp

;;; fileloop.el --- Operations on multiple files -*- lexical-binding: t; -*-
;; Copyright (C) 2018-2020 Free Software Foundation, Inc.
;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; Support functions for operations like search or query&replace applied to
;; several files. This code was largely inspired&extracted from an earlier
;; version of etags.el.
;; TODO:
;; - Maybe it would make sense to replace the fileloop--* vars with a single
;; global var holding a struct, and then stash those structs into a history
;; of past operations, so you can perform a fileloop-search while in the
;; middle of a fileloop-replace and later go back to that
;; fileloop-replace.
;; - Make multi-isearch work on top of this library (might require changes
;; to this library, of course).
;;; Code:
(require 'generator)
(defgroup fileloop nil
"Operations on multiple files."
:group 'tools)
(defcustom fileloop-revert-buffers 'silent
"Whether to revert files during fileloop operation.
`silent' means to only do it if `revert-without-query' is applicable;
t means to offer to do it for all applicable files;
nil means never to do it"
:type '(choice (const silent) (const t) (const nil)))
;; FIXME: This already exists in GNU ELPA's iterator.el. Maybe it should move
;; to generator.el?
(iter-defun fileloop--list-to-iterator (list)
(while list (iter-yield (pop list))))
(defvar fileloop--iterator iter-empty)
(defvar fileloop--scan-function
(lambda () (user-error "No operation in progress")))
(defvar fileloop--operate-function #'ignore)
(defvar fileloop--freshly-initialized nil)
;;;###autoload
(defun fileloop-initialize (files scan-function operate-function)
"Initialize a new round of operation on several files.
FILES can be either a list of file names, or an iterator (used with `iter-next')
which returns a file name at each step.
SCAN-FUNCTION is a function called with no argument inside a buffer
and it should return non-nil if that buffer has something on which to operate.
OPERATE-FUNCTION is a function called with no argument; it is expected
to perform the operation on the current file buffer and when done
should return non-nil to mean that we should immediately continue
operating on the next file and nil otherwise."
(setq fileloop--iterator
(if (and (listp files) (not (functionp files)))
(fileloop--list-to-iterator files)
files))
(setq fileloop--scan-function scan-function)
(setq fileloop--operate-function operate-function)
(setq fileloop--freshly-initialized t))
(defun fileloop-next-file (&optional novisit)
;; FIXME: Should we provide an interactive command, like tags-next-file?
(let ((next (condition-case nil
(iter-next fileloop--iterator)
(iter-end-of-sequence nil))))
(unless next
(and novisit
(get-buffer " *next-file*")
(kill-buffer " *next-file*"))
(user-error "All files processed"))
(let* ((buffer (get-file-buffer next))
(new (not buffer)))
;; Optionally offer to revert buffers
;; if the files have changed on disk.
(and buffer fileloop-revert-buffers
(not (verify-visited-file-modtime buffer))
(if (eq fileloop-revert-buffers 'silent)
(and (not (buffer-modified-p buffer))
(let ((revertible nil))
(dolist (re revert-without-query)
(when (string-match-p re next)
(setq revertible t)))
revertible))
(y-or-n-p
(format
(if (buffer-modified-p buffer)
"File %s changed on disk. Discard your edits? "
"File %s changed on disk. Reread from disk? ")
next)))
(with-current-buffer buffer
(revert-buffer t t)))
(if (not (and new novisit))
(set-buffer (find-file-noselect next))
;; Like find-file, but avoids random warning messages.
(set-buffer (get-buffer-create " *next-file*"))
(kill-all-local-variables)
(erase-buffer)
(setq new next)
(insert-file-contents new nil))
new)))
(defun fileloop-continue ()
"Continue last multi-file operation."
(interactive)
(let (new
;; Non-nil means we have finished one file
;; and should not scan it again.
file-finished
original-point
(messaged nil))
(while
(progn
;; Scan files quickly for the first or next interesting one.
;; This starts at point in the current buffer.
(while (or fileloop--freshly-initialized file-finished
(save-restriction
(widen)
(not (funcall fileloop--scan-function))))
;; If nothing was found in the previous file, and
;; that file isn't in a temp buffer, restore point to
;; where it was.
(when original-point
(goto-char original-point))
(setq file-finished nil)
(setq new (fileloop-next-file t))
;; If NEW is non-nil, we got a temp buffer,
;; and NEW is the file name.
(when (or messaged
(and (not fileloop--freshly-initialized)
(> baud-rate search-slow-speed)
(setq messaged t)))
(message "Scanning file %s..." (or new buffer-file-name)))
(setq fileloop--freshly-initialized nil)
(setq original-point (if new nil (point)))
(goto-char (point-min)))
;; If we visited it in a temp buffer, visit it now for real.
(if new
(let ((pos (point)))
(erase-buffer)
(set-buffer (find-file-noselect new))
(setq new nil) ;No longer in a temp buffer.
(widen)
(goto-char pos))
(push-mark original-point t))
(switch-to-buffer (current-buffer))
;; Now operate on the file.
;; If value is non-nil, continue to scan the next file.
(save-restriction
(widen)
(funcall fileloop--operate-function)))
(setq file-finished t))))
;;;###autoload
(defun fileloop-initialize-search (regexp files case-fold)
(let ((last-buffer (current-buffer)))
(fileloop-initialize
files
(lambda ()
(let ((case-fold-search
(if (memq case-fold '(t nil)) case-fold case-fold-search)))
(re-search-forward regexp nil t)))
(lambda ()
(unless (eq last-buffer (current-buffer))
(setq last-buffer (current-buffer))
(message "Scanning file %s...found" buffer-file-name))
nil))))
;;;###autoload
(defun fileloop-initialize-replace (from to files case-fold &optional delimited)
"Initialize a new round of query&replace on several files.
FROM is a regexp and TO is the replacement to use.
FILES describes the file, as in `fileloop-initialize'.
CASE-FOLD can be t, nil, or `default', the latter one meaning to obey
the default setting of `case-fold-search'.
DELIMITED if non-nil means replace only word-delimited matches."
;; FIXME: Not sure how the delimited-flag interacts with the regexp-flag in
;; `perform-replace', so I just try to mimic the old code.
(let ((mstart (make-hash-table :test 'eq)))
(fileloop-initialize
files
(lambda ()
(let ((case-fold-search
(if (memql case-fold '(nil t)) case-fold case-fold-search)))
(when (re-search-forward from nil t)
;; When we find a match, save its beginning for
;; `perform-replace' (we used to just set point, but this
;; is unreliable in the face of
;; `switch-to-buffer-preserve-window-point').
(puthash (current-buffer) (match-beginning 0) mstart))))
(lambda ()
(perform-replace from to t t delimited nil multi-query-replace-map
(gethash (current-buffer) mstart (point-min))
(point-max))))))
(provide 'fileloop)
;;; fileloop.el ends here