mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-11 09:20:51 +00:00
a1f543b4aa
* lisp/international/mule-util.el (filepos-to-bufferpos--dos): New auxiliary function, extracted from filepos-to-bufferpos. Make sure it terminates. (filepos-to-bufferpos): Use it to fix the latin-1-dos case. Add support for the `exact' quality.
391 lines
14 KiB
EmacsLisp
391 lines
14 KiB
EmacsLisp
;;; mule-util.el --- utility functions for multilingual environment (mule) -*- lexical-binding:t -*-
|
||
|
||
;; Copyright (C) 1997-1998, 2000-2015 Free Software Foundation, Inc.
|
||
;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
|
||
;; 2005, 2006, 2007, 2008, 2009, 2010, 2011
|
||
;; National Institute of Advanced Industrial Science and Technology (AIST)
|
||
;; Registration Number H14PRO021
|
||
;; Copyright (C) 2003
|
||
;; National Institute of Advanced Industrial Science and Technology (AIST)
|
||
;; Registration Number H13PRO009
|
||
|
||
;; Keywords: mule, multilingual
|
||
|
||
;; This file is part of GNU Emacs.
|
||
|
||
;; GNU Emacs 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.
|
||
|
||
;; GNU Emacs 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 GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
|
||
|
||
;;; Commentary:
|
||
|
||
;;; Code:
|
||
|
||
;;; String manipulations while paying attention to multibyte characters.
|
||
|
||
;;;###autoload
|
||
(defsubst string-to-list (string)
|
||
"Return a list of characters in STRING."
|
||
(append string nil))
|
||
|
||
;;;###autoload
|
||
(defsubst string-to-vector (string)
|
||
"Return a vector of characters in STRING."
|
||
(vconcat string))
|
||
|
||
;;;###autoload
|
||
(defun store-substring (string idx obj)
|
||
"Embed OBJ (string or character) at index IDX of STRING."
|
||
(if (integerp obj)
|
||
(aset string idx obj)
|
||
(let ((len1 (length obj))
|
||
(i 0))
|
||
(while (< i len1)
|
||
(aset string (+ idx i) (aref obj i))
|
||
(setq i (1+ i)))))
|
||
string)
|
||
|
||
(defvar truncate-string-ellipsis "..." ;"…"
|
||
"String to use to indicate truncation.")
|
||
|
||
;;;###autoload
|
||
(defun truncate-string-to-width (str end-column
|
||
&optional start-column padding ellipsis)
|
||
"Truncate string STR to end at column END-COLUMN.
|
||
The optional 3rd arg START-COLUMN, if non-nil, specifies the starting
|
||
column; that means to return the characters occupying columns
|
||
START-COLUMN ... END-COLUMN of STR. Both END-COLUMN and START-COLUMN
|
||
are specified in terms of character display width in the current
|
||
buffer; see also `char-width'.
|
||
|
||
The optional 4th arg PADDING, if non-nil, specifies a padding
|
||
character (which should have a display width of 1) to add at the end
|
||
of the result if STR doesn't reach column END-COLUMN, or if END-COLUMN
|
||
comes in the middle of a character in STR. PADDING is also added at
|
||
the beginning of the result if column START-COLUMN appears in the
|
||
middle of a character in STR.
|
||
|
||
If PADDING is nil, no padding is added in these cases, so
|
||
the resulting string may be narrower than END-COLUMN.
|
||
|
||
If ELLIPSIS is non-nil, it should be a string which will replace the
|
||
end of STR (including any padding) if it extends beyond END-COLUMN,
|
||
unless the display width of STR is equal to or less than the display
|
||
width of ELLIPSIS. If it is non-nil and not a string, then ELLIPSIS
|
||
defaults to `truncate-string-ellipsis'."
|
||
(or start-column
|
||
(setq start-column 0))
|
||
(when (and ellipsis (not (stringp ellipsis)))
|
||
(setq ellipsis truncate-string-ellipsis))
|
||
(let ((str-len (length str))
|
||
(str-width (string-width str))
|
||
(ellipsis-width (if ellipsis (string-width ellipsis) 0))
|
||
(idx 0)
|
||
(column 0)
|
||
(head-padding "") (tail-padding "")
|
||
ch last-column last-idx from-idx)
|
||
(condition-case nil
|
||
(while (< column start-column)
|
||
(setq ch (aref str idx)
|
||
column (+ column (char-width ch))
|
||
idx (1+ idx)))
|
||
(args-out-of-range (setq idx str-len)))
|
||
(if (< column start-column)
|
||
(if padding (make-string end-column padding) "")
|
||
(when (and padding (> column start-column))
|
||
(setq head-padding (make-string (- column start-column) padding)))
|
||
(setq from-idx idx)
|
||
(when (>= end-column column)
|
||
(if (and (< end-column str-width)
|
||
(> str-width ellipsis-width))
|
||
(setq end-column (- end-column ellipsis-width))
|
||
(setq ellipsis ""))
|
||
(condition-case nil
|
||
(while (< column end-column)
|
||
(setq last-column column
|
||
last-idx idx
|
||
ch (aref str idx)
|
||
column (+ column (char-width ch))
|
||
idx (1+ idx)))
|
||
(args-out-of-range (setq idx str-len)))
|
||
(when (> column end-column)
|
||
(setq column last-column
|
||
idx last-idx))
|
||
(when (and padding (< column end-column))
|
||
(setq tail-padding (make-string (- end-column column) padding))))
|
||
(concat head-padding (substring str from-idx idx)
|
||
tail-padding ellipsis))))
|
||
|
||
|
||
;;; Nested alist handler.
|
||
;; Nested alist is alist whose elements are also nested alist.
|
||
|
||
;;;###autoload
|
||
(defsubst nested-alist-p (obj)
|
||
"Return t if OBJ is a nested alist.
|
||
|
||
Nested alist is a list of the form (ENTRY . BRANCHES), where ENTRY is
|
||
any Lisp object, and BRANCHES is a list of cons cells of the form
|
||
\(KEY-ELEMENT . NESTED-ALIST).
|
||
|
||
You can use a nested alist to store any Lisp object (ENTRY) for a key
|
||
sequence KEYSEQ, where KEYSEQ is a sequence of KEY-ELEMENT. KEYSEQ
|
||
can be a string, a vector, or a list."
|
||
(and obj (listp obj) (listp (cdr obj))))
|
||
|
||
;;;###autoload
|
||
(defun set-nested-alist (keyseq entry alist &optional len branches)
|
||
"Set ENTRY for KEYSEQ in a nested alist ALIST.
|
||
Optional 4th arg LEN non-nil means the first LEN elements in KEYSEQ
|
||
are considered.
|
||
Optional 5th argument BRANCHES if non-nil is branches for a keyseq
|
||
longer than KEYSEQ.
|
||
See the documentation of `nested-alist-p' for more detail."
|
||
(or (nested-alist-p alist)
|
||
(error "Invalid argument %s" alist))
|
||
(let ((islist (listp keyseq))
|
||
(len (or len (length keyseq)))
|
||
(i 0)
|
||
key-elt slot)
|
||
(while (< i len)
|
||
(if (null (nested-alist-p alist))
|
||
(error "Keyseq %s is too long for this nested alist" keyseq))
|
||
(setq key-elt (if islist (nth i keyseq) (aref keyseq i)))
|
||
(setq slot (assoc key-elt (cdr alist)))
|
||
(unless slot
|
||
(setq slot (cons key-elt (list t)))
|
||
(setcdr alist (cons slot (cdr alist))))
|
||
(setq alist (cdr slot))
|
||
(setq i (1+ i)))
|
||
(setcar alist entry)
|
||
(if branches
|
||
(setcdr (last alist) branches))))
|
||
|
||
;;;###autoload
|
||
(defun lookup-nested-alist (keyseq alist &optional len start nil-for-too-long)
|
||
"Look up key sequence KEYSEQ in nested alist ALIST. Return the definition.
|
||
Optional 3rd argument LEN specifies the length of KEYSEQ.
|
||
Optional 4th argument START specifies index of the starting key.
|
||
The returned value is normally a nested alist of which
|
||
car part is the entry for KEYSEQ.
|
||
If ALIST is not deep enough for KEYSEQ, return number which is
|
||
how many key elements at the front of KEYSEQ it takes
|
||
to reach a leaf in ALIST.
|
||
Optional 5th argument NIL-FOR-TOO-LONG non-nil means return nil
|
||
even if ALIST is not deep enough."
|
||
(or (nested-alist-p alist)
|
||
(error "Invalid argument %s" alist))
|
||
(or len
|
||
(setq len (length keyseq)))
|
||
(let ((i (or start 0)))
|
||
(if (catch 'lookup-nested-alist-tag
|
||
(if (listp keyseq)
|
||
(while (< i len)
|
||
(if (setq alist (cdr (assoc (nth i keyseq) (cdr alist))))
|
||
(setq i (1+ i))
|
||
(throw 'lookup-nested-alist-tag t))))
|
||
(while (< i len)
|
||
(if (setq alist (cdr (assoc (aref keyseq i) (cdr alist))))
|
||
(setq i (1+ i))
|
||
(throw 'lookup-nested-alist-tag t))))
|
||
;; KEYSEQ is too long.
|
||
(if nil-for-too-long nil i)
|
||
alist)))
|
||
|
||
|
||
;; Coding system related functions.
|
||
|
||
;;;###autoload
|
||
(defun coding-system-post-read-conversion (coding-system)
|
||
"Return the value of CODING-SYSTEM's `post-read-conversion' property."
|
||
(coding-system-get coding-system :post-read-conversion))
|
||
|
||
;;;###autoload
|
||
(defun coding-system-pre-write-conversion (coding-system)
|
||
"Return the value of CODING-SYSTEM's `pre-write-conversion' property."
|
||
(coding-system-get coding-system :pre-write-conversion))
|
||
|
||
;;;###autoload
|
||
(defun coding-system-translation-table-for-decode (coding-system)
|
||
"Return the value of CODING-SYSTEM's `decode-translation-table' property."
|
||
(coding-system-get coding-system :decode-translation-table))
|
||
|
||
;;;###autoload
|
||
(defun coding-system-translation-table-for-encode (coding-system)
|
||
"Return the value of CODING-SYSTEM's `encode-translation-table' property."
|
||
(coding-system-get coding-system :encode-translation-table))
|
||
|
||
;;;###autoload
|
||
(defmacro with-coding-priority (coding-systems &rest body)
|
||
"Execute BODY like `progn' with CODING-SYSTEMS at the front of priority list.
|
||
CODING-SYSTEMS is a list of coding systems. See `set-coding-system-priority'.
|
||
This affects the implicit sorting of lists of coding systems returned by
|
||
operations such as `find-coding-systems-region'."
|
||
(let ((current (make-symbol "current")))
|
||
`(let ((,current (coding-system-priority-list)))
|
||
(apply #'set-coding-system-priority ,coding-systems)
|
||
(unwind-protect
|
||
(progn ,@body)
|
||
(apply #'set-coding-system-priority ,current)))))
|
||
;;;###autoload(put 'with-coding-priority 'lisp-indent-function 1)
|
||
(put 'with-coding-priority 'edebug-form-spec t)
|
||
|
||
;;;###autoload
|
||
(defmacro detect-coding-with-priority (from to priority-list)
|
||
"Detect a coding system of the text between FROM and TO with PRIORITY-LIST.
|
||
PRIORITY-LIST is an alist of coding categories vs the corresponding
|
||
coding systems ordered by priority."
|
||
(declare (obsolete with-coding-priority "23.1"))
|
||
`(with-coding-priority (mapcar #'cdr ,priority-list)
|
||
(detect-coding-region ,from ,to)))
|
||
|
||
;;;###autoload
|
||
(defun detect-coding-with-language-environment (from to lang-env)
|
||
"Detect a coding system for the text between FROM and TO with LANG-ENV.
|
||
The detection takes into account the coding system priorities for the
|
||
language environment LANG-ENV."
|
||
(let ((coding-priority (get-language-info lang-env 'coding-priority)))
|
||
(if coding-priority
|
||
(with-coding-priority coding-priority
|
||
(detect-coding-region from to)))))
|
||
|
||
(declare-function internal-char-font "fontset.c" (position &optional ch))
|
||
|
||
;;;###autoload
|
||
(defun char-displayable-p (char)
|
||
"Return non-nil if we should be able to display CHAR.
|
||
On a multi-font display, the test is only whether there is an
|
||
appropriate font from the selected frame's fontset to display
|
||
CHAR's charset in general. Since fonts may be specified on a
|
||
per-character basis, this may not be accurate."
|
||
(cond ((< char 128)
|
||
;; ASCII characters are always displayable.
|
||
t)
|
||
((not enable-multibyte-characters)
|
||
;; Maybe there's a font for it, but we can't put it in the buffer.
|
||
nil)
|
||
((display-multi-font-p)
|
||
;; On a window system, a character is displayable if we have
|
||
;; a font for that character in the default face of the
|
||
;; currently selected frame.
|
||
(car (internal-char-font nil char)))
|
||
(t
|
||
;; On a terminal, a character is displayable if the coding
|
||
;; system for the terminal can encode it.
|
||
(let ((coding (terminal-coding-system)))
|
||
(when coding
|
||
(let ((cs-list (coding-system-get coding :charset-list)))
|
||
(cond
|
||
((listp cs-list)
|
||
(catch 'tag
|
||
(mapc #'(lambda (charset)
|
||
(if (encode-char char charset)
|
||
(throw 'tag charset)))
|
||
cs-list)
|
||
nil))
|
||
((eq cs-list 'iso-2022)
|
||
(catch 'tag2
|
||
(mapc #'(lambda (charset)
|
||
(if (and (plist-get (charset-plist charset)
|
||
:iso-final-char)
|
||
(encode-char char charset))
|
||
(throw 'tag2 charset)))
|
||
charset-list)
|
||
nil))
|
||
((eq cs-list 'emacs-mule)
|
||
(catch 'tag3
|
||
(mapc #'(lambda (charset)
|
||
(if (and (plist-get (charset-plist charset)
|
||
:emacs-mule-id)
|
||
(encode-char char charset))
|
||
(throw 'tag3 charset)))
|
||
charset-list)
|
||
nil)))))))))
|
||
|
||
(defun filepos-to-bufferpos--dos (byte f)
|
||
(let ((eol-offset 0)
|
||
;; Make sure we terminate, even if BYTE falls right in the middle
|
||
;; of a CRLF or some other weird corner case.
|
||
(omin 0) (omax most-positive-fixnum)
|
||
pos lines)
|
||
(while
|
||
(progn
|
||
(setq pos (funcall f (- byte eol-offset)))
|
||
;; Adjust POS for DOS EOL format.
|
||
(setq lines (1- (line-number-at-pos pos)))
|
||
(and (not (= lines eol-offset)) (> omax omin)))
|
||
(if (> lines eol-offset)
|
||
(setq omax (min (1- omax) lines)
|
||
eol-offset omax)
|
||
(setq omin (max (1+ omin) lines)
|
||
eol-offset omin)))
|
||
pos))
|
||
|
||
;;;###autoload
|
||
(defun filepos-to-bufferpos (byte &optional quality coding-system)
|
||
"Try to return the buffer position corresponding to a particular file position.
|
||
The file position is given as a (0-based) BYTE count.
|
||
The function presumes the file is encoded with CODING-SYSTEM, which defaults
|
||
to `buffer-file-coding-system'.
|
||
QUALITY can be:
|
||
`approximate', in which case we may cut some corners to avoid
|
||
excessive work.
|
||
`exact', in which case we may end up re-(en/de)coding a large
|
||
part of the file/buffer.
|
||
nil, in which case we may return nil rather than an approximation."
|
||
(unless coding-system (setq coding-system buffer-file-coding-system))
|
||
(let ((eol (coding-system-eol-type coding-system))
|
||
(type (coding-system-type coding-system))
|
||
(pm (save-restriction (widen) (point-min))))
|
||
(pcase type
|
||
(`utf-8
|
||
(when (coding-system-get coding-system :bom)
|
||
(setq byte (max 0 (- byte 3))))
|
||
(if (= eol 1)
|
||
(filepos-to-bufferpos--dos (+ pm byte) #'byte-to-position)
|
||
(byte-to-position (+ pm byte))))
|
||
;; FIXME: What if it's a 2-byte charset? Are there such beasts?
|
||
(`charset
|
||
(if (= eol 1)
|
||
(filepos-to-bufferpos--dos (+ pm byte) #'identity)
|
||
(+ pm byte)))
|
||
(_
|
||
(pcase quality
|
||
(`approximate (byte-to-position (+ pm byte)))
|
||
(`exact
|
||
;; Rather than assume that the file exists and still holds the right
|
||
;; data, we reconstruct it based on the buffer's content.
|
||
(let ((buf (current-buffer)))
|
||
(with-temp-buffer
|
||
(set-buffer-multibyte nil)
|
||
(let ((tmp-buf (current-buffer)))
|
||
(with-current-buffer buf
|
||
(save-restriction
|
||
(widen)
|
||
;; Since encoding should always return more bytes than
|
||
;; there were chars, encoding all chars up to (+ byte pm)
|
||
;; guarantees the encoded result has at least `byte' bytes.
|
||
(encode-coding-region pm (min (point-max) (+ pm byte))
|
||
coding-system tmp-buf)))
|
||
(+ pm (length
|
||
(decode-coding-region (point-min)
|
||
(min (point-max) (+ pm byte))
|
||
coding-system t))))))))))))
|
||
|
||
(provide 'mule-util)
|
||
|
||
;; Local Variables:
|
||
;; coding: utf-8
|
||
;; End:
|
||
|
||
;;; mule-util.el ends here
|