/* Markers: examining, setting and killing.
Copyright (C) 1985 Free Software Foundation, Inc.
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 1, or (at your option)
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; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Operations on markers. */
DEFUN ("marker-buffer", Fmarker_buffer
, Smarker_buffer
, 1, 1, 0,
"Return the buffer that MARKER points into, or nil if none.\n\
Returns nil if MARKER points into a dead buffer.")
register Lisp_Object marker
;
register Lisp_Object buf
;
CHECK_MARKER (marker
, 0);
if (XMARKER (marker
)->buffer
)
XSET (buf
, Lisp_Buffer
, XMARKER (marker
)->buffer
);
/* Return marker's buffer only if it is not dead. */
if (!NULL (XBUFFER (buf
)->name
))
DEFUN ("marker-position", Fmarker_position
, Smarker_position
, 1, 1, 0,
"Return the position MARKER points at, as a character number.")
register Lisp_Object pos
;
register struct buffer
*buf
;
CHECK_MARKER (marker
, 0);
if (XMARKER (marker
)->buffer
)
buf
= XMARKER (marker
)->buffer
;
i
= XMARKER (marker
)->bufpos
;
if (i
> BUF_GPT (buf
) + BUF_GAP_SIZE (buf
))
else if (i
> BUF_GPT (buf
))
if (i
< BUF_BEG (buf
) || i
> BUF_Z (buf
))
DEFUN ("set-marker", Fset_marker
, Sset_marker
, 2, 3, 0,
"Position MARKER before character number NUMBER in BUFFER.\n\
BUFFER defaults to the current buffer.\n\
If NUMBER is nil, makes marker point nowhere.\n\
Then it no longer slows down editing in any buffer.\n\
Lisp_Object marker
, pos
, buffer
;
register struct buffer
*b
;
register struct Lisp_Marker
*m
;
CHECK_MARKER (marker
, 0);
/* If position is nil or a marker that points nowhere,
make this marker point nowhere. */
(XTYPE (pos
) == Lisp_Marker
&& !XMARKER (pos
)->buffer
))
if (XMARKER (marker
)->buffer
)
CHECK_NUMBER_COERCE_MARKER (pos
, 1);
CHECK_BUFFER (buffer
, 1);
/* If buffer is dead, set marker to point nowhere. */
if (XMARKER (marker
)->buffer
)
if (charno
< BUF_BEG (b
))
if (charno
> BUF_GPT (b
)) charno
+= BUF_GAP_SIZE (b
);
/* This version of Fset_marker won't let the position be outside the visible part. */
set_marker_restricted (marker
, pos
, buffer
)
Lisp_Object marker
, pos
, buffer
;
register struct buffer
*b
;
register struct Lisp_Marker
*m
;
CHECK_MARKER (marker
, 0);
/* If position is nil or a marker that points nowhere,
make this marker point nowhere. */
(XTYPE (pos
) == Lisp_Marker
&& !XMARKER (pos
)->buffer
))
if (XMARKER (marker
)->buffer
)
CHECK_NUMBER_COERCE_MARKER (pos
, 1);
CHECK_BUFFER (buffer
, 1);
/* If buffer is dead, set marker to point nowhere. */
if (XMARKER (marker
)->buffer
)
if (charno
< BUF_BEGV (b
))
if (charno
> BUF_GPT (b
))
charno
+= BUF_GAP_SIZE (b
);
/* This is called during garbage collection,
so we must be careful to ignore and preserve mark bits,
including those in chain fields of markers. */
register Lisp_Object marker
;
register Lisp_Object tail
, prev
, next
;
register struct buffer
*b
;
b
= XMARKER (marker
)->buffer
;
while (XSYMBOL (tail
) != XSYMBOL (Qnil
))
next
= XMARKER (tail
)->chain
;
if (XMARKER (marker
) == XMARKER (tail
))
/* Deleting first marker from the buffer's chain.
Crash if new first marker in chain does not say
it belongs to this buffer. */
if (!EQ (next
, Qnil
) && b
!= XMARKER (next
)->buffer
)
omark
= XMARKBIT (XMARKER (prev
)->chain
);
XMARKER (prev
)->chain
= next
;
XSETMARKBIT (XMARKER (prev
)->chain
, omark
);
XMARKER (marker
)->buffer
= 0;
register struct Lisp_Marker
*m
= XMARKER (marker
);
register struct buffer
*buf
= m
->buffer
;
register int i
= m
->bufpos
;
error ("Marker does not point anywhere");
if (i
> BUF_GPT (buf
) + BUF_GAP_SIZE (buf
))
else if (i
> BUF_GPT (buf
))
if (i
< BUF_BEG (buf
) || i
> BUF_Z (buf
))
DEFUN ("copy-marker", Fcopy_marker
, Scopy_marker
, 1, 1, 0,
"Return a new marker pointing at the same place as MARKER.\n\
If argument is a number, makes a new marker pointing\n\
at that position in the current buffer.")
register Lisp_Object marker
;
register Lisp_Object
new;
if (XTYPE (marker
) == Lisp_Int
||
XTYPE (marker
) == Lisp_Marker
)
Fset_marker (new, marker
,
((XTYPE (marker
) == Lisp_Marker
)
? Fmarker_buffer (marker
)
marker
= wrong_type_argument (Qinteger_or_marker_p
, marker
);
defsubr (&Smarker_position
);
defsubr (&Smarker_buffer
);