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Commit ee547125 authored by Miles Bader's avatar Miles Bader
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(find_field): Honor special `boundary' fields. 

(Fconstrain_to_field): Add the INHIBIT-CAPTURE-PROPERTY argument.
  Use scan_buffer instead of find_before_next_newline, because it
  allows us to detect the boundary case where there's a newline at
  the search limit.
(Qboundary): New variables.
(syms_of_editfns): Initialize Qboundary.
parent c28da489
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Showing with 119 additions and 78 deletions
src/editfns.c
View file @ ee547125
......@@ -337,14 +337,21 @@ char_property_stickiness (prop, pos)
/* Symbol for the text property used to mark fields. */
Lisp_Object Qfield;
/* A special value for Qfield properties. */
Lisp_Object Qboundary;
/* Find the field surrounding POS in *BEG and *END. If POS is nil,
the value of point is used instead.
If MERGE_AT_BOUNDARY is nonzero, then if POS is at the very first
position of a field, then the beginning of the previous field
is returned instead of the beginning of POS's field (since the end of
a field is actually also the beginning of the next input
field, this behavior is sometimes useful).
position of a field, then the beginning of the previous field is
returned instead of the beginning of POS's field (since the end of a
field is actually also the beginning of the next input field, this
behavior is sometimes useful). Additionally in the MERGE_AT_BOUNDARY
true case, if two fields are separated by a field with the special
value `boundary', and POS lies within it, then the two separated
fields are considered to be adjacent, and POS between them, when
finding the beginning and ending of the "merged" field.
Either BEG or END may be 0, in which case the corresponding value
is not stored. */
......@@ -355,84 +362,107 @@ find_field (pos, merge_at_boundary, beg, end)
Lisp_Object merge_at_boundary;
int *beg, *end;
{
/* Fields right before and after the point. */
Lisp_Object before_field, after_field;
/* 1 if POS counts as the start of a field. */
int at_field_start = 0;
/* 1 if POS counts as the end of a field. */
int at_field_end = 0;
if (NILP (pos))
XSETFASTINT (pos, PT);
else
CHECK_NUMBER_COERCE_MARKER (pos, 0);
if (NILP (merge_at_boundary) && XFASTINT (pos) > BEGV)
/* See if we need to handle the case where POS is at beginning of a
field, which can also be interpreted as the end of the previous
field. We decide which one by seeing which field the `field'
property sticks to. The case where if MERGE_AT_BOUNDARY is
non-nil (see function comment) is actually the more natural one;
then we avoid treating the beginning of a field specially. */
{
/* First see if POS is actually *at* a boundary. */
Lisp_Object after_field, before_field;
after_field = Fget_char_property (pos, Qfield, Qnil);
before_field = Fget_char_property (make_number (XINT (pos) - 1),
Qfield, Qnil);
if (! EQ (after_field, before_field))
/* We are at a boundary, see which direction is inclusive. */
after_field =
Fget_char_property (pos, Qfield, Qnil);
before_field =
(XFASTINT (pos) > BEGV
? Fget_char_property (make_number (XINT (pos) - 1), Qfield, Qnil)
: Qnil);
/* See if we need to handle the case where MERGE_AT_BOUNDARY is nil
and POS is at beginning of a field, which can also be interpreted
as the end of the previous field. Note that the case where if
MERGE_AT_BOUNDARY is non-nil (see function comment) is actually the
more natural one; then we avoid treating the beginning of a field
specially. */
if (NILP (merge_at_boundary) && !EQ (after_field, before_field))
/* We are at a boundary, see which direction is inclusive. We
decide by seeing which field the `field' property sticks to. */
{
int stickiness = char_property_stickiness (Qfield, pos);
if (stickiness > 0)
at_field_start = 1;
else if (stickiness < 0)
at_field_end = 1;
else
/* STICKINESS == 0 means that any inserted text will get a
`field' char-property of nil, so check to see if that
matches either of the adjacent characters (this being a
kind of "stickiness by default"). */
{
int stickiness = char_property_stickiness (Qfield, pos);
if (stickiness > 0)
at_field_start = 1;
else if (stickiness < 0)
at_field_end = 1;
else
/* STICKINESS == 0 means that any inserted text will get a
`field' char-property of nil, so check to see if that
matches either of the adjacent characters (this being a
kind of "stickiness by default"). */
{
if (NILP (before_field))
at_field_end = 1; /* Sticks to the left. */
else if (NILP (after_field))
at_field_start = 1; /* Sticks to the right. */
}
if (NILP (before_field))
at_field_end = 1; /* Sticks to the left. */
else if (NILP (after_field))
at_field_start = 1; /* Sticks to the right. */
}
}
/* Note about special `boundary' fields:
Consider the case where the point (`.') is between the fields `x' and `y':
xxxx.yyyy
In this situation, if merge_at_boundary is true, we consider the
`x' and `y' fields as forming one big merged field, and so the end
of the field is the end of `y'.
However, if `x' and `y' are separated by a special `boundary' field
(a field with a `field' char-property of 'boundary), then we ignore
this special field when merging adjacent fields. Here's the same
situation, but with a `boundary' field between the `x' and `y' fields:
xxx.BBBByyyy
Here, if point is at the end of `x', the beginning of `y', or
anywhere in-between (within the `boundary' field), we merge all
three fields and consider the beginning as being the beginning of
the `x' field, and the end as being the end of the `y' field. */
if (beg)
{
if (at_field_start)
/* POS is at the edge of a field, and we should consider it as
the beginning of the following field. */
*beg = XFASTINT (pos);
else
/* Find the previous field boundary. */
{
Lisp_Object prev;
prev =
Fprevious_single_char_property_change (pos, Qfield, Qnil, Qnil);
*beg = NILP (prev) ? BEGV : XFASTINT (prev);
}
}
if (at_field_start)
/* POS is at the edge of a field, and we should consider it as
the beginning of the following field. */
*beg = XFASTINT (pos);
else
/* Find the previous field boundary. */
{
if (!NILP (merge_at_boundary) && before_field == Qboundary)
/* Skip a `boundary' field. */
pos = Fprevious_single_char_property_change (pos, Qfield, Qnil,Qnil);
pos = Fprevious_single_char_property_change (pos, Qfield, Qnil, Qnil);
*beg = NILP (pos) ? BEGV : XFASTINT (pos);
}
if (end)
{
if (at_field_end)
/* POS is at the edge of a field, and we should consider it as
the end of the previous field. */
*end = XFASTINT (pos);
else
/* Find the next field boundary. */
{
Lisp_Object next;
next = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
*end = NILP (next) ? ZV : XFASTINT (next);
}
}
if (at_field_end)
/* POS is at the edge of a field, and we should consider it as
the end of the previous field. */
*end = XFASTINT (pos);
else
/* Find the next field boundary. */
{
if (!NILP (merge_at_boundary) && after_field == Qboundary)
/* Skip a `boundary' field. */
pos = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
pos = Fnext_single_char_property_change (pos, Qfield, Qnil, Qnil);
*end = NILP (pos) ? ZV : XFASTINT (pos);
}
}
DEFUN ("delete-field", Fdelete_field, Sdelete_field, 0, 1, 0,
......@@ -501,8 +531,9 @@ then the end of the *following* field is returned.")
return make_number (end);
}
DEFUN ("constrain-to-field", Fconstrain_to_field, Sconstrain_to_field, 2, 4, 0,
DEFUN ("constrain-to-field", Fconstrain_to_field, Sconstrain_to_field, 2, 5, 0,
"Return the position closest to NEW-POS that is in the same field as OLD-POS.\n\
\n\
A field is a region of text with the same `field' property.\n\
If NEW-POS is nil, then the current point is used instead, and set to the\n\
constrained position if that is is different.\n\
......@@ -513,7 +544,9 @@ ESCAPE-FROM-EDGE: If ESCAPE-FROM-EDGE is nil, then NEW-POS is\n\
constrained to the field that has the same `field' char-property\n\
as any new characters inserted at OLD-POS, whereas if ESCAPE-FROM-EDGE\n\
is non-nil, NEW-POS is constrained to the union of the two adjacent\n\
fields.\n\
fields. Additionally, if two fields are separated by another field with\n\
the special value `boundary', then any point within this special field is\n\
also considered to be `on the boundary'.\n\
\n\
If the optional argument ONLY-IN-LINE is non-nil and constraining\n\
NEW-POS would move it to a different line, NEW-POS is returned\n\
......@@ -521,9 +554,13 @@ unconstrained. This useful for commands that move by line, like\n\
\\[next-line] or \\[beginning-of-line], which should generally respect field boundaries\n\
only in the case where they can still move to the right line.\n\
\n\
If the optional argument INHIBIT-CAPTURE-PROPERTY is non-nil, and OLD-POS has\n\
a non-nil property of that name, then any field boundaries are ignored.\n\
\n\
Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.")
(new_pos, old_pos, escape_from_edge, only_in_line)
Lisp_Object new_pos, old_pos, escape_from_edge, only_in_line;
(new_pos, old_pos, escape_from_edge, only_in_line, inhibit_capture_property)
Lisp_Object new_pos, old_pos;
Lisp_Object escape_from_edge, only_in_line, inhibit_capture_property;
{
/* If non-zero, then the original point, before re-positioning. */
int orig_point = 0;
......@@ -537,11 +574,13 @@ Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.")
if (NILP (Vinhibit_field_text_motion)
&& !EQ (new_pos, old_pos)
&& !char_property_eq (Qfield, new_pos, old_pos))
&& !char_property_eq (Qfield, new_pos, old_pos)
&& (NILP (inhibit_capture_property)
|| NILP (Fget_char_property(old_pos, inhibit_capture_property, Qnil))))
/* NEW_POS is not within the same field as OLD_POS; try to
move NEW_POS so that it is. */
{
int fwd;
int fwd, shortage;
Lisp_Object field_bound;
CHECK_NUMBER_COERCE_MARKER (new_pos, 0);
......@@ -564,10 +603,10 @@ Field boundaries are not noticed if `inhibit-field-text-motion' is non-nil.")
|| ((XFASTINT (field_bound) < XFASTINT (new_pos)) ? !fwd : fwd)
/* If not, see if there's no newline intervening between
NEW_POS and FIELD_BOUND. */
|| (find_before_next_newline (XFASTINT (new_pos),
XFASTINT (field_bound),
fwd ? -1 : 1)
== XFASTINT (field_bound)))
|| (scan_buffer ('\n',
XFASTINT (new_pos), XFASTINT (field_bound),
fwd ? -1 : 1, &shortage, 1),
shortage != 0))
/* Constrain NEW_POS to FIELD_BOUND. */
new_pos = field_bound;
......@@ -610,7 +649,7 @@ This function does not move point.")
/* Return END constrained to the current input field. */
return Fconstrain_to_field (make_number (end), make_number (orig),
XINT (n) != 1 ? Qt : Qnil,
Qt);
Qt, Qnil);
}
DEFUN ("line-end-position", Fline_end_position, Sline_end_position,
......@@ -634,7 +673,7 @@ This function does not move point.")
/* Return END_POS constrained to the current input field. */
return Fconstrain_to_field (make_number (end_pos), make_number (orig),
Qnil, Qt);
Qnil, Qt, Qnil);
}
Lisp_Object
......@@ -3710,6 +3749,8 @@ functions if all the text being accessed has this property.");
staticpro (&Qfield);
Qfield = intern ("field");
staticpro (&Qboundary);
Qboundary = intern ("boundary");
defsubr (&Sfield_beginning);
defsubr (&Sfield_end);
defsubr (&Sfield_string);
......
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