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comparison src/extents.c @ 468:20ae8821c23d

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[xemacs-hg @ 2001-04-13 09:11:17 by michaels] The Great Trunk Move from release-21-2.
author michaels
date Fri, 13 Apr 2001 09:11:46 +0000
parents c33ae14dd6d0
children 183866b06e0b
comparison
equal deleted inserted replaced
467:13d500863631 468:20ae8821c23d
3841 return Fdetach_extent (extent); 3841 return Fdetach_extent (extent);
3842 3842
3843 get_buffer_or_string_range_byte (buffer_or_string, start, end, &s, &e, 3843 get_buffer_or_string_range_byte (buffer_or_string, start, end, &s, &e,
3844 GB_ALLOW_PAST_ACCESSIBLE); 3844 GB_ALLOW_PAST_ACCESSIBLE);
3845 3845
3846 buffer_or_string_extent_info_force (buffer_or_string);
3846 set_extent_endpoints (ext, s, e, buffer_or_string); 3847 set_extent_endpoints (ext, s, e, buffer_or_string);
3847 return extent; 3848 return extent;
3848 } 3849 }
3849 3850
3850 3851
4572 extent_end (extent) < indice + closure->length) 4573 extent_end (extent) < indice + closure->length)
4573 abort (); 4574 abort ();
4574 #endif 4575 #endif
4575 4576
4576 /* The extent-adjustment code adjusted the extent's endpoints as if 4577 /* The extent-adjustment code adjusted the extent's endpoints as if
4577 they were markers -- endpoints at the gap (i.e. the insertion 4578 all extents were closed-open -- endpoints at the insertion point
4578 point) go to the left of the insertion point, which is correct 4579 remain unchanged. We need to fix the other kinds of extents:
4579 for [) extents. We need to fix the other kinds of extents. 4580
4580 4581 1. Start position of start-open extents needs to be moved.
4581 Note that both conditions below will hold for zero-length (] 4582
4582 extents at the gap. Zero-length () extents would get adjusted 4583 2. End position of end-closed extents needs to be moved.
4583 such that their start is greater than their end; we treat them 4584
4584 as [) extents. This is unfortunately an inelegant part of the 4585 Note that both conditions hold for zero-length (] extents at the
4585 extent model, but there is no way around it. */ 4586 insertion point. But under these rules, zero-length () extents
4587 would get adjusted such that their start is greater than their
4588 end; instead of allowing that, we treat them as [) extents by
4589 modifying condition #1 to not fire nothing when dealing with a
4590 zero-length open-open extent.
4591
4592 Existence of zero-length open-open extents is unfortunately an
4593 inelegant part of the extent model, but there is no way around
4594 it. */
4586 4595
4587 { 4596 {
4588 Memind new_start, new_end; 4597 Memind new_start = extent_start (extent);
4589 4598 Memind new_end = extent_end (extent);
4590 new_start = extent_start (extent); 4599
4591 new_end = extent_end (extent); 4600 if (indice == extent_start (extent) && extent_start_open_p (extent)
4592 if (indice == extent_start (extent) && extent_start_open_p (extent) && 4601 /* zero-length () extents are exempt; see comment above. */
4593 /* coerce zero-length () extents to [) */ 4602 && !(new_start == new_end && extent_end_open_p (extent))
4594 new_start != new_end) 4603 )
4595 new_start += closure->length; 4604 new_start += closure->length;
4596 if (indice == extent_end (extent) && !extent_end_open_p (extent)) 4605 if (indice == extent_end (extent) && !extent_end_open_p (extent))
4597 new_end += closure->length; 4606 new_end += closure->length;
4607
4598 set_extent_endpoints_1 (extent, new_start, new_end); 4608 set_extent_endpoints_1 (extent, new_start, new_end);
4599 } 4609 }
4600 4610
4601 return 0; 4611 return 0;
4602 } 4612 }