kakoune/src/changes.hh

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#ifndef changes_hh_INCLUDED
#define changes_hh_INCLUDED
#include "buffer.hh"
#include "coord.hh"
namespace Kakoune
{
// This tracks position changes for changes that are done
// in a forward way (each change takes place at a position)
// *after* the previous one.
struct ForwardChangesTracker
{
BufferCoord cur_pos; // last change position at current modification
BufferCoord old_pos; // last change position at start
void update(const Buffer::Change& change);
void update(const Buffer& buffer, size_t& timestamp);
BufferCoord get_old_coord(BufferCoord coord) const;
BufferCoord get_new_coord(BufferCoord coord) const;
BufferCoord get_new_coord_tolerant(BufferCoord coord) const;
bool relevant(const Buffer::Change& change, BufferCoord old_coord) const;
};
const Buffer::Change* forward_sorted_until(const Buffer::Change* first, const Buffer::Change* last);
const Buffer::Change* backward_sorted_until(const Buffer::Change* first, const Buffer::Change* last);
template<typename RangeContainer>
void update_forward(ConstArrayView<Buffer::Change> changes, RangeContainer& ranges)
{
ForwardChangesTracker changes_tracker;
auto change_it = changes.begin();
auto advance_while_relevant = [&](const BufferCoord& pos) mutable {
while (change_it != changes.end() and changes_tracker.relevant(*change_it, pos))
changes_tracker.update(*change_it++);
};
for (auto& range : ranges)
{
auto& first = get_first(range);
auto& last = get_last(range);
advance_while_relevant(first);
first = changes_tracker.get_new_coord_tolerant(first);
advance_while_relevant(last);
last = changes_tracker.get_new_coord_tolerant(last);
}
}
template<typename RangeContainer>
void update_backward(ConstArrayView<Buffer::Change> changes, RangeContainer& ranges)
{
ForwardChangesTracker changes_tracker;
using ReverseIt = std::reverse_iterator<const Buffer::Change*>;
auto change_it = ReverseIt(changes.end());
auto change_end = ReverseIt(changes.begin());
auto advance_while_relevant = [&](const BufferCoord& pos) mutable {
while (change_it != change_end)
{
auto change = *change_it;
change.begin = changes_tracker.get_new_coord(change.begin);
change.end = changes_tracker.get_new_coord(change.end);
if (not changes_tracker.relevant(change, pos))
break;
changes_tracker.update(change);
++change_it;
}
};
for (auto& range : ranges)
{
auto& first = get_first(range);
auto& last = get_last(range);
advance_while_relevant(first);
first = changes_tracker.get_new_coord_tolerant(first);
advance_while_relevant(last);
last = changes_tracker.get_new_coord_tolerant(last);
}
}
}
#endif // changes_hh_INCLUDED