public bool delete_interactive (ref TextIter start_iter, ref TextIter end_iter, bool default_editable)
Deletes all editable text in the given range.
Calls @delete for each editable sub-range of [
end are revalidated to point to the location of the last deleted range, or left untouched if no
text was deleted.
start of range to delete
end of range
whether the buffer is editable by default
whether some text was actually deleted