data structures</h2>

<p>Data structures produced by the library should not be mutated
unless explicitly allowed, in general. This is slightly more strict in
4.0 than it was in earlier versions, which copied the position objects
returned by <a href="manual.html#getCursor"><code>getCursor</code></a>
for nebulous, historic reasons. In 4.0, mutating these
objects <em>will</em> corrupt your editor's selection.</p>

</section>

<section id=deprecated><h2>Deprecated interfaces dropped</h2>

<p>A few properties an