public CurrentNodes(SyntaxNode root)
{
// there could be multiple nodes with same annotation if a tree is rewritten with
// same node injected multiple times.
var map = new SegmentedDictionary <SyntaxAnnotation, List <SyntaxNode> >();
foreach (var node in root.GetAnnotatedNodesAndTokens(IdAnnotationKind).Select(n => n.AsNode() !))
{
Debug.Assert(node is object);
foreach (var id in node.GetAnnotations(IdAnnotationKind))
{
List <SyntaxNode>?list;
if (!map.TryGetValue(id, out list))
{
list = new List <SyntaxNode>();
map.Add(id, list);
}
list.Add(node);
}
}
_idToNodeMap = map.ToImmutableSegmentedDictionary(kv => kv.Key, kv => (IReadOnlyList <SyntaxNode>)ImmutableArray.CreateRange(kv.Value));
}