internal Enumerator(IndexStack <T> stack)
{
_stack = stack;
_version = stack._version;
_index = -2;
_currentElement = default(T);
}
private static IndexStack <SyntaxNodeInfo> GetChildren(
ISyntaxNode node,
IVisitationMap visitationMap)
{
var children = new IndexStack <SyntaxNodeInfo>();
visitationMap.ResolveChildren(node, children);
return(children);
}
public static void Accept(
this ISyntaxNode node,
ISyntaxNodeVisitor visitor,
IVisitationMap visitationMap)
{
if (node is null)
{
throw new ArgumentNullException(nameof(node));
}
if (visitor is null)
{
throw new ArgumentNullException(nameof(visitor));
}
if (visitationMap is null)
{
throw new ArgumentNullException(nameof(visitationMap));
}
var path = new IndexStack <object>();
var ancestors = new IndexStack <SyntaxNodeInfo>();
var ancestorNodes = new IndexStack <ISyntaxNode>();
var level = new IndexStack <IndexStack <SyntaxNodeInfo> >();
var root = new IndexStack <SyntaxNodeInfo>();
root.Push(new SyntaxNodeInfo(node, null));
level.Push(root);
int index = 0;
while (level.Count != 0)
{
bool isLeaving = level[index].Count == 0;
VisitorAction action = default;
SyntaxNodeInfo parent = default;
SyntaxNodeInfo current = default;
if (isLeaving)
{
if (index == 0)
{
break;
}
level.Pop();
ancestorNodes.Pop();
current = ancestors.Pop();
parent = ancestors.Count == 0
? default
: ancestors.Peek();
action = Leave(
visitor,
current.Node,
parent.Node,
path,
ancestorNodes);
if (current.Name != null)
{
path.Pop();
}
if (current.Index.HasValue)
{
path.Pop();
}
index--;
}
else
{
current = level[index].Pop();
if (current.Name != null)
{
path.Push(current.Name);
}
if (current.Index.HasValue)
{
path.Push(current.Index.Value);
}
action = Enter(
visitor,
current.Node,
parent.Node,
path,
ancestorNodes);
if (action == VisitorAction.Continue)
{
level.Push(GetChildren(current.Node, visitationMap));
}
else if (action == VisitorAction.Skip)
{
// TODO : replace with empty
level.Push(new IndexStack <SyntaxNodeInfo>());
}
parent = current;
ancestors.Push(current);
ancestorNodes.Push(current.Node);
index++;
}
if (action == VisitorAction.Break)
{
break;
}
}
level.Clear();
}
