public INode Walk(WalkFunc fn)
{
// Visit this node
INode rewritten;
if (!fn(this, out rewritten))
{
return(rewritten);
}
var objectList = rewritten as ObjectList;
if (objectList == null)
{
throw new InvalidOperationException("Walk function returned wrong type");
}
// Visit the child nodes of this node
for (int i = 0; i < objectList.Items.Length; i++)
{
objectList.Items[i] = (ObjectItem)objectList.Items[i].Walk(fn);
}
INode _;
fn(null, out _);
return(objectList);
}
public INode Walk(WalkFunc fn)
{
// Visit this node
INode rewritten;
if (!fn(this, out rewritten))
{
return(rewritten);
}
var objectType = rewritten as ObjectType;
if (objectType == null)
{
throw new InvalidOperationException("Walk function returned wrong type");
}
// Visit the child node of this node
objectType._list = (ObjectList)objectType._list.Walk(fn);
INode _;
fn(null, out _);
return(objectType);
}
// Walk traverses an AST in depth-first order: It starts by calling fn(node);
// node must not be nil. If fn returns true, Walk invokes fn recursively for
// each of the non-nil children of node, followed by a call of fn(nil). The
// returned node of fn can be used to rewrite the passed node to fn.
public static INode Walk(INode node, WalkFunc fn)
{
var(rewritten, ok) = fn(node);
if (!ok)
{
return(rewritten);
}
switch (node)
{
case File n:
n.Node = Walk(n.Node, fn);
break;
case ObjectList n:
foreach (var(i, item) in n.Items.Range())
{
n.Items[i] = Walk(item, fn) as ObjectItem;
}
break;
case ObjectKey n:
// nothing to do
break;
case ObjectItem n:
foreach (var(i, k) in n.Keys.Range())
{
n.Keys[i] = Walk(k, fn) as ObjectKey;
}
if (n.Val != null)
{
n.Val = Walk(n.Val, fn);
}
break;
case LiteralType n:
// nothing to do
break;
case ListType n:
foreach (var(i, l) in n.List.Range())
{
n.List[i] = Walk(l, fn);
}
break;
case ObjectType n:
n.List = Walk(n.List, fn) as ObjectList;
break;
default:
// should we panic here?
Console.Error.WriteLine("unknown type: {0}", node.GetType());
break;
}
fn(null);
return(rewritten);
}
public INode Walk(WalkFunc fn)
{
// Visit this node
INode rewritten;
if (!fn(this, out rewritten))
{
return(rewritten);
}
var listType = rewritten as ListType;
if (listType == null)
{
throw new InvalidOperationException("Walk function returned wrong type");
}
// Visit the child nodes of this node
for (int i = 0; i < listType.List.Length; i++)
{
listType.List[i] = listType.List[i].Walk(fn);
}
INode _;
fn(null, out _);
return(listType);
}
public INode Walk(WalkFunc fn)
{
// Visit this node
INode rewritten;
if (!fn(this, out rewritten))
{
return(rewritten);
}
INode _;
fn(null, out _);
return(rewritten);
}
public INode Walk(WalkFunc fn)
{
throw new System.NotSupportedException();
}
