/* Create a visitor that applies its argument v in topdown
* fashion until it fails, and subsequently applies its argument
* vFinally at the nodes where failure occurs.
*/
public TopDownWhile(IVisitor v, IVisitor vFinally)
: base(null, vFinally)
{
first = new Sequence(v, new All(this));
}
public DownUp(IVisitor down, IVisitor stop, IVisitor up)
: base(down, null)
{
then = new Sequence(new Choice(stop,new All(this)), up);
}
/* Create a visitor that applies its argument v in topdown
* fashion until it fails. Thus, traversal is cut off below
* the nodes where v fails.
*/
public TopDownWhile(IVisitor v)
: base(null, new Identity())
{
first = new Sequence(v, new All(this));
}
public DownUp(IVisitor down, IVisitor up)
: base(down, null)
{
then = new Sequence(new All(this), up);
}