internal void CheckSubst(ChildType cur)
{
parentstate ps = parents_.Peek();
if (ps.parent == null)
{
throw new ArgumentException("Can't substitute the root node");
}
IList proposed = (IList)subst_(cur);
// note: we only visit children if no substitution
// is performed.
if (proposed == null)
{
VisitChildren(cur);
}
else if (!ps.is_list && proposed.Count == 1)
{
ps.field.SetValue(ps.parent, proposed[0]);
}
else if (ps.is_list)
{
IList thelist = (IList)ps.field.GetValue(ps.parent);
thelist.RemoveAt(ps.pos);
for (int i = 0; i < proposed.Count; ++i)
{
thelist.Insert(ps.pos + i, proposed[i]); // may throw
}
}
}
internal void VisitChildren(object cur)
{
parents_.Push(new parentstate()
{
parent = cur, is_list = false
});
parentstate ps = parents_.Peek();
foreach (var f in TreeInfo.ChildEntries(cur))
{
ps.field = f;
gen.Visit(this, f.GetValue(cur), true);
}
ps.is_list = true;
foreach (var f in TreeInfo.ChildListEntries(cur))
{
ps.field = f;
ps.pos = 0;
var enumerator = (System.Collections.IList)f.GetValue(cur);
for (ps.pos = 0; ps.pos < enumerator.Count; ++ps.pos)
{
gen.Visit(this, enumerator[ps.pos], true);
}
}
parents_.Pop();
}
internal void CheckSubst(ChildType cur)
{
parentstate ps = parents_.Peek();
if (ps.parent == null)
{
throw new ArgumentException("Can't substitute the root node");
}
ChildType proposed = subst_(cur) as ChildType;
// note: we only visit children if no substitution
// is performed.
if (proposed == null)
{
VisitChildren(cur);
}
else if (!ps.is_list)
{
ps.field.SetValue(ps.parent, proposed);
}
else if (ps.is_list)
{
IList thelist = (IList)ps.field.GetValue(ps.parent);
thelist[ps.pos] = proposed;
}
}