private static void ToString(Expression x, StringBuilder sb)
{
if (x is OpNode)
{
OpNode o = (OpNode)x;
sb.Append("(");
ToString(o.leftChild, sb);
sb.Append(o.GetSymbol());
ToString(o.rightChild, sb);
sb.Append(")");
}
else
{
if (x is TermNode)
{
TermNode t = (TermNode)x;
if (t.GetNegate())
{
sb.Append("(");
sb.Append("-");
}
sb.Append(t.GetName());
if (t is FuncNode)
{
FuncNode f = (FuncNode)t;
sb.Append("(");
if (f.NumChildren() > 0)
{
ToString(f.Child(0), sb);
}
for (int i = 1; i < f.NumChildren(); i++)
{
sb.Append(", ");
ToString(f.Child(i), sb);
}
sb.Append(")");
}
if (t.GetNegate())
{
sb.Append(")");
}
}
else
{
if (x is ValNode)
{
sb.Append(((ValNode)x).val);
}
}
}
}
private static void GetTermNames(Expression x, Bag b, bool varNames)
{
if (x is OpNode)
{
OpNode o = (OpNode)x;
GetTermNames(o.leftChild, b, varNames);
GetTermNames(o.rightChild, b, varNames);
}
else
{
if (x is VarNode)
{
if (varNames)
{
VarNode v = (VarNode)x;
if (!b.Contains(v.name))
{
b.Add(v.name);
}
}
}
else
{
if (x is FuncNode)
{
FuncNode f = (FuncNode)x;
if (!varNames)
{
if (!b.Contains(f.name))
{
b.Add(f.name);
}
}
for (int i = 0; i < f.NumChildren(); i++)
{
GetTermNames(f.Child(i), b, varNames);
}
}
}
}
}