public override void setChild(int index, Token token) {
switch (index)
{
case 0:
variable = token as Variable;
break;
case 1:
expression = token;
break;
default:
throw new Exception("Invalid child index: " + index);
}
token.indexInParent = index;
token.parent = this;
}
public TokenTree simplify()
{
bool somethingDone;
do
{
somethingDone = false;
List<Token> tokens = ReverseBFS();
foreach (Token t in tokens)
{
if (t is Operator)
{
Token left = t.getChild(0);
Token right = t.getChild(1);
if(left is Variable && right is Variable)
{
if(left.name == right.name)
{
if(t.name == "AND" || t.name == "OR" || t.name == "IMPLIES")
{
somethingDone = true;
Token n = new Variable(name: left.name);
if (t.parent == null)
{
root = n;
}
else
{
t.parent.setChild(t.indexInParent, n);
}
}
}
}
}
}
} while (somethingDone);
return this;
}