public bool AppliesTo(MarkupElement originalElement, MarkupElement pipeElement)
{
//get the index of the element
int index = pipeElement.Index;
//odd/even?
if (p_Odd) { return index % 2 != 0; }
if (p_Even) { return index % 2 == 0; }
//substitute for n?
if (!p_HasNSubstitute) {
//index has to match the result of the calculation
return index == p_ExpressionResult;
}
//use the n substitute as an accumulator and
//see if the result of the expression
//matches the elements index.
ArithmeticSubstitute n = new ArithmeticSubstitute(
new ArithmeticOperand(0),
'n');
LinkedList<ArithmeticSubstitute> subs = new LinkedList<ArithmeticSubstitute>();
subs.AddLast(n);
for (int c = 0; c <= index; c++) {
n.Operand.setValue(c, false, true);
ArithmeticNumeric res = p_Expression.Calculate(subs);
if (res == index) { return true; }
}
//no match
return false;
}
private bool substituteExist(char name, LinkedList<ArithmeticSubstitute> subs, out ArithmeticSubstitute found)
{
found = default(ArithmeticSubstitute);
//look for the name
IEnumerator<ArithmeticSubstitute> e = subs.GetEnumerator();
while (e.MoveNext()) {
ArithmeticSubstitute current = e.Current;
if (current.Name == name) {
e.Dispose();
found = current;
return true;
}
}
//not found
e.Dispose();
return false;
}