Expression DifferentiateSubtraction(Subtraction node)
{
return(new Subtraction
{
Left = Differentiate(node.Left),
Right = Differentiate(node.Right)
});
}
void CompileSubtraction(Subtraction node)
{
CompileVisitor(node.Left);
CompileVisitor(node.Right);
rpnStack.Add(new SubtractionOperator());
}
private static Expression SimplifySubtraction(Subtraction node)
{
/*Expression left = Simplify(node.Left);
* Expression right = Simplify(node.Right);
*
* if (left.Type == ExpressionType.Float)
* {
* Float nl = (Float)left;
* if (right.Type == ExpressionType.Float)
* {
* Float nr = (Float)right;
* return nl - nr;
* }
* if (nl.isZero())
* {
* return new Negation { InnerNode = right };
* }
* }
* if (right.Type == ExpressionType.Float)
* {
* Float nr = (Float)right;
*
* if (nr.isZero())
* {
* return left;
* }
* }
* return new Subtraction { Left = left, Right = right };*/
Stack <Expression> stack = new Stack <Expression>();
stack.Push(node);
List <Expression> operands = new List <Expression>();
List <Float> floats = new List <Float>();
while (stack.Count != 0)
{
Expression current = stack.Pop();
if (current.Type == ExpressionType.Addition)
{
stack.Push(Simplify((current as Addition).Right));
stack.Push(Simplify((current as Addition).Left));
}
else if (current.Type == ExpressionType.Subtraction)
{
stack.Push(Simplify(new Negation {
InnerNode = (current as Subtraction).Right
}));
stack.Push(Simplify((current as Subtraction).Left));
}
else if (current.Type == ExpressionType.Float)
{
floats.Add(current as Float);
}
else
{
operands.Add(current);
}
}
Expression root;
if (floats.Count > 0)
{
Float result = new Float {
Value = 0.0f
};
foreach (var fNode in floats)
{
result += fNode;
}
root = result;
if (result.IsZero())
{
if (operands.Count > 0)
{
root = operands[0];
operands.RemoveAt(0);
}
}
}
else
{
root = operands[0];
operands.RemoveAt(0);
}
foreach (var value in operands)
{
if (value is Negation)
{
root = new Subtraction {
Left = root, Right = (value as Negation).InnerNode
};
}
else
{
root = new Addition {
Left = root, Right = value
};
}
}
return(root);
}
