public static bool Compare(Symbol a, Symbol b)
{
OperationSymbol op_a = a as OperationSymbol;
OperationSymbol op_b = b as OperationSymbol;
if(op_a == null || op_b == null) {
return false;
}
return !(op_a is GroupSymbol) && op_a.Precedence >= op_b.Precedence;
}
public static bool IsRight(Symbol symbol)
{
GroupSymbol group = symbol as GroupSymbol;
return group != null && group.Direction == GroupSymbol.GroupDirection.Right;
}
public InvalidOperandException(Symbol symbol) : base(symbol.ToString())
{
}
public virtual Symbol Evaluate(Symbol a, Symbol b)
{
if(a is VoidSymbol || b is VoidSymbol) {
throw new InvalidOperandException(a, b);
}
try {
return Evaluate((ValueSymbol)a, (ValueSymbol)b);
} catch {
throw new InvalidOperandException(a, b);
}
}
public InvalidOperandException(Symbol a, Symbol b) : base(String.Format("{0}, {1}", a, b))
{
}
