MaxCommand.java

package plugin.jepcommands;

import org.nfunk.jep.ParseException;
import pcgen.util.PCGenCommand;

import java.util.Stack;

/**
 * Deal with max() JEP command eg. {@literal max(12.6, 20) --> 20}
 */
public class MaxCommand extends PCGenCommand
{
	/**
	 * <p>
	 * Initializes the number of parameters to = -1, indicating a variable
	 * number of parameters.
	 * </p>
	 *
	 */
	public MaxCommand()
	{
		super();
		numberOfParameters = -1;
	}

	/**
	 * Gets the name of the function handled by this class.
	 * @return The name of the function.
	 */
    @Override
	public String getFunctionName()
	{
		return "MAX";
	}

	/**
	 * <p>
	 * Calculates the maximum of the parameters on the stack, all of which
	 * are assumed to be of type double.
	 * </p>
	 *
	 * @param stack
	 *            Stack of incoming arguments.
	 * @throws ParseException
	 */
	@SuppressWarnings("unchecked") //Uses JEP, which doesn't use generics
    @Override
	public void run(final Stack stack) throws ParseException
	{
		// Check if stack is null
		if (null == stack)
		{
			throw new ParseException("Stack argument null");
		}

        double result = 0;
		boolean first = true;
		int i = 0;

		// repeat summation for each one of the current parameters
		while (i < curNumberOfParameters)
		{
			// get the parameter from the stack
            final Object param = stack.pop();
            if (param instanceof Number)
			{
				// calculate the result
				if (first || ((Number) param).doubleValue() > result)
				{
					result = ((Number) param).doubleValue();
				}
			}
			else
			{
				throw new ParseException("Invalid parameter type");
			}
			first = false;

			i++;
		}

		// push the result on the inStack
		stack.push(result);
	}
}