plugins/org.eclipse.viatra2.core2/src/org/eclipse/viatra2/natives/AdderFunction.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Andras Schmidt, Andras Balogh, Istvan Rath and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Andras Schmidt, Andras Balogh, Istvan Rath - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.natives;

// fqn: org.eclipse.viatra2.natives.AdderFun
import org.eclipse.viatra2.core.IModelSpace;
import org.eclipse.viatra2.errors.VPMRuntimeException;
import org.eclipse.viatra2.natives.NativeFunctionParameter.ParameterType;

/**
 * @author Istvan Rath
 * 
 */
@VIATRANativeFunction(name = "add", returns = { ParameterType.INTEGER,
		ParameterType.DOUBLE, ParameterType.STRING }, params = {
		@NativeFunctionParameter(name = "operand1", description = "first operand", type = {
				ParameterType.INTEGER, ParameterType.DOUBLE,
				ParameterType.STRING }),
		@NativeFunctionParameter(name = "operand2", description = "second operand", type = {
				ParameterType.INTEGER, ParameterType.DOUBLE,
				ParameterType.STRING }), }, remark = "Operand types need to be of the same type at run-time (integer+double combinations are allowed).")
public class AdderFunction implements ASMNativeFunction {

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.viatra2.natives.ASMNativeFunction#evaluate(org.eclipse.viatra2
	 * .core.IModelSpace, java.lang.String[])
	 */
	public Object evaluate(IModelSpace msp, Object[] params)
			throws VPMRuntimeException {
		if (params.length == 2) {
			if ((params[0] instanceof Integer)
					&& (params[1] instanceof Integer))
				return new Integer(((Integer) params[0]).intValue()
						+ ((Integer) params[1]).intValue());
			if ((params[0] instanceof Double) && (params[1] instanceof Double))
				return new Double(((Double) params[0]).doubleValue()
						+ ((Double) params[1]).doubleValue());
			if ((params[0] instanceof String) && (params[1] instanceof String))
				return params[0].toString() + params[1].toString();
			if ((params[0] instanceof Integer) && (params[1] instanceof Double))
				return new Double(((Integer) params[0]).intValue()
						+ ((Double) params[1]).doubleValue());
			if ((params[0] instanceof Double) && (params[1] instanceof Integer))
				return new Double(((Double) params[0]).doubleValue()
						+ ((Integer) params[1]).intValue());

			throw new VPMRuntimeException("Parameter type mismatch!");

		}
		throw new VPMRuntimeException("Parameter count mismatch!");
	}

	public String getName() {
		return "add"; // VTCL
	}

	public String getDescription() {
		return "adds the two parameters. Numbers are added, strings are concatenated.";
	}

	public String getID() {
		return this.getClass().getCanonicalName();
	}

}