/**
* Copyright (C) 2010 dennis zhuang (killme2008@gmail.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
**/
package com.googlecode.aviator.runtime.function;
import java.util.Map;
import com.googlecode.aviator.exception.ExpressionRuntimeException;
import com.googlecode.aviator.runtime.type.AviatorFunction;
import com.googlecode.aviator.runtime.type.AviatorJavaType;
import com.googlecode.aviator.runtime.type.AviatorObject;
import com.googlecode.aviator.runtime.type.AviatorType;
/**
* Function helper
*
* @author dennis
*
*/
public class FunctionUtils {
public static final String getStringValue(int index, AviatorObject[] args, Map<String, Object> env) {
String result = null;
final Object value = args[index].getValue(env);
if (value == null && args[index].getAviatorType() == AviatorType.JavaType) {
throw new NullPointerException("There is no string named" + ((AviatorJavaType) args[index]).getName());
}
if (value instanceof Character) {
result = value.toString();
}
else {
result = (String) value;
}
return result;
}
public static Object getJavaObject(int index, AviatorObject[] args, Map<String, Object> env) {
final AviatorObject arg = args[index];
if (!(arg instanceof AviatorJavaType)) {
throw new ExpressionRuntimeException(arg.desc(env) + " is not a javaType");
}
return env.get(((AviatorJavaType) arg).getName());
}
public static AviatorFunction getFunction(int index, AviatorObject[] args, Map<String, Object> env, int arity) {
final AviatorObject arg = args[index];
if (!(arg instanceof AviatorJavaType)) {
throw new ExpressionRuntimeException(arg.desc(env) + " is not a function");
}
// special processing for "-" operator
String name = ((AviatorJavaType) arg).getName();
if (name.equals("-")) {
if (arity == 2) {
name = "-sub";
}
else {
name = "-neg";
}
}
return (AviatorFunction) env.get(name);
}
public static final Number getNumberValue(int index, AviatorObject[] args, Map<String, Object> env) {
return (Number) args[index].getValue(env);
}
}