/*****************************************************************************
SQLJEP - Java SQL Expression Parser 0.2
November 1 2006
(c) Copyright 2006, Alexey Gaidukov
SQLJEP Author: Alexey Gaidukov
SQLJEP is based on JEP 2.24 (http://www.singularsys.com/jep/)
(c) Copyright 2002, Nathan Funk
See LICENSE.txt for license information.
*****************************************************************************/
package com.meidusa.amoeba.sqljep.function;
import java.math.BigDecimal;
import com.meidusa.amoeba.sqljep.function.PostfixCommand;
import com.meidusa.amoeba.sqljep.ASTFunNode;
import com.meidusa.amoeba.sqljep.JepRuntime;
import com.meidusa.amoeba.sqljep.ParseException;
public final class UMinus extends PostfixCommand {
final public int getNumberOfParameters() {
return 1;
}
public Comparable<?>[] evaluate(ASTFunNode node, JepRuntime runtime) throws ParseException {
node.childrenAccept(runtime.ev, null);
Comparable<?> param = runtime.stack.pop();
return new Comparable<?>[]{param};
}
public static Comparable<?> umin(Comparable<?> param) throws ParseException {
if (param == null) {
return null;
}
if (param instanceof String) {
param = parse((String)param);
}
if (param instanceof BigDecimal) { // BigInteger is not supported
return ((BigDecimal)param).negate();
}
if (param instanceof Double || param instanceof Float) {
return new Double(-((Number)param).doubleValue());
}
if (param instanceof Number) { // Long, Integer, Short, Byte
return new Long(-((Number)param).longValue());
}
throw new ParseException(WRONG_TYPE+" "+param.getClass());
}
public Comparable<?> getResult(Comparable<?>... comparables)
throws ParseException {
return umin(comparables[0]);
}
}