Delta.java

/*
 * Delta.java
 * Copyright 2001 (C) B. K. Oxley (binkley) <binkley@alumni.rice.edu>
 *
 * 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * Created on April 28, 2001, 8:34 AM
 */
package pcgen.util;

/**
 * A helper for {@code java.lang.Integer} which understands a
 * leading plus sign for string conversion.
 *
 * @author <a href="mailto:binkley@alumni.rice.edu">B. K. Oxley (binkley)</a>
 * @see java.lang.Integer
 */
public final class Delta
{
	private Delta()
	{
	}

	/**
	 * Construct a @see java.lang.Integer and strip a leading plus
	 * sign since {@code Integer} does not understand it.
	 * @param s
	 * @return Integer
	 */
	public static Integer decode(String s)
	{
		if ((!s.isEmpty()) && (s.charAt(0) == '+'))
		{
			s = s.substring(1);
		}

		return Integer.decode(s);
	}

	/**
	 * parse the Double
	 * @param s
	 * @return double
	 */
	public static double parseDouble(String s)
	{
		if (s.charAt(0) == '+')
		{
			s = s.substring(1);
		}

		return Double.parseDouble(s);
	}

	/**
	 * Parse a string with an option plus or minus followed by digits
	 * into an int.
	 * @param s a string that may or may not be a valid delta
	 * @return int
	 * @exception java.lang.NumberFormatException
	 * This exception is thrown if the string does not match the
	 * required format for a delta.
	 */
	public static int parseInt(String s)
	{
		if (s.charAt(0) == '+')
		{
			s = s.substring(1);
		}

		return Integer.parseInt(s);
	}

	/**
	 * toString
	 * @param v
	 * @return String
	 */
	public static String toString(Integer v)
	{
		return toString(v.intValue());
	}

	/**
	 * Returns a String representation of an integer value.  If the value is
	 * positive a plus sign (+) will be prepended.
	 * 
	 * @param v An integer to convert.
	 * 
	 * @return String value of integer.
	 */
	public static String toString(final int v)
	{
		if (v >= 0)
		{
			return "+" + v;
		}

		return String.valueOf(v);
	}

	/**
	 * toString
	 * @param v
	 * @return String
	 */
	public static String toString(Float v)
	{
		return toString(v.floatValue());
	}

	/**
	 * toString
	 * @param v
	 * @return String
	 */
	public static String toString(float v)
	{
		if (v >= 0.0)
		{
			return "+" + v;
		}

		return Float.toString(v);
	}
}