BitSet.java

package client.net.sf.saxon.ce.functions.codenorm;

/**
 *  Reimplementation of the JDK class BitSet, with heavily subsetted functionality.
 *  Handles a fixed-size bit set only; uses an int[] array rather than long[] as a concession
 *  to GWT.
 */
public class BitSet {

    private int[] words;

    public BitSet(int bits) {
        words = new int[(bits>>5) + 1];
    }

    /**
     * Set the n'th bit.
     * @param bit the bit to be set
     * @throws ArrayIndexOutOfBoundsException if n is negative or greater than the number of bits allocated
     * (rounded up to a multiple of 32)
     */

    public void set(int bit) {
        int n = bit>>5;
        words[n] |= (1<<(bit&0x1f));
    }

    /**
     * Get the value of the n'th bit
     * @param bit the bit to be read.
     * @return the value of the n'th bit, or false if n is outside the range of bits allocated.
     */

    public boolean get(int bit) {
        int n = bit>>5;
        if (n < 0 || n >= words.length) {
            return false;
        }
        return (words[n] & (1<<(bit&0x1f))) != 0;
    }
}

// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. 
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.