BitSet

JavaのBitSetみたいなのが必要だったので書いてみました。

function BitSet( defaultValue ) {
    this.value = defaultValue ? defaultValue : 0 ;
}
BitSet.prototype = {
    on:   function( index ) {
        if ( index < 0 || index >= 32 ) { throw "out of bounds." }
        this.value |= 1 << index;
        return this;
    },
    off:  function( index ) {
        if ( index < 0 || index >= 32 ) { throw "out of bounds." }
        this.value &= ~(1 << index);
        return this;
    },
    flip:  function( index ) {
        this.isOn(index) ? this.off(index) : this.on(index) ;
        return this;
    },

    isOn: function( index ) {
        if ( index < 0 || index >= 32 ) { throw "out of bounds." }
        return (this.value & (1 << index)) != 0;
    },
    equals: function( bitSet ) {
        return bitSet.value == this.value;
    },

    and :   function( bitSet ) {
        return new BitSet(this.value & bitSet.value);
    },
    or  :   function( bitSet ) {
        return new BitSet(this.value | bitSet.value);
    },
    xor :   function( bitSet ) {
        return new BitSet(this.value ^ bitSet.value);
    },
    not :   function() {
        return new BitSet(~this.value);
    },

    toString: function() {
        var str = "";
        for (var i=31; i >= 0; i-- ) {
            str += this.isOn(i) ? "1" : "0";
        }
        return str;
    }
}

文系?プログラマなのでこういうのは苦手です。変なことしてたらゴメンナサイ。一応テストケースも書きました。
→テストケースを実行

var BitSetTest = new YAHOO.tool.TestCase({

    name: "BitSetTest",

    setUp: function () {},
    tearDown: function () {},

    /**
     * toStringのテスト
     */
    testToString: function () {
        var assert = YAHOO.util.Assert;

        var b = new BitSet(0);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );

        b = new BitSet(1);
        assert.areEqual( "00000000000000000000000000000001", b.toString() );

        b = new BitSet(2);
        assert.areEqual( "00000000000000000000000000000010", b.toString() );

        b = new BitSet(3);
        assert.areEqual( "00000000000000000000000000000011", b.toString() );

        b = new BitSet();
        assert.areEqual( "00000000000000000000000000000000", b.toString() );
    },

    /**
     * equalsのテスト
     */
    testEquals: function () {
        var assert = YAHOO.util.Assert;

        var b  = new BitSet(0);
        var b2 = new BitSet(1);
        var b3 = new BitSet(3);

        assert.isTrue(  b.equals(  new BitSet(0) ) );
        assert.isFalse( b2.equals( new BitSet(0) ) );
        assert.isFalse( b3.equals( new BitSet(0) ) );

        assert.isFalse( b.equals(  new BitSet(0).on(0) ) );
        assert.isTrue(  b2.equals( new BitSet(0).on(0) ) );
        assert.isFalse( b3.equals( new BitSet(0).on(0) ) );

        assert.isFalse( b.equals(  new BitSet(0).on(1) ) );
        assert.isFalse( b2.equals( new BitSet(0).on(1) ) );
        assert.isFalse( b3.equals( new BitSet(0).on(1) ) );

        assert.isFalse( b.equals(  new BitSet(0).on(0).on(1) ) );
        assert.isFalse( b2.equals( new BitSet(0).on(0).on(1) ) );
        assert.isTrue(  b3.equals( new BitSet(0).on(0).on(1) ) );
    },

    /**
     * on,offのテスト
     */
    testOnOff: function () {
        var assert = YAHOO.util.Assert;

        var b = new BitSet(0);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );
        assert.areEqual( false, b.isOn(0), "1-1" );
        assert.areEqual( false, b.isOn(1), "1-2" );
        assert.areEqual( false, b.isOn(2), "1-3" );
        assert.areEqual( false, b.isOn(3), "1-4" );
        assert.areEqual( false, b.isOn(4), "1-5" );
        assert.areEqual( false, b.isOn(5), "1-6" );
        assert.areEqual( false, b.isOn(6), "1-7" );

        b.on(0);
        assert.areEqual( "00000000000000000000000000000001", b.toString() );
        assert.areEqual( true,  b.isOn(0), "2-1" );
        assert.areEqual( false, b.isOn(1), "2-2" );
        assert.areEqual( false, b.isOn(2), "2-3" );
        assert.areEqual( false, b.isOn(3), "2-4" );
        assert.areEqual( false, b.isOn(4), "2-5" );
        assert.areEqual( false, b.isOn(5), "2-6" );
        assert.areEqual( false, b.isOn(6), "2-7" );

        b.on(1);
        assert.areEqual( "00000000000000000000000000000011", b.toString() );
        assert.areEqual( true,  b.isOn(0), "3-1" );
        assert.areEqual( true,  b.isOn(1), "3-2" );
        assert.areEqual( false, b.isOn(2), "3-3" );
        assert.areEqual( false, b.isOn(3), "3-4" );
        assert.areEqual( false, b.isOn(4), "3-5" );
        assert.areEqual( false, b.isOn(5), "3-6" );
        assert.areEqual( false, b.isOn(6), "3-7" );

        b.on(5);
        assert.areEqual( "00000000000000000000000000100011", b.toString() );
        assert.areEqual( true,  b.isOn(0), "4-1" );
        assert.areEqual( true,  b.isOn(1), "4-2" );
        assert.areEqual( false, b.isOn(2), "4-3" );
        assert.areEqual( false, b.isOn(3), "4-4" );
        assert.areEqual( false, b.isOn(4), "4-5" );
        assert.areEqual( true,  b.isOn(5), "4-6" );
        assert.areEqual( false, b.isOn(6), "4-7" );

        b.off(0);
        assert.areEqual( "00000000000000000000000000100010", b.toString() );
        assert.areEqual( false, b.isOn(0), "5-1" );
        assert.areEqual( true,  b.isOn(1), "5-2" );
        assert.areEqual( false, b.isOn(2), "5-3" );
        assert.areEqual( false, b.isOn(3), "5-4" );
        assert.areEqual( false, b.isOn(4), "5-5" );
        assert.areEqual( true,  b.isOn(5), "5-6" );
        assert.areEqual( false, b.isOn(6), "5-7" );

        b.off(1);
        assert.areEqual( "00000000000000000000000000100000", b.toString() );
        assert.areEqual( false, b.isOn(0), "6-1" );
        assert.areEqual( false, b.isOn(1), "6-2" );
        assert.areEqual( false, b.isOn(2), "6-3" );
        assert.areEqual( false, b.isOn(3), "6-4" );
        assert.areEqual( false, b.isOn(4), "6-5" );
        assert.areEqual( true,  b.isOn(5), "6-6" );
        assert.areEqual( false, b.isOn(6), "6-7" );

        b.off(5);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );
        assert.areEqual( false, b.isOn(0), "7-1" );
        assert.areEqual( false, b.isOn(1), "7-2" );
        assert.areEqual( false, b.isOn(2), "7-3" );
        assert.areEqual( false, b.isOn(3), "7-4" );
        assert.areEqual( false, b.isOn(4), "7-5" );
        assert.areEqual( false, b.isOn(5), "7-6" );
        assert.areEqual( false, b.isOn(6), "7-7" );
    },

    /**
     * flipのテスト
     */
    testFlip: function () {
        var assert = YAHOO.util.Assert;

        var b = new BitSet(0);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );

        b.flip(0);
        assert.areEqual( "00000000000000000000000000000001", b.toString() );
        assert.areEqual( true,  b.isOn(0), "2-1" );
        assert.areEqual( false, b.isOn(1), "2-2" );
        assert.areEqual( false, b.isOn(2), "2-3" );
        assert.areEqual( false, b.isOn(3), "2-4" );
        assert.areEqual( false, b.isOn(4), "2-5" );
        assert.areEqual( false, b.isOn(5), "2-6" );
        assert.areEqual( false, b.isOn(6), "2-7" );

        b.flip(1);
        assert.areEqual( "00000000000000000000000000000011", b.toString() );
        assert.areEqual( true,  b.isOn(0), "3-1" );
        assert.areEqual( true,  b.isOn(1), "3-2" );
        assert.areEqual( false, b.isOn(2), "3-3" );
        assert.areEqual( false, b.isOn(3), "3-4" );
        assert.areEqual( false, b.isOn(4), "3-5" );
        assert.areEqual( false, b.isOn(5), "3-6" );
        assert.areEqual( false, b.isOn(6), "3-7" );

        b.flip(5);
        assert.areEqual( "00000000000000000000000000100011", b.toString() );
        assert.areEqual( true,  b.isOn(0), "4-1" );
        assert.areEqual( true,  b.isOn(1), "4-2" );
        assert.areEqual( false, b.isOn(2), "4-3" );
        assert.areEqual( false, b.isOn(3), "4-4" );
        assert.areEqual( false, b.isOn(4), "4-5" );
        assert.areEqual( true,  b.isOn(5), "4-6" );
        assert.areEqual( false, b.isOn(6), "4-7" );

        b.flip(0);
        assert.areEqual( "00000000000000000000000000100010", b.toString() );
        assert.areEqual( false, b.isOn(0), "5-1" );
        assert.areEqual( true,  b.isOn(1), "5-2" );
        assert.areEqual( false, b.isOn(2), "5-3" );
        assert.areEqual( false, b.isOn(3), "5-4" );
        assert.areEqual( false, b.isOn(4), "5-5" );
        assert.areEqual( true,  b.isOn(5), "5-6" );
        assert.areEqual( false, b.isOn(6), "5-7" );

        b.flip(1);
        assert.areEqual( "00000000000000000000000000100000", b.toString() );
        assert.areEqual( false, b.isOn(0), "6-1" );
        assert.areEqual( false, b.isOn(1), "6-2" );
        assert.areEqual( false, b.isOn(2), "6-3" );
        assert.areEqual( false, b.isOn(3), "6-4" );
        assert.areEqual( false, b.isOn(4), "6-5" );
        assert.areEqual( true,  b.isOn(5), "6-6" );
        assert.areEqual( false, b.isOn(6), "6-7" );

        b.flip(5);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );
        assert.areEqual( false, b.isOn(0), "7-1" );
        assert.areEqual( false, b.isOn(1), "7-2" );
        assert.areEqual( false, b.isOn(2), "7-3" );
        assert.areEqual( false, b.isOn(3), "7-4" );
        assert.areEqual( false, b.isOn(4), "7-5" );
        assert.areEqual( false, b.isOn(5), "7-6" );
        assert.areEqual( false, b.isOn(6), "7-7" );
    },

    /**
     * and,or,xor,notのテスト
     */
    testAndOr: function () {
        var assert = YAHOO.util.Assert;

        var b = new BitSet(0);
        assert.areEqual( "00000000000000000000000000000000", b.toString() );

        b = b.or( new BitSet(3) );
        assert.areEqual( "00000000000000000000000000000011", b.toString() );
        assert.areEqual( true,  b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b = b.or( new BitSet(9) );
        assert.areEqual( "00000000000000000000000000001011", b.toString() );
        assert.areEqual( true,  b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( true,  b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b = b.and( new BitSet(7) );
        assert.areEqual( "00000000000000000000000000000011", b.toString() );
        assert.areEqual( true,  b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b = b.and( new BitSet(2) );
        assert.areEqual( "00000000000000000000000000000010", b.toString() );
        assert.areEqual( false, b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b = b.xor( new BitSet(5) );
        assert.areEqual( "00000000000000000000000000000111", b.toString() );
        assert.areEqual( true,  b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( true,  b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b = b.xor( new BitSet(5) );
        assert.areEqual( "00000000000000000000000000000010", b.toString() );
        assert.areEqual( false, b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );

        b.on(2).on(4);
        assert.areEqual( "00000000000000000000000000010110", b.toString() );
        b = b.not();
        assert.areEqual( "11111111111111111111111111101001", b.toString() );
        assert.areEqual( true,  b.isOn(0) );
        assert.areEqual( false, b.isOn(1) );
        assert.areEqual( false, b.isOn(2) );
        assert.areEqual( true,  b.isOn(3) );
        assert.areEqual( false, b.isOn(4) );
        assert.areEqual( true,  b.isOn(5) );
        assert.areEqual( true,  b.isOn(6) );

        b = b.not();
        assert.areEqual( "00000000000000000000000000010110", b.toString() );
        assert.areEqual( false, b.isOn(0) );
        assert.areEqual( true,  b.isOn(1) );
        assert.areEqual( true,  b.isOn(2) );
        assert.areEqual( false, b.isOn(3) );
        assert.areEqual( true,  b.isOn(4) );
        assert.areEqual( false, b.isOn(5) );
        assert.areEqual( false, b.isOn(6) );
    }
});