java.util.BitSet Maven / Gradle / Ivy
/*
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This work corresponds to the API signatures of JSR 219: Foundation
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package java.util;
import java.io.*;
/**
* This class implements a vector of bits that grows as needed. Each
* component of the bit set has a boolean value. The
* bits of a BitSet are indexed by nonnegative integers.
* Individual indexed bits can be examined, set, or cleared. One
* BitSet may be used to modify the contents of another
* BitSet through logical AND, logical inclusive OR, and
* logical exclusive OR operations.
*
* By default, all bits in the set initially have the value
* false.
*
* Every bit set has a current size, which is the number of bits
* of space currently in use by the bit set. Note that the size is
* related to the implementation of a bit set, so it may change with
* implementation. The length of a bit set relates to logical length
* of a bit set and is defined independently of implementation.
*
* Unless otherwise noted, passing a null parameter to any of the
* methods in a BitSet will result in a
* NullPointerException.
*
* A BitSet is not safe for multithreaded use without
* external synchronization.
*
* @author Arthur van Hoff
* @author Michael McCloskey
* @version 1.46, 02/02/00
* @since JDK1.0
*/
public class BitSet implements Cloneable, Serializable
{
/**
* The bits in this BitSet. The ith bit is stored in bits[i/64] at
* bit position i % 64 (where bit position 0 refers to the least
* significant bit and 63 refers to the most significant bit).
* INVARIANT: The words in bits[] above unitInUse-1 are zero.
*
* @serial
*/
private long[] bits;
/* use serialVersionUID from JDK 1.0.2 for interoperability */
private static final long serialVersionUID = 7997698588986878753L;
/**
* Creates a new bit set. All bits are initially false.
*/
public BitSet() { }
/**
* Creates a bit set whose initial size is large enough to explicitly
* represent bits with indices in the range 0 through
* nbits-1. All bits are initially false.
*
* @param nbits the initial size of the bit set.
* @exception NegativeArraySizeException if the specified initial size
* is negative.
*/
public BitSet(int nbits) { }
/**
* Sets the bit at the specified index to to the complement of its
* current value.
*
* @param bitIndex the index of the bit to flip.
* @exception IndexOutOfBoundsException if the specified index is negative.
* @since 1.4
*/
public void flip(int bitIndex) { }
/**
* Sets each bit from the specified fromIndex(inclusive) to the
* specified toIndex(exclusive) to the complement of its current
* value.
*
* @param fromIndex index of the first bit to flip.
* @param toIndex index after the last bit to flip.
* @exception IndexOutOfBoundsException if fromIndex is negative,
* or toIndex is negative, or fromIndex is
* larger than toIndex.
* @since 1.4
*/
public void flip(int fromIndex, int toIndex) { }
/**
* Sets the bit at the specified index to true.
*
* @param bitIndex a bit index.
* @exception IndexOutOfBoundsException if the specified index is negative.
* @since JDK1.0
*/
public void set(int bitIndex) { }
/**
* Sets the bit at the specified index to the specified value.
*
* @param bitIndex a bit index.
* @param value a boolean value to set.
* @exception IndexOutOfBoundsException if the specified index is negative.
* @since 1.4
*/
public void set(int bitIndex, boolean value) { }
/**
* Sets the bits from the specified fromIndex(inclusive) to the
* specified toIndex(exclusive) to true.
*
* @param fromIndex index of the first bit to be set.
* @param toIndex index after the last bit to be set.
* @exception IndexOutOfBoundsException if fromIndex is negative,
* or toIndex is negative, or fromIndex is
* larger than toIndex.
* @since 1.4
*/
public void set(int fromIndex, int toIndex) { }
/**
* Sets the bits from the specified fromIndex(inclusive) to the
* specified toIndex(exclusive) to the specified value.
*
* @param fromIndex index of the first bit to be set.
* @param toIndex index after the last bit to be set
* @param value value to set the selected bits to
* @exception IndexOutOfBoundsException if fromIndex is negative,
* or toIndex is negative, or fromIndex is
* larger than toIndex.
* @since 1.4
*/
public void set(int fromIndex, int toIndex, boolean value) { }
/**
* Sets the bit specified by the index to false.
*
* @param bitIndex the index of the bit to be cleared.
* @exception IndexOutOfBoundsException if the specified index is negative.
* @since JDK1.0
*/
public void clear(int bitIndex) { }
/**
* Sets the bits from the specified fromIndex(inclusive) to the
* specified toIndex(exclusive) to false.
*
* @param fromIndex index of the first bit to be cleared.
* @param toIndex index after the last bit to be cleared.
* @exception IndexOutOfBoundsException if fromIndex is negative,
* or toIndex is negative, or fromIndex is
* larger than toIndex.
* @since 1.4
*/
public void clear(int fromIndex, int toIndex) { }
/**
* Sets all of the bits in this BitSet to false.
*
* @since 1.4
*/
public void clear() { }
/**
* Returns the value of the bit with the specified index. The value
* is true if the bit with the index bitIndex
* is currently set in this BitSet; otherwise, the result
* is false.
*
* @param bitIndex the bit index.
* @return the value of the bit with the specified index.
* @exception IndexOutOfBoundsException if the specified index is negative.
*/
public boolean get(int bitIndex) {
return false;
}
/**
* Returns a new BitSet composed of bits from this BitSet
* from fromIndex(inclusive) to toIndex(exclusive).
*
* @param fromIndex index of the first bit to include.
* @param toIndex index after the last bit to include.
* @return a new BitSet from a range of this BitSet.
* @exception IndexOutOfBoundsException if fromIndex is negative,
* or toIndex is negative, or fromIndex is
* larger than toIndex.
* @since 1.4
*/
public BitSet get(int fromIndex, int toIndex) {
return null;
}
/**
* Returns the index of the first bit that is set to true
* that occurs on or after the specified starting index. If no such
* bit exists then -1 is returned.
*
* To iterate over the true bits in a BitSet,
* use the following loop:
*
* for(int i=bs.nextSetBit(0); i>=0; i=bs.nextSetBit(i+1)) {
* // operate on index i here
* }
*
* @param fromIndex the index to start checking from (inclusive).
* @return the index of the next set bit.
* @throws IndexOutOfBoundsException if the specified index is negative.
* @since 1.4
*/
public int nextSetBit(int fromIndex) {
return 0;
}
/**
* Returns the index of the first bit that is set to false
* that occurs on or after the specified starting index.
*
* @param fromIndex the index to start checking from (inclusive).
* @return the index of the next clear bit.
* @throws IndexOutOfBoundsException if the specified index is negative.
* @since 1.4
*/
public int nextClearBit(int fromIndex) {
return 0;
}
/**
* Returns the "logical size" of this BitSet: the index of
* the highest set bit in the BitSet plus one. Returns zero
* if the BitSet contains no set bits.
*
* @return the logical size of this BitSet.
* @since 1.2
*/
public int length() {
return 0;
}
/**
* Returns true if this BitSet contains no bits that are set
* to true.
*
* @return boolean indicating whether this BitSet is empty.
* @since 1.4
*/
public boolean isEmpty() {
return false;
}
/**
* Returns true if the specified BitSet has any bits set to
* true that are also set to true in this
* BitSet.
*
* @param set BitSet to intersect with
* @return boolean indicating whether this BitSet intersects
* the specified BitSet.
* @since 1.4
*/
public boolean intersects(BitSet set) {
return false;
}
/**
* Returns the number of bits set to true in this
* BitSet.
*
* @return the number of bits set to true in this
* BitSet.
* @since 1.4
*/
public int cardinality() {
return 0;
}
/**
* Performs a logical AND of this target bit set with the
* argument bit set. This bit set is modified so that each bit in it
* has the value true if and only if it both initially
* had the value true and the corresponding bit in the
* bit set argument also had the value true.
*
* @param set a bit set.
*/
public void and(BitSet set) { }
/**
* Performs a logical OR of this bit set with the bit set
* argument. This bit set is modified so that a bit in it has the
* value true if and only if it either already had the
* value true or the corresponding bit in the bit set
* argument has the value true.
*
* @param set a bit set.
*/
public void or(BitSet set) { }
/**
* Performs a logical XOR of this bit set with the bit set
* argument. This bit set is modified so that a bit in it has the
* value true if and only if one of the following
* statements holds:
*
* - The bit initially has the value
true, and the
* corresponding bit in the argument has the value false.
* - The bit initially has the value
false, and the
* corresponding bit in the argument has the value true.
*
*
* @param set a bit set.
*/
public void xor(BitSet set) { }
/**
* Clears all of the bits in this BitSet whose corresponding
* bit is set in the specified BitSet.
*
* @param set the BitSet with which to mask this
* BitSet.
* @since JDK1.2
*/
public void andNot(BitSet set) { }
/**
* Returns a hash code value for this bit set. The has code
* depends only on which bits have been set within this
* BitSet. The algorithm used to compute it may
* be described as follows.
* Suppose the bits in the BitSet were to be stored
* in an array of long integers called, say,
* bits, in such a manner that bit k is
* set in the BitSet (for nonnegative values of
* k) if and only if the expression
*
((k>>6) < bits.length) && ((bits[k>>6] & (1L << (bit & 0x3F))) != 0)
* is true. Then the following definition of the hashCode
* method would be a correct implementation of the actual algorithm:
*
* public int hashCode() {
* long h = 1234;
* for (int i = bits.length; --i >= 0; ) {
* h ^= bits[i] * (i + 1);
* }
* return (int)((h >> 32) ^ h);
* }
* Note that the hash code values change if the set of bits is altered.
* Overrides the hashCode method of Object.
*
* @return a hash code value for this bit set.
*/
public int hashCode() {
return 0;
}
/**
* Returns the number of bits of space actually in use by this
* BitSet to represent bit values.
* The maximum element in the set is the size - 1st element.
*
* @return the number of bits currently in this bit set.
*/
public int size() {
return 0;
}
/**
* Compares this object against the specified object.
* The result is true if and only if the argument is
* not null and is a Bitset object that has
* exactly the same set of bits set to true as this bit
* set. That is, for every nonnegative int index k,
*
((BitSet)obj).get(k) == this.get(k)
* must be true. The current sizes of the two bit sets are not compared.
* Overrides the equals method of Object.
*
* @param obj the object to compare with.
* @return true if the objects are the same;
* false otherwise.
* @see java.util.BitSet#size()
*/
public boolean equals(Object obj) {
return false;
}
/**
* Cloning this BitSet produces a new BitSet
* that is equal to it.
* The clone of the bit set is another bit set that has exactly the
* same bits set to true as this bit set and the same
* current size.
*
Overrides the clone method of Object.
*
* @return a clone of this bit set.
* @see java.util.BitSet#size()
*/
public Object clone() {
return null;
}
/**
* Returns a string representation of this bit set. For every index
* for which this BitSet contains a bit in the set
* state, the decimal representation of that index is included in
* the result. Such indices are listed in order from lowest to
* highest, separated by ", " (a comma and a space) and
* surrounded by braces, resulting in the usual mathematical
* notation for a set of integers.
* Overrides the toString method of Object.
*
Example:
*
* BitSet drPepper = new BitSet();
* Now drPepper.toString() returns "{}".
*
* drPepper.set(2);
* Now drPepper.toString() returns "{2}".
*
* drPepper.set(4);
* drPepper.set(10);
* Now drPepper.toString() returns "{2, 4, 10}".
*
* @return a string representation of this bit set.
*/
public String toString() {
return null;
}
/**
* This override of readObject makes sure unitsInUse is set properly
* when deserializing a bitset
*
*/
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException
{ }
}