FinalBitSet (GraalVM Truffle Java API Reference)

java.lang.Object
- com.oracle.truffle.api.utilities.FinalBitSet

```
public final class FinalBitSet
extends Object
```
Read-only bitset designed for partial evaluation. The implementation is partially re-used from BitSet.

Since:

20.0

See Also:

BitSet

Field Summary

Fields
Modifier and Type Field and Description

static FinalBitSet EMPTY
An empty bit set of size 0.

Fields
Modifier and Type	Field and Description
`static FinalBitSet`	`EMPTY` An empty bit set of size 0.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`cardinality()` Returns the number of bits set to `true` in this `BitSet`.
`boolean`	`equals(Object obj)` Compares this object against the specified object.
`boolean`	`get(int bitIndex)` Returns the value of the bit with the specified index.
`int`	`hashCode()` Returns the hash code value for this bit set.
`boolean`	`isEmpty()` Returns true if this `FinalBitSet` contains no bits that are set to `true`.
`int`	`length()` Returns the "logical size" of this `FinalBitSet`: the index of the highest set bit in the `FinalBitSet` plus one.
`int`	`nextClearBit(int fromIndex)` Returns the index of the first bit that is set to `false` that occurs on or after the specified starting index.
`int`	`nextSetBit(int fromIndex)` Returns the index of the first bit that is set to `true` that occurs on or after the specified starting index.
`int`	`size()` Returns the number of bits of space actually in use by this `FinalBitSet` to represent bit values.
`long[]`	`toLongArray()` Returns a new long array containing all the bits in this bit set.
`String`	`toString()` Returns a string representation of this bit set.
`static FinalBitSet`	`valueOf(BitSet originalBitSet)` Returns a new final bit set from a Java `BitSet` instance.
`static FinalBitSet`	`valueOf(long[] longs)` Returns a new bit set containing all the bits in the given long array.

Methods inherited from class java.lang.Object
clone, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - EMPTY
```
public static final FinalBitSet EMPTY
```
    An empty bit set of size 0.
    
    Since:
    
    20.0
- Method Detail
  - toLongArray
```
public long[] toLongArray()
```
    Returns a new long array containing all the bits in this bit set. This method is designed for partial evaluation.
    More precisely, if
    long[] longs = s.toLongArray();
    then longs.length == (s.length()+63)/64 and
    s.get(n) == ((longs[n/64] & (1L<<(n%64))) != 0)
    for all n < 64 * longs.length.
    
    Returns:
    
    a long array containing a little-endian representation of all the bits in this bit set
    
    Since:
    
    20.0
  - get
```
public boolean get(int bitIndex)
```
    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 FinalBitSet; otherwise, the result is false. This method is designed for partial evaluation and is guaranteed to fold if the receiver and the bitIndex parameter are constant.
    
    Parameters:
    
    bitIndex - the bit index
    
    Returns:
    
    the value of the bit with the specified index
    
    Throws:
    
    IndexOutOfBoundsException - if the specified index is negative
    
    Since:
    
    20.0
  - length
```
public int length()
```
    Returns the "logical size" of this FinalBitSet: the index of the highest set bit in the FinalBitSet plus one. Returns zero if the FinalBitSet contains no set bits. This method is designed for partial evaluation and is guaranteed to fold if the receiver is constant.
    
    Returns:
    
    the logical size of this FinalBitSet
    
    Since:
    
    20.0
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if this FinalBitSet contains no bits that are set to true. This method is designed for partial evaluation and is guaranteed to fold if the receiver is constant.
    
    Returns:
    
    boolean indicating whether this FinalBitSet is empty
    
    Since:
    
    20.0
  - equals
```
public boolean equals(Object obj)
```
    Compares this object against the specified object. The result is true if and only if the argument is not null and is a FinalBitSet 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:
    
    equals in class Object
    
    Parameters:
    
    obj - the object to compare with
    
    Returns:
    
    true if the objects are the same; false otherwise
    
    Since:
    
    20.0
    
    See Also:
    
    FinalBitSet.size()
  - hashCode
```
public int hashCode()
```
    Returns the hash code value for this bit set. The hash code depends only on which bits are set within this FinalBitSet.
    The hash code is defined to be the result of the following calculation:
```
  
 public int hashCode() {
     long h = 1234;
     long[] words = toLongArray();
     for (int i = words.length; --i >= 0; )
         h ^= words[i] * (i + 1);
     return (int)((h >> 32) ^ h);
 }
 
```
    Note that the hash code changes if the set of bits is altered.
    Overrides:
    
    hashCode in class Object
    
    Returns:
    
    the hash code value for this bit set
    
    Since:
    
    20.0
  - size
```
public int size()
```
    Returns the number of bits of space actually in use by this FinalBitSet to represent bit values. The maximum element in the set is the size - 1st element. This method is designed for partial evaluation and is guaranteed to fold if the receiver is constant.
    
    Returns:
    
    the number of bits currently in this bit set
    
    Since:
    
    20.0
  - cardinality
```
public int cardinality()
```
    Returns the number of bits set to true in this BitSet.
    
    Returns:
    
    the number of bits set to true in this BitSet
    
    Since:
    
    20.0
  - nextSetBit
```
public int nextSetBit(int fromIndex)
```
    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 FinalBitSet, use the following loop:
```
  
 for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
     // operate on index i here
     if (i == Integer.MAX_VALUE) {
         break; // or (i+1) would overflow
     }
 }
 
```
    Parameters:
    
    fromIndex - the index to start checking from (inclusive)
    
    Returns:
    
    the index of the next set bit, or -1 if there is no such bit
    
    Throws:
    
    IndexOutOfBoundsException - if the specified index is negative
    
    Since:
    
    20.0
  - nextClearBit
```
public int nextClearBit(int fromIndex)
```
    Returns the index of the first bit that is set to false that occurs on or after the specified starting index.
    
    Parameters:
    
    fromIndex - the index to start checking from (inclusive)
    
    Returns:
    
    the index of the next clear bit
    
    Throws:
    
    IndexOutOfBoundsException - if the specified index is negative
    
    Since:
    
    20.0
  - toString
```
public String toString()
```
    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:
    
    toString in class Object
    
    Returns:
    
    a string representation of this bit set
    
    Since:
    
    20.0
    
    See Also:
    
    BitSet.toString()
  - valueOf
```
public static FinalBitSet valueOf(long[] longs)
```
    Returns a new bit set containing all the bits in the given long array.
    More precisely,
    FinalBitSet.valueOf(longs).get(n) == ((longs[n/64] & (1L<<(n%64))) != 0)
    for all n < 64 * longs.length.
    
    Parameters:
    
    longs - a long array containing a little-endian representation of a sequence of bits to be used as the initial bits of the new bit set
    
    Returns:
    
    a FinalBitSet containing all the bits in the long array
    
    Since:
    
    20.0
  - valueOf
```
public static FinalBitSet valueOf(BitSet originalBitSet)
```
    Returns a new final bit set from a Java BitSet instance. The original bit set will be copied.
    
    Since:
    
    20.0

Class FinalBitSet

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EMPTY

Method Detail

toLongArray

get

length

isEmpty

equals

hashCode

size

cardinality

nextSetBit

nextClearBit

toString

valueOf

valueOf