org.apache.calcite.util

Class BitSets

java.lang.Object

org.apache.calcite.util.BitSets

public final class BitSets
extends Object

Utility functions for BitSet.

Method Summary

Methods

Modifier and Type	Method and Description
static SortedMap<Integer,BitSet>	closure(SortedMap<Integer,BitSet> equivalence) Computes the closure of a map from integers to bits.
static boolean	contains(BitSet set0, BitSet set1) Returns true if all bits set in the second parameter are also set in the first.
static boolean	contains(BitSet set0, ImmutableBitSet set1) Returns true if all bits set in the second parameter are also set in the first.
static BitSet	of(ImmutableIntList bits) Creates a BitSet with given bits set.
static BitSet	of(int... bits) Creates a bitset with given bits set.
static BitSet	of(Integer[] bits) Creates a BitSet with given bits set.
static BitSet	of(Iterable<? extends Number> bits) Creates a BitSet with given bits set.
static void	populate(BitSet bitSet, ImmutableIntList list) Populates a BitSet from an ImmutableIntList.
static void	populate(BitSet bitSet, Iterable<? extends Number> list) Populates a BitSet from an iterable, such as a list of integer.
static int	previousClearBit(BitSet bitSet, int fromIndex) Returns the previous clear bit.
static BitSet	range(int toIndex) Creates a BitSet with bits between 0 and toIndex set.
static BitSet	range(int fromIndex, int toIndex) Creates a bitset with bits from fromIndex (inclusive) to specified toIndex (exclusive) set to true.
static void	setAll(BitSet bitSet, Iterable<? extends Number> list) Sets all bits in a given BitSet corresponding to integers from a list.
static int[]	toArray(BitSet bitSet) Converts a BitSet to an array.
static Iterable<Integer>	toIter(BitSet bitSet) Returns an iterable over the bits in a bitmap that are set to '1'.
static Iterable<Integer>	toIter(ImmutableBitSet bitSet)
static IntList	toList(BitSet bitSet) Converts a bitset to a list.
static BitSet	union(BitSet set0, BitSet... sets) Returns a BitSet that is the union of the given BitSets.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

contains

public static boolean contains(BitSet set0,
               BitSet set1)

Returns true if all bits set in the second parameter are also set in the first. In other words, whether x is a super-set of y.

Parameters:

set0 - Containing bitmap

set1 - Bitmap to be checked

Returns:

Whether all bits in set1 are set in set0

contains

public static boolean contains(BitSet set0,
               ImmutableBitSet set1)

Returns true if all bits set in the second parameter are also set in the first. In other words, whether x is a super-set of y.

Parameters:

set0 - Containing bitmap

set1 - Bitmap to be checked

Returns:

Whether all bits in set1 are set in set0

toIter

public static Iterable<Integer> toIter(BitSet bitSet)

Returns an iterable over the bits in a bitmap that are set to '1'.

This allows you to iterate over a bit set using a 'foreach' construct. For instance:

BitSet bitSet;
for (int i : Util.toIter(bitSet)) {
print(i);
}

Parameters:

bitSet - Bit set

Returns:

Iterable

toIter

public static Iterable<Integer> toIter(ImmutableBitSet bitSet)

toList

public static IntList toList(BitSet bitSet)

Converts a bitset to a list.

The list is mutable, and future changes to the list do not affect the contents of the bit set.

Parameters:

bitSet - Bit set

Returns:

List of set bits

toArray

public static int[] toArray(BitSet bitSet)

Converts a BitSet to an array.

Parameters:

bitSet - Bit set

Returns:

Array of set bits

of

public static BitSet of(int... bits)

Creates a bitset with given bits set.

For example, of(0, 3) returns a bit set with bits {0, 3} set.

Parameters:

bits - Array of bits to set

Returns:

Bit set

of

public static BitSet of(Integer[] bits)

Creates a BitSet with given bits set.

For example, of(new Integer[] {0, 3}) returns a bit set with bits {0, 3} set.

Parameters:

bits - Array of bits to set

Returns:

Bit set

of

public static BitSet of(Iterable<? extends Number> bits)

Creates a BitSet with given bits set.

For example, of(Arrays.asList(0, 3)) returns a bit set with bits {0, 3} set.

Parameters:

bits - Collection of bits to set

Returns:

Bit set

of

public static BitSet of(ImmutableIntList bits)

Creates a BitSet with given bits set.

For example, of(ImmutableIntList.of(0, 3)) returns a bit set with bits {0, 3} set.

Parameters:

bits - Collection of bits to set

Returns:

Bit set

range

public static BitSet range(int fromIndex,
           int toIndex)

Creates a bitset with bits from fromIndex (inclusive) to specified toIndex (exclusive) set to true.

For example, range(0, 3) returns a bit set with bits {0, 1, 2} set.

Parameters:

fromIndex - Index of the first bit to be set.

toIndex - Index after the last bit to be set.

Returns:

Bit set

range

public static BitSet range(int toIndex)

Creates a BitSet with bits between 0 and toIndex set.

setAll

public static void setAll(BitSet bitSet,
          Iterable<? extends Number> list)

Sets all bits in a given BitSet corresponding to integers from a list.

union

public static BitSet union(BitSet set0,
           BitSet... sets)

Returns a BitSet that is the union of the given BitSets. Does not modify any of the inputs.

previousClearBit

public static int previousClearBit(BitSet bitSet,
                   int fromIndex)

Returns the previous clear bit.

Has same behavior as BitSet.previousClearBit(int), but that method does not exist before 1.7.

closure

public static SortedMap<Integer,BitSet> closure(SortedMap<Integer,BitSet> equivalence)

Computes the closure of a map from integers to bits.

The input must have an entry for each position.

Does not modify the input map or its bit sets.

populate

public static void populate(BitSet bitSet,
            Iterable<? extends Number> list)

Populates a BitSet from an iterable, such as a list of integer.

populate

public static void populate(BitSet bitSet,
            ImmutableIntList list)

Populates a BitSet from an ImmutableIntList.