# Uses of Package
org.apache.lucene.util

- Packages that use org.apache.lucene.util
  Package | Description
  --- | ---
  org.apache.lucene.analysis | Text analysis.
  org.apache.lucene.analysis.standard | Fast, general-purpose grammar-based tokenizer `StandardTokenizer` implements the Word Break rules from the Unicode Text Segmentation algorithm, as specified in Unicode Standard Annex #29.
  org.apache.lucene.analysis.tokenattributes | General-purpose attributes for text analysis.
  org.apache.lucene.codecs | Codecs API: API for customization of the encoding and structure of the index.
  org.apache.lucene.codecs.compressing | Compressing helper classes.
  org.apache.lucene.codecs.lucene90 | Lucene 9.0 file format.
  org.apache.lucene.codecs.lucene90.blocktree | BlockTree terms dictionary.
  org.apache.lucene.codecs.lucene90.compressing | Lucene 9.0 compressing format.
  org.apache.lucene.codecs.lucene95 | Lucene 9.5 file format.
  org.apache.lucene.codecs.lucene99 | Lucene 9.9 file format.
  org.apache.lucene.codecs.perfield | Postings format that can delegate to different formats per-field.
  org.apache.lucene.document | The logical representation of a `Document` for indexing and searching.
  org.apache.lucene.index | Code to maintain and access indices.
  org.apache.lucene.search | Code to search indices.
  org.apache.lucene.search.comparators | Comparators, used to compare hits so as to determine their sort order when collecting the top results with `TopFieldCollector`.
  org.apache.lucene.store | Binary i/o API, used for all index data.
  org.apache.lucene.util | Some utility classes.
  org.apache.lucene.util.automaton | Finite-state automaton for regular expressions.
  org.apache.lucene.util.bkd | Block KD-tree, implementing the generic spatial data structure described in this paper.
  org.apache.lucene.util.fst | Finite state transducers
  org.apache.lucene.util.graph | Utility classes for working with token streams as graphs.
  org.apache.lucene.util.hnsw | Navigable Small-World graph, nominally Hierarchical but currently only has a single layer.
  org.apache.lucene.util.mutable | Comparable object wrappers
  org.apache.lucene.util.packed | Packed integer arrays and streams.
  org.apache.lucene.util.quantization | Provides quantization methods for scaling vector values to smaller data types and possibly fewer dimensions

- Classes in org.apache.lucene.util used by org.apache.lucene.analysis
  Class | Description
  --- | ---
  AttributeFactory | An AttributeFactory creates instances of `AttributeImpl`s.
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  IgnoreRandomChains | Annotation to not test a class or constructor with `TestRandomChains` integration test.
  ResourceLoader | Abstraction for loading resources (streams, files, and classes).
  Unwrappable | An object with this interface is a wrapper around another object (e.g., a filter with a delegate).
  Version | Use by certain classes to match version compatibility across releases of Lucene.

- Classes in org.apache.lucene.util used by org.apache.lucene.analysis.standard
  Class | Description
  --- | ---
  AttributeFactory | An AttributeFactory creates instances of `AttributeImpl`s.
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.

- Classes in org.apache.lucene.util used by org.apache.lucene.analysis.tokenattributes
  Class | Description
  --- | ---
  Attribute | Base interface for attributes.
  AttributeImpl | Base class for Attributes that can be added to a `AttributeSource`.
  AttributeReflector | This interface is used to reflect contents of `AttributeSource` or `AttributeImpl`.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefBuilder | A builder for `BytesRef` instances.

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Bits | Interface for Bitset-like structures.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  FixedBitSet | BitSet of fixed length (numBits), backed by accessible (`FixedBitSet.getBits()`) long[], accessed with an int index, implementing `Bits` and `DocIdSet`.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.compressing
  Class | Description
  --- | ---
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.lucene90
  Class | Description
  --- | ---
  Bits | Interface for Bitset-like structures.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.lucene90.blocktree
  Class | Description
  --- | ---
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.lucene90.compressing
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.lucene95
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Bits | Interface for Bitset-like structures.

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.lucene99
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Bits | Interface for Bitset-like structures.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.

- Classes in org.apache.lucene.util used by org.apache.lucene.codecs.perfield
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Bits | Interface for Bitset-like structures.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.

- Classes in org.apache.lucene.util used by org.apache.lucene.document
  Class | Description
  --- | ---
  ArrayUtil.ByteArrayComparator | Comparator for a fixed number of bytes.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].

- Classes in org.apache.lucene.util used by org.apache.lucene.index
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.
  Bits | Interface for Bitset-like structures.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefBuilder | A builder for `BytesRef` instances.
  BytesRefIterator | A simple iterator interface for `BytesRef` iteration.
  FixedBitSet | BitSet of fixed length (numBits), backed by accessible (`FixedBitSet.getBits()`) long[], accessed with an int index, implementing `Bits` and `DocIdSet`.
  InfoStream | Debugging API for Lucene classes such as `IndexWriter` and `SegmentInfos`.
  IOSupplier | This is a result supplier that is allowed to throw an IOException.
  LongValues | Abstraction over an array of longs.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.
  SuppressForbidden | Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field.
  Unwrappable | An object with this interface is a wrapper around another object (e.g., a filter with a delegate).
  Version | Use by certain classes to match version compatibility across releases of Lucene.

- Classes in org.apache.lucene.util used by org.apache.lucene.search
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Attribute | Base interface for attributes.
  AttributeImpl | Base class for Attributes that can be added to a `AttributeSource`.
  AttributeReflector | This interface is used to reflect contents of `AttributeSource` or `AttributeImpl`.
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.
  Bits | Interface for Bitset-like structures.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefIterator | A simple iterator interface for `BytesRef` iteration.
  Counter | Simple counter class
  IOSupplier | This is a result supplier that is allowed to throw an IOException.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.
  PriorityQueue | A priority queue maintains a partial ordering of its elements such that the least element can always be found in constant time.
  Unwrappable | An object with this interface is a wrapper around another object (e.g., a filter with a delegate).

- Classes in org.apache.lucene.util used by org.apache.lucene.search.comparators
  Class | Description
  --- | ---
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].

- Classes in org.apache.lucene.util used by org.apache.lucene.store
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  SuppressForbidden | Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field.

- Classes in org.apache.lucene.util used by org.apache.lucene.util
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  ArrayUtil.ByteArrayComparator | Comparator for a fixed number of bytes.
  Attribute | Base interface for attributes.
  AttributeFactory | An AttributeFactory creates instances of `AttributeImpl`s.
  AttributeImpl | Base class for Attributes that can be added to a `AttributeSource`.
  AttributeReflector | This interface is used to reflect contents of `AttributeSource` or `AttributeImpl`.
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.
  AttributeSource.State | This class holds the state of an AttributeSource.
  Bits | Interface for Bitset-like structures.
  BitSet | Base implementation for a bit set.
  ByteBlockPool | This class enables the allocation of fixed-size buffers and their management as part of a buffer array.
  ByteBlockPool.Allocator | Abstract class for allocating and freeing byte blocks.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefArray.IndexedBytesRefIterator | An extension of `BytesRefIterator` that allows retrieving the index of the current element
  BytesRefArray.SortState | Used to iterate the elements of an array in a given order.
  BytesRefBuilder | A builder for `BytesRef` instances.
  BytesRefComparator | Specialized `BytesRef` comparator that `StringSorter` has optimizations for.
  BytesRefHash.BytesStartArray | Manages allocation of the per-term addresses.
  BytesRefIterator | A simple iterator interface for `BytesRef` iteration.
  CharsRef | Represents char[], as a slice (offset + length) into an existing char[].
  CharsRefBuilder | A builder for `CharsRef` instances.
  Counter | Simple counter class
  DocIdSetBuilder.BulkAdder | Utility class to efficiently add many docs in one go.
  FileDeleter.MsgType | Types of messages this file deleter will broadcast REF: messages about reference FILE: messages about file
  FixedBitSet | BitSet of fixed length (numBits), backed by accessible (`FixedBitSet.getBits()`) long[], accessed with an int index, implementing `Bits` and `DocIdSet`.
  GroupVIntUtil.IntReader | Provides an abstraction for read int values, so that decoding logic can be reused in different DataInput.
  InfoStream | Debugging API for Lucene classes such as `IndexWriter` and `SegmentInfos`.
  IntBlockPool.Allocator | Abstract class for allocating and freeing int blocks.
  IntsRef | Represents int[], as a slice (offset + length) into an existing int[].
  IOUtils.IOConsumer | Deprecated, for removal: This API element is subject to removal in a future version. was replaced by `IOConsumer`.
  IOUtils.IOFunction | Deprecated, for removal: This API element is subject to removal in a future version. was replaced by `IOFunction`.
  LongBitSet | BitSet of fixed length (numBits), backed by accessible (`LongBitSet.getBits()`) long[], accessed with a long index.
  LongHeap | A min heap that stores longs; a primitive priority queue that like all priority queues maintains a partial ordering of its elements such that the least element can always be found in constant time.
  LongsRef | Represents long[], as a slice (offset + length) into an existing long[].
  LongValues | Abstraction over an array of longs.
  MSBRadixSorter | Radix sorter for variable-length strings.
  NamedSPILoader.NamedSPI | Interface to support `NamedSPILoader.lookup(String)` by name.
  OfflineSorter.BufferSize | A bit more descriptive unit for constructors.
  OfflineSorter.ByteSequencesReader | Utility class to read length-prefixed byte[] entries from an input.
  OfflineSorter.ByteSequencesWriter | Utility class to emit length-prefixed byte[] entries to an output stream for sorting.
  PagedBytes.PagedBytesDataInput | Input that transparently iterates over pages
  PagedBytes.PagedBytesDataOutput | Output that transparently spills to new pages as necessary
  PagedBytes.Reader | Provides methods to read BytesRefs from a frozen PagedBytes.
  QueryBuilder.TermAndBoost | Wraps a term and boost
  ResourceLoader | Abstraction for loading resources (streams, files, and classes).
  RoaringDocIdSet | `DocIdSet` implementation inspired from http://roaringbitmap.org/
  RoaringDocIdSet.Builder | A builder of `RoaringDocIdSet`s.
  RollingBuffer.Resettable | Implement to reset an instance
  Selector | An implementation of a selection algorithm, ie.
  Sorter | Base class for sorting algorithms implementations.
  SparseFixedBitSet | A bit set that only stores longs that have at least one bit which is set.
  SuppressForbidden | Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field.
  UnicodeUtil.UTF8CodePoint | Holds a codepoint along with the number of bytes required to represent it in UTF8
  Version | Use by certain classes to match version compatibility across releases of Lucene.
  VirtualMethod | A utility for keeping backwards compatibility on previously abstract methods (or similar replacements).
  WeakIdentityMap | Implements a combination of `WeakHashMap` and `IdentityHashMap`.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.automaton
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefBuilder | A builder for `BytesRef` instances.
  BytesRefIterator | A simple iterator interface for `BytesRef` iteration.
  IntsRef | Represents int[], as a slice (offset + length) into an existing int[].

- Classes in org.apache.lucene.util used by org.apache.lucene.util.bkd
  Class | Description
  --- | ---
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  FixedBitSet | BitSet of fixed length (numBits), backed by accessible (`FixedBitSet.getBits()`) long[], accessed with an int index, implementing `Bits` and `DocIdSet`.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.fst
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  BytesRef | Represents byte[], as a slice (offset + length) into an existing byte[].
  BytesRefBuilder | A builder for `BytesRef` instances.
  CharsRef | Represents char[], as a slice (offset + length) into an existing char[].
  IntsRef | Represents int[], as a slice (offset + length) into an existing int[].
  IntsRefBuilder | A builder for `IntsRef` instances.
  SuppressForbidden | Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.graph
  Class | Description
  --- | ---
  AttributeSource | An AttributeSource contains a list of different `AttributeImpl`s, and methods to add and get them.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.hnsw
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  Bits | Interface for Bitset-like structures.
  BitSet | Base implementation for a bit set.
  InfoStream | Debugging API for Lucene classes such as `IndexWriter` and `SegmentInfos`.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.mutable
  Class | Description
  --- | ---
  BytesRefBuilder | A builder for `BytesRef` instances.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.packed
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.
  LongsRef | Represents long[], as a slice (offset + length) into an existing long[].
  LongValues | Abstraction over an array of longs.

- Classes in org.apache.lucene.util used by org.apache.lucene.util.quantization
  Class | Description
  --- | ---
  Accountable | An object whose RAM usage can be computed.