public final class WordDelimiterGraphFilter extends TokenFilter
PhraseQuery
can
work correctly when this filter is used in the search-time analyzer. Unlike
the deprecated WordDelimiterFilter
, this token filter produces a
correct token graph as output. However, it cannot consume an input token
graph correctly. Processing is suppressed by KeywordAttribute.isKeyword()
=true.
Words are split into subwords with the following rules:
"Wi-Fi"
→ "Wi", "Fi"
"PowerShot"
→
"Power", "Shot"
"SD500"
→
"SD", "500"
"//hello---there, 'dude'"
→
"hello", "there", "dude"
"O'Neil's"
→ "O", "Neil"
"PowerShot"
→ 0:"Power", 1:"Shot"
(0 and 1 are the token
positions)"PowerShot"
→
0:"Power", 1:"Shot" 1:"PowerShot"
"A's+B's&C's"
> 0:"A", 1:"B", 2:"C", 2:"ABC"
"Super-Duper-XL500-42-AutoCoder!"
→
0:"Super", 1:"Duper", 2:"XL", 2:"SuperDuperXL", 3:"500" 4:"42", 5:"Auto", 6:"Coder", 6:"AutoCoder"
WordDelimiterGraphFilter
is to help match words with different
subword delimiters. For example, if the source text contained "wi-fi" one may
want "wifi" "WiFi" "wi-fi" "wi+fi" queries to all match. One way of doing so
is to specify CATENATE options in the analyzer used for indexing, and not
in the analyzer used for querying. Given that
the current StandardTokenizer
immediately removes many intra-word
delimiters, it is recommended that this filter be used after a tokenizer that
does not do this (such as WhitespaceTokenizer
).Modifier and Type | Class and Description |
---|---|
private class |
WordDelimiterGraphFilter.PositionSorter |
(package private) class |
WordDelimiterGraphFilter.WordDelimiterConcatenation
A WDF concatenated 'run'
|
AttributeSource.State
Modifier and Type | Field and Description |
---|---|
private int |
accumPosInc |
private boolean |
adjustingOffsets |
private boolean |
adjustInternalOffsets |
private int |
bufferedLen |
private int[] |
bufferedParts |
private int |
bufferedPos |
private char[][] |
bufferedTermParts |
static int |
CATENATE_ALL
Causes all subword parts to be catenated:
|
static int |
CATENATE_NUMBERS
Causes maximum runs of number parts to be catenated:
|
static int |
CATENATE_WORDS
Causes maximum runs of word parts to be catenated:
|
private WordDelimiterGraphFilter.WordDelimiterConcatenation |
concat |
private WordDelimiterGraphFilter.WordDelimiterConcatenation |
concatAll |
private int |
flags |
static int |
GENERATE_NUMBER_PARTS
Causes number subwords to be generated:
|
static int |
GENERATE_WORD_PARTS
Causes parts of words to be generated:
|
static int |
IGNORE_KEYWORDS
Suppresses processing terms with
KeywordAttribute.isKeyword() =true. |
private WordDelimiterIterator |
iterator |
private KeywordAttribute |
keywordAttribute |
private int |
lastConcatCount |
private int |
lastStartOffset |
private OffsetAttribute |
offsetAttribute |
private PositionIncrementAttribute |
posIncAttribute |
private PositionLengthAttribute |
posLenAttribute |
static int |
PRESERVE_ORIGINAL
Causes original words are preserved and added to the subword list (Defaults to false)
|
(package private) CharArraySet |
protWords
If not null is the set of tokens to protect from being delimited
|
private int |
savedEndOffset |
private int |
savedStartOffset |
private AttributeSource.State |
savedState |
private char[] |
savedTermBuffer |
private int |
savedTermLength |
(package private) WordDelimiterGraphFilter.PositionSorter |
sorter |
static int |
SPLIT_ON_CASE_CHANGE
Causes lowercase -> uppercase transition to start a new subword.
|
static int |
SPLIT_ON_NUMERICS
If not set, causes numeric changes to be ignored (subwords will only be generated
given SUBWORD_DELIM tokens).
|
static int |
STEM_ENGLISH_POSSESSIVE
Causes trailing "'s" to be removed for each subword
|
private CharTermAttribute |
termAttribute |
private int |
wordPos |
input
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
Constructor and Description |
---|
WordDelimiterGraphFilter(TokenStream in,
boolean adjustInternalOffsets,
byte[] charTypeTable,
int configurationFlags,
CharArraySet protWords)
Creates a new WordDelimiterGraphFilter
|
WordDelimiterGraphFilter(TokenStream in,
int configurationFlags,
CharArraySet protWords)
Creates a new WordDelimiterGraphFilter using
WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTable |
Modifier and Type | Method and Description |
---|---|
(package private) void |
buffer(char[] termPart,
int startPos,
int endPos,
int startPart,
int endPart)
a null termPart means it's a simple slice of the original term
|
(package private) void |
buffer(int startPos,
int endPos,
int startPart,
int endPart)
startPos, endPos -> graph start/end position
startPart, endPart -> slice of the original term for this part
|
private void |
bufferWordParts()
Iterates all words parts and concatenations, buffering up the term parts we should return.
|
private void |
concatenate(WordDelimiterGraphFilter.WordDelimiterConcatenation concatenation)
Concatenates the saved buffer to the given WordDelimiterConcatenation
|
static java.lang.String |
flagsToString(int flags)
Returns string representation of configuration flags
|
private void |
flushConcatenation(WordDelimiterGraphFilter.WordDelimiterConcatenation concat)
Flushes the given WordDelimiterConcatenation by either writing its concat and then clearing, or just clearing.
|
private boolean |
has(int flag)
Determines whether the given flag is set
|
boolean |
incrementToken()
Consumers (i.e.,
IndexWriter ) use this method to advance the stream to
the next token. |
void |
reset()
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken() . |
private void |
saveState()
Saves the existing attribute states
|
private boolean |
shouldConcatenate(int wordType)
Determines whether to concatenate a word or number if the current word is the given type
|
private boolean |
shouldGenerateParts(int wordType)
Determines whether a word/number part should be generated for a word of the given type
|
java.lang.String |
toString()
Returns a string consisting of the class's simple name, the hex representation of the identity hash code,
and the current reflection of all attributes.
|
close, end
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState
public static final int GENERATE_WORD_PARTS
"PowerShot" => "Power" "Shot"
public static final int GENERATE_NUMBER_PARTS
"500-42" => "500" "42"
public static final int CATENATE_WORDS
"wi-fi" => "wifi"
public static final int CATENATE_NUMBERS
"500-42" => "50042"
public static final int CATENATE_ALL
"wi-fi-4000" => "wifi4000"
public static final int PRESERVE_ORIGINAL
"500-42" => "500" "42" "500-42"
public static final int SPLIT_ON_CASE_CHANGE
public static final int SPLIT_ON_NUMERICS
public static final int STEM_ENGLISH_POSSESSIVE
"O'Neil's" => "O", "Neil"
public static final int IGNORE_KEYWORDS
KeywordAttribute.isKeyword()
=true.final CharArraySet protWords
private final int flags
private int[] bufferedParts
private int bufferedLen
private int bufferedPos
private char[][] bufferedTermParts
private final CharTermAttribute termAttribute
private final KeywordAttribute keywordAttribute
private final OffsetAttribute offsetAttribute
private final PositionIncrementAttribute posIncAttribute
private final PositionLengthAttribute posLenAttribute
private final WordDelimiterIterator iterator
private final WordDelimiterGraphFilter.WordDelimiterConcatenation concat
private final boolean adjustInternalOffsets
private int lastConcatCount
private final WordDelimiterGraphFilter.WordDelimiterConcatenation concatAll
private int accumPosInc
private char[] savedTermBuffer
private int savedTermLength
private int savedStartOffset
private int savedEndOffset
private AttributeSource.State savedState
private int lastStartOffset
private boolean adjustingOffsets
private int wordPos
final WordDelimiterGraphFilter.PositionSorter sorter
public WordDelimiterGraphFilter(TokenStream in, boolean adjustInternalOffsets, byte[] charTypeTable, int configurationFlags, CharArraySet protWords)
in
- TokenStream to be filteredadjustInternalOffsets
- if the offsets of partial terms should be adjustedcharTypeTable
- table containing character typesconfigurationFlags
- Flags configuring the filterprotWords
- If not null is the set of tokens to protect from being delimitedpublic WordDelimiterGraphFilter(TokenStream in, int configurationFlags, CharArraySet protWords)
WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTablein
- TokenStream to be filteredconfigurationFlags
- Flags configuring the filterprotWords
- If not null is the set of tokens to protect from being delimitedprivate void bufferWordParts() throws java.io.IOException
java.io.IOException
public boolean incrementToken() throws java.io.IOException
TokenStream
IndexWriter
) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpl
s with the attributes of the next
token.
The producer must make no assumptions about the attributes after the method
has been returned: the caller may arbitrarily change it. If the producer
needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.
This method is called for every token of a document, so an efficient
implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
and AttributeSource.getAttribute(Class)
,
references to all AttributeImpl
s that this stream uses should be
retrieved during instantiation.
To ensure that filters and consumers know which attributes are available,
the attributes must be added during instantiation. Filters and consumers
are not required to check for availability of attributes in
TokenStream.incrementToken()
.
incrementToken
in class TokenStream
java.io.IOException
public void reset() throws java.io.IOException
TokenFilter
TokenStream.incrementToken()
.
Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call super.reset()
, otherwise
some internal state will not be correctly reset (e.g., Tokenizer
will
throw IllegalStateException
on further usage).
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.reset()
when overriding this method.
reset
in class TokenFilter
java.io.IOException
void buffer(int startPos, int endPos, int startPart, int endPart)
void buffer(char[] termPart, int startPos, int endPos, int startPart, int endPart)
private void saveState()
private void flushConcatenation(WordDelimiterGraphFilter.WordDelimiterConcatenation concat)
concat
- WordDelimiterConcatenation that will be flushedprivate boolean shouldConcatenate(int wordType)
wordType
- Type of the current word used to determine if it should be concatenatedtrue
if concatenation should occur, false
otherwiseprivate boolean shouldGenerateParts(int wordType)
wordType
- Type of the word used to determine if a word/number part should be generatedtrue
if a word/number part should be generated, false
otherwiseprivate void concatenate(WordDelimiterGraphFilter.WordDelimiterConcatenation concatenation)
concatenation
- WordDelimiterConcatenation to concatenate the buffer toprivate boolean has(int flag)
flag
- Flag to see if settrue
if flag is setpublic static java.lang.String flagsToString(int flags)
public java.lang.String toString()
AttributeSource
toString
in class AttributeSource
AttributeSource.reflectAsString(boolean)