SynonymGraphFilter
instead, but be sure to also
use FlattenGraphFilter
at index time (not at search time) as well.@Deprecated public final class SynonymFilter extends TokenFilter
Note that with the current implementation, parsing is greedy, so whenever multiple parses would apply, the rule starting the earliest and parsing the most tokens wins. For example if you have these rules:
a -> x a b -> y b c d -> zThen input
a b c d e
parses to y b c
d
, ie the 2nd rule "wins" because it started
earliest and matched the most input tokens of other rules
starting at that point.
A future improvement to this filter could allow non-greedy parsing, such that the 3rd rule would win, and also separately allow multiple parses, such that all 3 rules would match, perhaps even on a rule by rule basis.
NOTE: when a match occurs, the output tokens
associated with the matching rule are "stacked" on top of
the input stream (if the rule had
keepOrig=true
) and also on top of another
matched rule's output tokens. This is not a correct
solution, as really the output should be an arbitrary
graph/lattice. For example, with the above match, you
would expect an exact PhraseQuery
"y b
c"
to match the parsed tokens, but it will fail to
do so. This limitation is necessary because Lucene's
TokenStream (and index) cannot yet represent an arbitrary
graph.
NOTE: If multiple incoming tokens arrive on the same position, only the first token at that position is used for parsing. Subsequent tokens simply pass through and are not parsed. A future improvement would be to allow these tokens to also be matched.
Modifier and Type | Class and Description |
---|---|
private static class |
SynonymFilter.PendingInput
Deprecated.
|
private static class |
SynonymFilter.PendingOutputs
Deprecated.
|
AttributeSource.State
Modifier and Type | Field and Description |
---|---|
private ByteArrayDataInput |
bytesReader
Deprecated.
|
private int |
captureCount
Deprecated.
|
private boolean |
finished
Deprecated.
|
private FST<BytesRef> |
fst
Deprecated.
|
private FST.BytesReader |
fstReader
Deprecated.
|
private SynonymFilter.PendingInput[] |
futureInputs
Deprecated.
|
private SynonymFilter.PendingOutputs[] |
futureOutputs
Deprecated.
|
private boolean |
ignoreCase
Deprecated.
|
private int |
inputSkipCount
Deprecated.
|
private int |
lastEndOffset
Deprecated.
|
private int |
lastStartOffset
Deprecated.
|
private int |
nextRead
Deprecated.
|
private int |
nextWrite
Deprecated.
|
private OffsetAttribute |
offsetAtt
Deprecated.
|
private PositionIncrementAttribute |
posIncrAtt
Deprecated.
|
private PositionLengthAttribute |
posLenAtt
Deprecated.
|
private int |
rollBufferSize
Deprecated.
|
private FST.Arc<BytesRef> |
scratchArc
Deprecated.
|
private BytesRef |
scratchBytes
Deprecated.
|
private CharsRefBuilder |
scratchChars
Deprecated.
|
private SynonymMap |
synonyms
Deprecated.
|
private CharTermAttribute |
termAtt
Deprecated.
|
static java.lang.String |
TYPE_SYNONYM
Deprecated.
|
private TypeAttribute |
typeAtt
Deprecated.
|
input
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
Constructor and Description |
---|
SynonymFilter(TokenStream input,
SynonymMap synonyms,
boolean ignoreCase)
Deprecated.
|
Modifier and Type | Method and Description |
---|---|
private void |
addOutput(BytesRef bytes,
int matchInputLength,
int matchEndOffset)
Deprecated.
|
private void |
capture()
Deprecated.
|
(package private) int |
getCaptureCount()
Deprecated.
|
boolean |
incrementToken()
Deprecated.
Consumers (i.e.,
IndexWriter ) use this method to advance the stream to
the next token. |
private void |
parse()
Deprecated.
|
void |
reset()
Deprecated.
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken() . |
private int |
rollIncr(int count)
Deprecated.
|
close, end
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
public static final java.lang.String TYPE_SYNONYM
private final SynonymMap synonyms
private final boolean ignoreCase
private final int rollBufferSize
private int captureCount
private final CharTermAttribute termAtt
private final PositionIncrementAttribute posIncrAtt
private final PositionLengthAttribute posLenAtt
private final TypeAttribute typeAtt
private final OffsetAttribute offsetAtt
private int inputSkipCount
private final SynonymFilter.PendingInput[] futureInputs
private final ByteArrayDataInput bytesReader
private final SynonymFilter.PendingOutputs[] futureOutputs
private int nextWrite
private int nextRead
private boolean finished
private final FST.BytesReader fstReader
private final BytesRef scratchBytes
private final CharsRefBuilder scratchChars
private int lastStartOffset
private int lastEndOffset
public SynonymFilter(TokenStream input, SynonymMap synonyms, boolean ignoreCase)
input
- input tokenstreamsynonyms
- synonym mapignoreCase
- case-folds input for matching with Character.toLowerCase(int)
.
Note, if you set this to true, it's your responsibility to lowercase
the input entries when you create the SynonymMap
private void capture()
private void parse() throws java.io.IOException
java.io.IOException
private void addOutput(BytesRef bytes, int matchInputLength, int matchEndOffset)
private int rollIncr(int count)
int getCaptureCount()
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