public abstract class FilterSpans extends Spans
Spans
implementation wrapping another spans instance,
allowing to filter spans matches easily by implementing accept(org.apache.lucene.search.spans.Spans)
Modifier and Type | Class and Description |
---|---|
static class |
FilterSpans.AcceptStatus
Status returned from
accept(Spans) that indicates
whether a candidate match should be accepted, rejected, or rejected
and move on to the next document. |
Modifier and Type | Field and Description |
---|---|
protected Spans |
in
The wrapped spans instance.
|
NO_MORE_POSITIONS
NO_MORE_DOCS
Modifier | Constructor and Description |
---|---|
protected |
FilterSpans(Spans in)
Wrap the given
Spans . |
Modifier and Type | Method and Description |
---|---|
protected abstract FilterSpans.AcceptStatus |
accept(Spans candidate)
Returns YES if the candidate should be an accepted match,
NO if it should not, and NO_MORE_IN_CURRENT_DOC if iteration
should move on to the next document.
|
int |
advance(int target)
Advances to the first beyond the current whose document number is greater
than or equal to target, and returns the document number itself.
|
TwoPhaseIterator |
asTwoPhaseIterator()
Optional method: Return a
TwoPhaseIterator view of this
Scorer . |
void |
collect(SpanCollector collector)
Collect postings data from the leaves of the current Spans.
|
long |
cost()
Returns the estimated cost of this
DocIdSetIterator . |
int |
docID()
Returns the following:
-1 if DocIdSetIterator.nextDoc() or
DocIdSetIterator.advance(int) were not called yet. |
int |
endPosition()
Returns the end position for the current start position, or -1 when
Spans.nextStartPosition() was not yet called on the current doc. |
int |
nextDoc()
Advances to the next document in the set and returns the doc it is
currently on, or
DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the
set.NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior. |
int |
nextStartPosition()
Returns the next start position for the current doc.
|
float |
positionsCost()
Return an estimation of the cost of using the positions of
this
Spans for any single document, but only after
Spans.asTwoPhaseIterator() returned null . |
int |
startPosition()
Returns the start position in the current doc, or -1 when
Spans.nextStartPosition() was not yet called on the current doc. |
String |
toString() |
int |
width()
Return the width of the match, which is typically used to compute
the
slop factor . |
doCurrentSpans, doStartCurrentDoc
all, empty, slowAdvance
protected final Spans in
protected abstract FilterSpans.AcceptStatus accept(Spans candidate) throws IOException
IOException
public final int nextDoc() throws IOException
DocIdSetIterator
DocIdSetIterator.NO_MORE_DOCS
if there are no more docs in the
set.nextDoc
in class DocIdSetIterator
IOException
public final int advance(int target) throws IOException
DocIdSetIterator
DocIdSetIterator.NO_MORE_DOCS
if target
is greater than the highest document number in the set.
The behavior of this method is undefined when called with
target ≤ current
, or after the iterator has exhausted.
Both cases may result in unpredicted behavior.
When target > current
it behaves as if written:
int advance(int target) { int doc; while ((doc = nextDoc()) < target) { } return doc; }Some implementations are considerably more efficient than that.
NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS
for
efficiency by some Scorers. If your implementation cannot efficiently
determine that it should exhaust, it is recommended that you check for that
value in each call to this method.
advance
in class DocIdSetIterator
IOException
public final int docID()
DocIdSetIterator
-1
if DocIdSetIterator.nextDoc()
or
DocIdSetIterator.advance(int)
were not called yet.
DocIdSetIterator.NO_MORE_DOCS
if the iterator has exhausted.
docID
in class DocIdSetIterator
public final int nextStartPosition() throws IOException
Spans
Spans.NO_MORE_POSITIONS
.nextStartPosition
in class Spans
IOException
public final int startPosition()
Spans
Spans.nextStartPosition()
was not yet called on the current doc.
After the last start/end position at the current doc this returns Spans.NO_MORE_POSITIONS
.startPosition
in class Spans
public final int endPosition()
Spans
Spans.nextStartPosition()
was not yet called on the current doc.
After the last start/end position at the current doc this returns Spans.NO_MORE_POSITIONS
.endPosition
in class Spans
public int width()
Spans
slop factor
. It is only legal
to call this method when the iterator is on a valid doc ID and positioned.
The return value must be positive, and lower values means that the match is
better.public void collect(SpanCollector collector) throws IOException
Spans
Spans.nextStartPosition()
, and before
Spans.NO_MORE_POSITIONS
has been reached.collect
in class Spans
collector
- a SpanCollectorIOException
public final long cost()
DocIdSetIterator
DocIdSetIterator
.
This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.
cost
in class DocIdSetIterator
public final TwoPhaseIterator asTwoPhaseIterator()
Spans
TwoPhaseIterator
view of this
Scorer
. A return value of null
indicates that
two-phase iteration is not supported.asTwoPhaseIterator
in class Spans
Scorer.twoPhaseIterator()
public float positionsCost()
Spans
Spans
for any single document, but only after
Spans.asTwoPhaseIterator()
returned null
.
Otherwise this method should not be called.
The returned value is independent of the current document.positionsCost
in class Spans
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