本文整理了Java中org.apache.lucene.util.automaton.Operations.optional()方法的一些代码示例，展示了Operations.optional()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Operations.optional()方法的具体详情如下：
包路径：org.apache.lucene.util.automaton.Operations
类名称：Operations
方法名：optional

Operations.optional介绍

[英]Returns an automaton that accepts the union of the empty string and the language of the given automaton. This may create a dead state.

Complexity: linear in number of states.
[中]

代码示例

代码示例来源：origin: org.apache.lucene/lucene-core

break;
case REGEXP_OPTIONAL:
 a = Operations.optional(exp1.toAutomatonInternal(automata,
  automaton_provider, maxDeterminizedStates));
 a = MinimizationOperations.minimize(a, maxDeterminizedStates);

代码示例来源：origin: harbby/presto-connectors

@Override
public Weight createWeight(IndexSearcher searcher, boolean needsScores) throws IOException {
 final CompletionWeight innerWeight = ((CompletionWeight) innerQuery.createWeight(searcher, needsScores));
 // if separators are preserved the fst contains a SEP_LABEL
 // behind each gap. To have a matching automaton, we need to
 // include the SEP_LABEL in the query as well
 Automaton optionalSepLabel = Operations.optional(Automata.makeChar(CompletionAnalyzer.SEP_LABEL));
 Automaton prefixAutomaton = Operations.concatenate(optionalSepLabel, innerWeight.getAutomaton());
 Automaton contextsAutomaton = Operations.concatenate(toContextAutomaton(contexts, matchAllContexts), prefixAutomaton);
 contextsAutomaton = Operations.determinize(contextsAutomaton, Operations.DEFAULT_MAX_DETERMINIZED_STATES);
 final Map<IntsRef, Float> contextMap = new HashMap<>(contexts.size());
 final TreeSet<Integer> contextLengths = new TreeSet<>();
 for (Map.Entry<IntsRef, ContextMetaData> entry : contexts.entrySet()) {
  ContextMetaData contextMetaData = entry.getValue();
  contextMap.put(entry.getKey(), contextMetaData.boost);
  contextLengths.add(entry.getKey().length);
 }
 int[] contextLengthArray = new int[contextLengths.size()];
 final Iterator<Integer> iterator = contextLengths.descendingIterator();
 for (int i = 0; iterator.hasNext(); i++) {
  contextLengthArray[i] = iterator.next();
 }
 return new ContextCompletionWeight(this, contextsAutomaton, innerWeight, contextMap, contextLengthArray);
}

代码示例来源：origin: org.infinispan/infinispan-embedded-query

break;
case REGEXP_OPTIONAL:
 a = Operations.optional(exp1.toAutomatonInternal(automata,
  automaton_provider, maxDeterminizedStates));
 a = MinimizationOperations.minimize(a, maxDeterminizedStates);

代码示例来源：origin: harbby/presto-connectors

break;
case REGEXP_OPTIONAL:
 a = Operations.optional(exp1.toAutomatonInternal(automata,
  automaton_provider, maxDeterminizedStates));
 a = MinimizationOperations.minimize(a, maxDeterminizedStates);

代码示例来源：origin: org.apache.servicemix.bundles/org.apache.servicemix.bundles.lucene

break;
case REGEXP_OPTIONAL:
 a = Operations.optional(exp1.toAutomatonInternal(automata,
  automaton_provider, maxDeterminizedStates));
 a = MinimizationOperations.minimize(a, maxDeterminizedStates);