Example usage for org.apache.lucene.util.automaton Operations intersection

Introduction

In this page you can find the example usage for org.apache.lucene.util.automaton Operations intersection.

Prototype

static public Automaton intersection(Automaton a1, Automaton a2) 

Source Link

Document

Returns an automaton that accepts the intersection of the languages of the given automata.

Usage

From source file:org.opengrok.suggest.query.SuggesterRangeQuery.java

License:Open Source License

/** {@inheritDoc} */
@Override//from   w  w  w  .j a  v a  2  s .c  om
public TermsEnum getTermsEnumForSuggestions(final Terms terms) {
    if (terms == null) {
        return TermsEnum.EMPTY;
    }

    BytesRef prefix = getPrefix();
    if (prefix != null) {
        Automaton prefixAutomaton = PrefixQuery.toAutomaton(prefix);

        Automaton finalAutomaton;
        if (suggestPosition == SuggestPosition.LOWER) {
            Automaton binaryInt = Automata.makeBinaryInterval(getLowerTerm(), includesLower(), getUpperTerm(),
                    includesUpper());

            finalAutomaton = Operations.intersection(binaryInt, prefixAutomaton);
        } else {
            Automaton binaryInt = Automata.makeBinaryInterval(null, true, getLowerTerm(), !includesLower());

            finalAutomaton = Operations.minus(prefixAutomaton, binaryInt, Integer.MIN_VALUE);
        }

        CompiledAutomaton compiledAutomaton = new CompiledAutomaton(finalAutomaton);
        try {
            return compiledAutomaton.getTermsEnum(terms);
        } catch (IOException e) {
            logger.log(Level.WARNING, "Could not compile automaton for range suggestions", e);
        }
    }

    return TermsEnum.EMPTY;
}

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