IEnumerable <SpanTermQuery> WildcardTerms(IEnumerable <Term> terms, IndexReader reader)
{
if (!HasWildcards)
{
foreach (Term t in terms)
{
yield return(new SpanTermQuery(t));
}
}
else
{
int maxTerms = 1000;
foreach (Term t in terms)
{
var termEnum = new WildcardTermEnum(reader, t);
var term = termEnum.Term();
while (term != null)
{
if (--maxTerms < 0)
{
throw new Exception("Too many matches for wildcard query, please be more specific.");
}
yield return(new SpanTermQuery(term));
termEnum.Next();
term = termEnum.Term();
}
}
}
}
static void Main(string[] args)
{
RAMDirectory dir = new RAMDirectory();
IndexWriter iw = new IndexWriter(dir, new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30), IndexWriter.MaxFieldLength.UNLIMITED);
Document d = new Document();
Field f = new Field("text", "This is some erfand erftyas poliot polioasd poliasdas data to test the wild card term enums. Lets see how it works out.", Field.Store.YES, Field.Index.ANALYZED);
d.Add(f);
iw.AddDocument(d);
iw.Commit();
IndexReader reader = iw.GetReader();
QueryParser parser = new QueryParser(Lucene.Net.Util.Version.LUCENE_30, "text", new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30));
// parser.MultiTermRewriteMethod = MultiTermQuery.CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE;
Query q = parser.Parse("(poli* && erf*) && test* && (asd* || res*) && aterm");
Query q2 = parser.Parse("poli*");
//var rq = q.Rewrite(reader);
//ISet<Term> terms = new HashSet<Term>();
//rq.ExtractTerms(terms);
List <PrefixQuery> prefixQueries = null;
if (q is PrefixQuery)
{
prefixQueries = new List <PrefixQuery>();
prefixQueries.Add(q as PrefixQuery);
}
else if (q is BooleanQuery)
{
prefixQueries = ExtractQueries(q as BooleanQuery);
}
foreach (var pq in prefixQueries)
{
WildcardTermEnum termEnum = new WildcardTermEnum(reader, new Term(pq.Prefix.Field, pq.Prefix.Text + "*"));
if (termEnum.Term != null)
{
Console.WriteLine(termEnum.Term.Text);
}
while (termEnum.Next())
{
Console.WriteLine(termEnum.Term.Text);
}
}
Console.ReadLine();
}
