1 files changed, 70 insertions, 0 deletions
diff --git a/src/core/Search/SingleTermEnum.cs b/src/core/Search/SingleTermEnum.cs
new file mode 100644
index 0000000..f80b8d3
--- /dev/null
+++ b/src/core/Search/SingleTermEnum.cs
@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System;
+using Lucene.Net.Index;
+
+namespace Lucene.Net.Search
+{
+    /// <summary>
+    /// Subclass of FilteredTermEnum for enumerating a single term.
+    /// <p/>
+    /// This can be used by <see cref="MultiTermQuery"/>s that need only visit one term,
+    /// but want to preserve MultiTermQuery semantics such as
+    /// <see cref="RewriteMethod"/>.
+    /// </summary>
+    public class SingleTermEnum : FilteredTermEnum
+    {
+        private Term singleTerm;
+        private bool _endEnum = false;
+
+        /// <summary>
+        /// Creates a new <c>SingleTermEnum</c>.
+        /// <p/>
+        /// After calling the constructor the enumeration is already pointing to the term,
+        ///  if it exists.
+        /// </summary>
+        public SingleTermEnum(IndexReader reader, Term singleTerm)
+        {
+            this.singleTerm = singleTerm;
+            SetEnum(reader.Terms(singleTerm));
+        }
+
+        public override float Difference()
+        {
+            return 1.0F;
+        }
+
+        public override bool EndEnum()
+        {
+            return _endEnum;
+        }
+
+        protected internal override bool TermCompare(Term term)
+        {
+            if (term.Equals(singleTerm))
+            {
+                return true;
+            }
+            else
+            {
+                _endEnum = true;
+                return false;
+            }
+        }
+    }
+}