1 files changed, 39 insertions, 0 deletions
diff --git a/nouveau/src/main/java/org/apache/couchdb/nouveau/lucene9/SimpleAsciiFoldingAnalyzer.java b/nouveau/src/main/java/org/apache/couchdb/nouveau/lucene9/SimpleAsciiFoldingAnalyzer.java
new file mode 100644
index 000000000..ae7e4c261
--- /dev/null
+++ b/nouveau/src/main/java/org/apache/couchdb/nouveau/lucene9/SimpleAsciiFoldingAnalyzer.java
@@ -0,0 +1,39 @@
+//
+// Licensed 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.
+
+package org.apache.couchdb.nouveau.lucene9;
+
+import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.Tokenizer;
+import org.apache.lucene.analysis.core.LetterTokenizer;
+import org.apache.lucene.analysis.core.LowerCaseFilter;
+import org.apache.lucene.analysis.miscellaneous.ASCIIFoldingFilter;
+
+class SimpleAsciiFoldingAnalyzer extends Analyzer {
+
+    SimpleAsciiFoldingAnalyzer() {
+    }
+
+    @Override
+    protected TokenStreamComponents createComponents(String fieldName) {
+        Tokenizer tokenizer = new LetterTokenizer();
+        return new TokenStreamComponents(tokenizer, new ASCIIFoldingFilter(new LowerCaseFilter(tokenizer)));
+    }
+
+    @Override
+    protected TokenStream normalize(String fieldName, TokenStream in) {
+        return new ASCIIFoldingFilter(new LowerCaseFilter(in));
+    }
+
+}