Sorting unicode text with lucene

Program.cs

using ICU4N.Text;
using Lucene.Net.Analysis.Fr;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Analysis.TokenAttributes;
using Lucene.Net.Collation;
using Lucene.Net.Documents;
using Lucene.Net.Index;
using Lucene.Net.Search;
using Lucene.Net.Store;
using Lucene.Net.Util;
using System;
using System.Globalization;

namespace LuceneSort
{
    class Program
    {
        static void Main(string[] args)
        {
            // Ensures index backwards compatibility
            var AppLuceneVersion = LuceneVersion.LUCENE_48;

            var indexLocation = @"C:\temp\luceneindex";
            if (System.IO.Directory.Exists(indexLocation))
            {
                System.IO.Directory.Delete(indexLocation, true);
            }
            var dir = FSDirectory.Open(indexLocation);

            //create an analyzer to process the text
            //var analyzer = new StandardAnalyzer(AppLuceneVersion);

            var collator = Collator.GetInstance(new CultureInfo("fr"));
            var analyzer = new ICUCollationKeyAnalyzer(AppLuceneVersion, collator);

            var frenchAnalyzer = new FrenchAnalyzer(AppLuceneVersion);

            #region Testing the tokenizer
            Console.WriteLine("/// Testing the tokenizer");
            var tokenStream = analyzer.GetTokenStream("random", "a la maison de mon pere");

            var offsetAttribute = tokenStream.AddAttribute<IOffsetAttribute>();
            var charTermAttribute = tokenStream.AddAttribute<ICharTermAttribute>();

            tokenStream.Reset();
            while (tokenStream.IncrementToken())
            {
                int startOffset = offsetAttribute.StartOffset;
                int endOffset = offsetAttribute.EndOffset;
                var term = charTermAttribute.ToString();
                Console.WriteLine("token: {0}", term);
            }
            tokenStream.End();
            tokenStream.Dispose();

            Console.WriteLine("///");
            #endregion

            //create an index writer
            var indexConfig = new IndexWriterConfig(AppLuceneVersion, analyzer);
            
            var writer = new IndexWriter(dir, indexConfig);

            var sentences = new[] { "A", "C", "a", "F", "É", "e", "b"};

            foreach(var sentence in sentences)
            {
                var doc = new Document();
                // StringField indexes but doesn't tokenise
                doc.Add(new TextField("textfield", sentence, Field.Store.YES));
                doc.Add(new StringField("stringfield", sentence, Field.Store.YES));
                writer.AddDocument(doc);
            }

            writer.Flush(triggerMerge: false, applyAllDeletes: false);


            // search with a phrase
            var phrase = new MatchAllDocsQuery();
            
            // re-use the writer to get real-time updates
            var searcher = new IndexSearcher(writer.GetReader(applyAllDeletes: true));

            var searchField = "textfield";

            var hits = searcher.Search(phrase, 20 /* top 20 */, new Sort(new SortField(searchField, SortFieldType.STRING))).ScoreDocs;

            foreach (var hit in hits)
            {
                var foundDoc = searcher.Doc(hit.Doc);
                Console.WriteLine(foundDoc.Get("stringfield"));
            }
        }
    }
}