using System;

using Lifti;

using Lifti.Querying;

using Lifti.Querying.QueryParts;

using Lifti.Tokenization;

using System.Threading.Tasks;

using System.Collections.Generic;

public class Program

{

    public static async Task Main()

    {

        var index = new FullTextIndexBuilder<string>()

                        .WithDefaultTokenization(o => o.CaseInsensitive())

                        .WithQueryParser(new CustomWildcardQueryParser())

                        .Build();

​

        index.BeginBatchChange();

        await index.AddAsync("QueryPart", "QueryPart");

        await index.AddAsync("ExactWordQueryPart", "ExactWordQueryPart");

        await index.AddAsync("FuzzyMatchQueryPart", "FuzzyMatchQueryPart");

        await index.AddAsync("FullTextIndex", "FullTextIndex");

        await index.AddAsync("IFullTextIndex", "IFullTextIndex");

        await index.CommitBatchChangeAsync();

​

        foreach (var item in index.Search("fti"))

        {

            Console.WriteLine(item.Key);

        }

    }

}

​

public class CustomWildcardQueryParser : IQueryParser

{

    public IQuery Parse(IIndexedFieldLookup fieldLookup, string queryText, ITokenizer tokenizer)

    {

        // Use the default tokenizer to normalize the text so it's the same as in the index

        queryText = tokenizer.Normalize(queryText);

​

        var queryFragments = new List<WildcardQueryFragment>();

​

        // Add the leading multi-character match

        queryFragments.Add(WildcardQueryFragment.MultiCharacter);

​

        // Add each character in the query text, with a trailing multi-character match

        foreach (var letter in queryText)

        {

            queryFragments.Add(WildcardQueryFragment.CreateText(letter.ToString()));

            queryFragments.Add(WildcardQueryFragment.MultiCharacter);

        }

​

        // Compose the final query

        return new Query(new WildcardQueryPart(queryFragments));

    }

}