Suggestions and Spellchecking

[nzdev]

Adds support for Suggestions for search text.

Adds ISuggester to IIndex for running suggestion queries, includes Lucene implementation.
Added suggester to Demo site.
Added documentation
Added tests

Registering Suggesters

On the index to register the Suggesters, create a SuggesterDefinitionCollection and set it on IndexOptions.SuggesterDefinitions. Only FullText fields can be source fields for suggesters.

Example

 var suggesters = new SuggesterDefinitionCollection();
          suggesters.AddOrUpdate(new AnalyzingInfixSuggesterDefinition(ExamineLuceneSuggesterNames.AnalyzingInfixSuggester, new string[] { "nodeName" }, new RAMSuggesterDirectoryFactory()));
            suggesters.AddOrUpdate(new AnalyzingSuggesterDefinition(ExamineLuceneSuggesterNames.AnalyzingSuggester, new string[] { "nodeName" }));
            suggesters.AddOrUpdate(new DirectSpellCheckerDefinition(ExamineLuceneSuggesterNames.DirectSpellChecker, new string[] { "nodeName" }));
            suggesters.AddOrUpdate(new LevensteinDistanceSuggesterDefinition(ExamineLuceneSuggesterNames.DirectSpellChecker_LevensteinDistance, new string[] { "nodeName" }));
            suggesters.AddOrUpdate(new JaroWinklerDistanceDefinition(ExamineLuceneSuggesterNames.DirectSpellChecker_JaroWinklerDistance, new string[] { "nodeName" }));
            suggesters.AddOrUpdate(new NGramDistanceSuggesterDefinition(ExamineLuceneSuggesterNames.DirectSpellChecker_NGramDistance, new string[] { "nodeName" }));
            suggesters.AddOrUpdate(new FuzzySuggesterDefinition(ExamineLuceneSuggesterNames.FuzzySuggester, new string[] { "nodeName" }));

Suggester API

var suggester = index.Suggester;
var query = suggester.CreateSuggestionQuery();
var results = query.Execute("Sam", new SuggestionOptions(5,ExamineLuceneSuggesterNames.AnalyzingSuggester));

This code will run a suggestion for the input text "Sam", returning up to 5 suggestions.

Lucene Suggesters

To generate suggestions for input text, retreive the ISuggester from the index IIndex.Suggester.

Analyzing Infix Suggester

var suggester = index.Suggester;
var query = suggester.CreateSuggestionQuery();
var results = query.Execute("Sam", new LuceneSuggestionOptions(5, ExamineLuceneSuggesterNames.AnalyzingInfixSuggester));

This code will run a suggestion for the input text "Sam", returning up to 5 suggestions, and will highlight the result text which matches the input text..

Analyzing Suggester

var suggester = index.Suggester;
var query = suggester.CreateSuggestionQuery();
var results = query.Execute("Sam", new LuceneSuggestionOptions(5, ExamineLuceneSuggesterNames.AnalyzingSuggester));

This code will run a suggestion for the input text "Sam", returning up to 5 suggestions.

Fuzzy Suggester

var suggester = index.Suggester;
var query = suggester.CreateSuggestionQuery();
var results = query.Execute("Sam", new LuceneSuggestionOptions(5, ExamineLuceneSuggesterNames.FuzzySuggester));

This code will run a Fuzzy suggestion for the input text "Sam", returning up to 5 suggestions.

Direct SpellChecker Suggester

var suggester = index.Suggester;
var query = suggester.CreateSuggestionQuery();
var results = query.Execute("Sam", new LuceneSuggestionOptions(5, ExamineLuceneSuggesterNames.DirectSpellChecker));

This code will run a spellchecker suggestion for the input text "Sam" returning up to 5 suggestions.

[nzdev]

I think this is in a good spot now that it can be extended and there is support for suggestions in the demoweb.

[nikcio]

@nzdev I've left some comments - It's mostly about XML comments and I didn't mark everything I think you get the gist. You should also consider if this feature should go into Examine v3 or v4. I can see some areas where this could have binary breaking changes and therefore this, should properly be in v4. And then you could rebase and get nullable and XML warnings.

[nzdev]

Updated for V4. Docs added.