/// <summary>
/// Performs a full-text search match on a list of texts, using multiple Lucene query expressions.
/// </summary>
/// <param name="texts">The text to be searched/matched.</param>
/// <param name="queryExpressions">The list of Lucene query expressions.</param>
/// <param name="topN">The limit on the number of matching query expressions to return, for each text.</param>
/// <param name="cacheQuery">if set to <c>true</c> the query expressions are cached.
/// This can increase performance if the query expressions are complex and/or the number
/// of query expressions is large, and the query expressions are repeatedly used
/// (i.e. in a loop) to search/match the texts.</param>
/// <returns>
/// A list of MatchResult objects containing the status of the operation for each text.
/// </returns>
public static List<MatchResult> Match(this IList<string> texts, IList<string> queryExpressions, int? topN = null, bool cacheQuery = true)
{
using (var index = new FullTextIndex())
{
topN = topN ?? queryExpressions.Count;
var matches = new List<MatchResult>();
for (var textId = 0; textId < texts.Count; textId++)
{
// Process the current text; match it against each quey expression.
var text = texts[textId];
index.Add(text);
var matchingExpressions = new List<int>();
for (var queryId = 0; queryId < queryExpressions.Count; queryId++)
{
var query = queryExpressions[queryId];
if (index.Search(query, cacheQuery: cacheQuery).Count() > 0)
matchingExpressions.Add(queryId);
if (matchingExpressions.Count > topN)
break;
}
matches.Add(new MatchResult(matchingExpressions));
index.Clear(!cacheQuery); // Do not clear the query cache, unless we are not caching query expressions
}
return matches;
}
}
/// <summary>
/// Performs a full-text search/match on the given list of strings.
/// </summary>
/// <param name="texts">The list of texts to be searched/matched.</param>
/// <param name="queryExpression">The Lucene query expression.</param>
/// <param name="topN">The limit on the number of matching texts to return.</param>
/// <returns>
/// A MatchResult object containing the status of the operation, and if successful,
/// a list of numbers representing the index number of the text that matched the query expression.
/// </returns>
public static MatchResult Match(this IList<string> texts, string queryExpression, int? topN = null)
{
using (var index = new FullTextIndex())
{
index.Add(texts);
var docIds = index.Search(queryExpression, (topN ?? texts.Count)).ToList();
return new MatchResult(docIds);
}
}
/// <summary>
/// Performs a full-text search match on a single text string, using multiple Lucene query expressions.
/// </summary>
/// <param name="text">The text to be searched/matched.</param>
/// <param name="queryExpressions">The list of Lucene query expressions.</param>
/// <param name="topN">The limit on the number of matching query expressions to return.</param>
/// <returns>
/// A MatchResult object containing the status of the operation, and if successful,
/// a list of numbers representing the index number of the query expression that matched the text.
/// </returns>
public static MatchResult Match(this string text, IList<string> queryExpressions, int? topN = null)
{
using (var index = new FullTextIndex())
{
index.Add(text);
topN = topN ?? queryExpressions.Count;
var matchingExpressions = new List<int>();
for (var i = 0; i < queryExpressions.Count; i++)
{
var query = queryExpressions[i];
if (index.Search(query).Count() > 0)
{
matchingExpressions.Add(i);
if (matchingExpressions.Count >= topN)
break;
}
}
return new MatchResult(matchingExpressions);
}
}
