/// <summary>
/// Creates <see cref="NGramTokenFilter"/> with given min and max n-grams. </summary>
/// <param name="version"> Lucene version to enable correct position increments.
/// See <see cref="NGramTokenFilter"/> for details. </param>
/// <param name="input"> <see cref="TokenStream"/> holding the input to be tokenized </param>
/// <param name="minGram"> the smallest n-gram to generate </param>
/// <param name="maxGram"> the largest n-gram to generate </param>
public NGramTokenFilter(LuceneVersion version, TokenStream input, int minGram, int maxGram)
: base(new CodepointCountFilter(version, input, minGram, int.MaxValue))
{
this.version = version;
this.charUtils = version.OnOrAfter(
#pragma warning disable 612, 618
LuceneVersion.LUCENE_44) ?
#pragma warning restore 612, 618
CharacterUtils.GetInstance(version) : CharacterUtils.GetJava4Instance(version);
if (minGram < 1)
{
throw new ArgumentException("minGram must be greater than zero");
}
if (minGram > maxGram)
{
throw new ArgumentException("minGram must not be greater than maxGram");
}
this.minGram = minGram;
this.maxGram = maxGram;
#pragma warning disable 612, 618
if (version.OnOrAfter(LuceneVersion.LUCENE_44))
#pragma warning restore 612, 618
{
posIncAtt = AddAttribute <IPositionIncrementAttribute>();
posLenAtt = AddAttribute <IPositionLengthAttribute>();
}
else
{
posIncAtt = new PositionIncrementAttributeAnonymousInnerClassHelper();
posLenAtt = new PositionLengthAttributeAnonymousInnerClassHelper();
}
termAtt = AddAttribute <ICharTermAttribute>();
offsetAtt = AddAttribute <IOffsetAttribute>();
}
private void Init(LuceneVersion version, int minGram, int maxGram, bool edgesOnly)
{
#pragma warning disable 612, 618
if (!version.OnOrAfter(LuceneVersion.LUCENE_44))
#pragma warning restore 612, 618
{
throw new ArgumentException("This class only works with Lucene 4.4+. To emulate the old (broken) behavior of NGramTokenizer, use Lucene43NGramTokenizer/Lucene43EdgeNGramTokenizer");
}
#pragma warning disable 612, 618
charUtils = version.OnOrAfter(LuceneVersion.LUCENE_44) ?
#pragma warning restore 612, 618
CharacterUtils.GetInstance(version) : CharacterUtils.GetJava4Instance(version);
if (minGram < 1)
{
throw new ArgumentException("minGram must be greater than zero");
}
if (minGram > maxGram)
{
throw new ArgumentException("minGram must not be greater than maxGram");
}
termAtt = AddAttribute <ICharTermAttribute>();
posIncAtt = AddAttribute <IPositionIncrementAttribute>();
posLenAtt = AddAttribute <IPositionLengthAttribute>();
offsetAtt = AddAttribute <IOffsetAttribute>();
this.minGram = minGram;
this.maxGram = maxGram;
this.edgesOnly = edgesOnly;
charBuffer = CharacterUtils.NewCharacterBuffer(2 * maxGram + 1024); // 2 * maxGram in case all code points require 2 chars and + 1024 for buffering to not keep polling the Reader
buffer = new int[charBuffer.Buffer.Length];
// Make the term att large enough
termAtt.ResizeBuffer(2 * maxGram);
}
public EdgeNGramTokenFilter(LuceneVersion version, TokenStream input, Side side, int minGram, int maxGram)
: base(input)
{
//if (version == null)
//{
// throw new ArgumentException("version must not be null");
//}
if (version.OnOrAfter(LuceneVersion.LUCENE_44) && side == Side.BACK)
{
throw new ArgumentException("Side.BACK is not supported anymore as of Lucene 4.4, use ReverseStringFilter up-front and afterward");
}
if (!Enum.IsDefined(typeof(Side), side))
{
throw new ArgumentException("sideLabel must be either front or back");
}
if (minGram < 1)
{
throw new ArgumentException("minGram must be greater than zero");
}
if (minGram > maxGram)
{
throw new ArgumentException("minGram must not be greater than maxGram");
}
this.version = version;
this.charUtils = version.OnOrAfter(LuceneVersion.LUCENE_44) ? CharacterUtils.GetInstance(version) : CharacterUtils.GetJava4Instance(version);
this.minGram = minGram;
this.maxGram = maxGram;
this.side = side;
this.termAtt = AddAttribute <ICharTermAttribute>();
this.offsetAtt = AddAttribute <IOffsetAttribute>();
this.posIncrAtt = AddAttribute <IPositionIncrementAttribute>();
this.posLenAtt = AddAttribute <IPositionLengthAttribute>();
}
public EdgeNGramTokenFilter(LuceneVersion version, TokenStream input, Side side, int minGram, int maxGram)
: base(input)
{
// LUCENENET specific - version cannot be null because it is a value type.
if (version.OnOrAfter(LuceneVersion.LUCENE_44) && side == Side.BACK)
{
throw new ArgumentException("Side.BACK is not supported anymore as of Lucene 4.4, use ReverseStringFilter up-front and afterward");
}
if (!side.IsDefined())
{
throw new ArgumentOutOfRangeException(nameof(side), "sideLabel must be either front or back"); // LUCENENET specific - changed from IllegalArgumentException to ArgumentOutOfRangeException (.NET convention)
}
if (minGram < 1)
{
throw new ArgumentOutOfRangeException(nameof(minGram), "minGram must be greater than zero"); // LUCENENET specific - changed from IllegalArgumentException to ArgumentOutOfRangeException (.NET convention)
}
if (minGram > maxGram)
{
throw new ArgumentException("minGram must not be greater than maxGram");
}
this.version = version;
this.charUtils = version.OnOrAfter(LuceneVersion.LUCENE_44) ? CharacterUtils.GetInstance(version) : CharacterUtils.GetJava4Instance(version);
this.minGram = minGram;
this.maxGram = maxGram;
this.side = side;
this.termAtt = AddAttribute <ICharTermAttribute>();
this.offsetAtt = AddAttribute <IOffsetAttribute>();
this.posIncrAtt = AddAttribute <IPositionIncrementAttribute>();
this.posLenAtt = AddAttribute <IPositionLengthAttribute>();
}
