This TokenFilter create n-grams from the beginning edge or ending edge of a input token.
As of Lucene 4.4, this filter does not support Side#BACK (you can use ReverseStringFilter up-front and afterward to get the same behavior), handles supplementary characters correctly and does not update offsets anymore.
public virtual void TestFilterPositions() { TokenStream ts = new MockTokenizer(new StringReader("abcde vwxyz"), MockTokenizer.WHITESPACE, false); EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, ts, EdgeNGramTokenFilter.Side.FRONT, 1, 3); AssertTokenStreamContents(tokenizer, new string[] { "a", "ab", "abc", "v", "vw", "vwx" }, new int[] { 0, 0, 0, 6, 6, 6 }, new int[] { 5, 5, 5, 11, 11, 11 }, null, new int[] { 1, 0, 0, 1, 0, 0 }, null, null, false); }
public virtual void TestFrontUnigram() { #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 1, 1); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[] { "a" }, new int[] { 0 }, new int[] { 5 }); }
public virtual void TestBackRangeOfNgrams() { #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(LuceneVersion.LUCENE_43, input, EdgeNGramTokenFilter.Side.BACK, 1, 3); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[] { "e", "de", "cde" }, new int[] { 4, 3, 2 }, new int[] { 5, 5, 5 }, null, null, null, null, false); }
public virtual void TestBackUnigram() { #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(LuceneVersion.LUCENE_43, input, EdgeNGramTokenFilter.Side.BACK, 1, 1); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[] { "e" }, new int[] { 4 }, new int[] { 5 }); }
public virtual void TestOversizedNgrams() { #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 6, 6); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[0], new int[0], new int[0]); }
public virtual void TestSmallTokenInStream() { input = new MockTokenizer(new StringReader("abc de fgh"), MockTokenizer.WHITESPACE, false); EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 3, 3); AssertTokenStreamContents(tokenizer, new string[] { "abc", "fgh" }, new int[] { 0, 7 }, new int[] { 3, 10 }); }
public override TokenStreamComponents CreateComponents(string fieldName, TextReader reader) { Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.WHITESPACE, false); TokenFilter filters = new ASCIIFoldingFilter(tokenizer); filters = new EdgeNGramTokenFilter(LuceneVersion.LUCENE_43, filters, EdgeNGramTokenFilter.Side.FRONT, 2, 15); return(new TokenStreamComponents(tokenizer, filters)); }
public virtual void TestFilterPositions() { TokenStream ts = new MockTokenizer(new StringReader("abcde vwxyz"), MockTokenizer.WHITESPACE, false); #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, ts, EdgeNGramTokenFilter.Side.FRONT, 1, 3); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[] { "a", "ab", "abc", "v", "vw", "vwx" }, new int[] { 0, 0, 0, 6, 6, 6 }, new int[] { 5, 5, 5, 11, 11, 11 }, null, new int[] { 1, 0, 0, 1, 0, 0 }, null, null, false); }
public virtual void TestGraphs() { TokenStream tk = new LetterTokenizer(TEST_VERSION_CURRENT, new StringReader("abc d efgh ij klmno p q")); tk = new ShingleFilter(tk); tk = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tk, 7, 10); AssertTokenStreamContents(tk, new string[] { "efgh ij", "ij klmn", "ij klmno", "klmno p" }, new int[] { 6, 11, 11, 14 }, new int[] { 13, 19, 19, 21 }, new int[] { 3, 1, 0, 1 }, new int[] { 2, 2, 2, 2 }, 23); }
public virtual void TestReset() { WhitespaceTokenizer tokenizer = new WhitespaceTokenizer(TEST_VERSION_CURRENT, new StringReader("abcde")); EdgeNGramTokenFilter filter = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tokenizer, EdgeNGramTokenFilter.Side.FRONT, 1, 3); AssertTokenStreamContents(filter, new string[] { "a", "ab", "abc" }, new int[] { 0, 0, 0 }, new int[] { 5, 5, 5 }); tokenizer.Reader = new StringReader("abcde"); AssertTokenStreamContents(filter, new string[] { "a", "ab", "abc" }, new int[] { 0, 0, 0 }, new int[] { 5, 5, 5 }); }
public virtual void TestFirstTokenPositionIncrement() { TokenStream ts = new MockTokenizer(new StringReader("a abc"), MockTokenizer.WHITESPACE, false); ts = new PositionFilter(ts); // All but first token will get 0 position increment EdgeNGramTokenFilter filter = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, ts, EdgeNGramTokenFilter.Side.FRONT, 2, 3); // The first token "a" will not be output, since it's smaller than the mingram size of 2. // The second token on input to EdgeNGramTokenFilter will have position increment of 0, // which should be increased to 1, since this is the first output token in the stream. AssertTokenStreamContents(filter, new string[] { "ab", "abc" }, new int[] { 2, 2 }, new int[] { 5, 5 }, new int[] { 1, 0 }); }
public virtual void TestSupplementaryCharacters() { string s = TestUtil.RandomUnicodeString(Random(), 10); int codePointCount = Character.CodePointCount(s, 0, s.Length); int minGram = TestUtil.NextInt(Random(), 1, 3); int maxGram = TestUtil.NextInt(Random(), minGram, 10); TokenStream tk = new KeywordTokenizer(new StringReader(s)); tk = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tk, minGram, maxGram); ICharTermAttribute termAtt = tk.AddAttribute <ICharTermAttribute>(); IOffsetAttribute offsetAtt = tk.AddAttribute <IOffsetAttribute>(); tk.Reset(); for (int i = minGram; i <= Math.Min(codePointCount, maxGram); ++i) { assertTrue(tk.IncrementToken()); assertEquals(0, offsetAtt.StartOffset()); assertEquals(s.Length, offsetAtt.EndOffset()); int end = Character.OffsetByCodePoints(s, 0, i); assertEquals(s.Substring(0, end), termAtt.ToString()); } assertFalse(tk.IncrementToken()); }
public virtual void TestSmallTokenInStream() { input = new MockTokenizer(new StringReader("abc de fgh"), MockTokenizer.WHITESPACE, false); #pragma warning disable 612, 618 EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 3, 3); #pragma warning restore 612, 618 AssertTokenStreamContents(tokenizer, new string[] { "abc", "fgh" }, new int[] { 0, 7 }, new int[] { 3, 10 }); }
public virtual void TestSupplementaryCharacters() { string s = TestUtil.RandomUnicodeString(Random(), 10); int codePointCount = Character.CodePointCount(s, 0, s.Length); int minGram = TestUtil.NextInt(Random(), 1, 3); int maxGram = TestUtil.NextInt(Random(), minGram, 10); TokenStream tk = new KeywordTokenizer(new StringReader(s)); tk = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tk, minGram, maxGram); ICharTermAttribute termAtt = tk.AddAttribute<ICharTermAttribute>(); IOffsetAttribute offsetAtt = tk.AddAttribute<IOffsetAttribute>(); tk.Reset(); for (int i = minGram; i <= Math.Min(codePointCount, maxGram); ++i) { assertTrue(tk.IncrementToken()); assertEquals(0, offsetAtt.StartOffset()); assertEquals(s.Length, offsetAtt.EndOffset()); int end = Character.OffsetByCodePoints(s, 0, i); assertEquals(s.Substring(0, end), termAtt.ToString()); } assertFalse(tk.IncrementToken()); }
public override TokenStreamComponents CreateComponents(string fieldName, TextReader reader) { Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.WHITESPACE, false); TokenFilter filters = new ASCIIFoldingFilter(tokenizer); #pragma warning disable 612, 618 filters = new EdgeNGramTokenFilter(LuceneVersion.LUCENE_43, filters, EdgeNGramTokenFilter.Side.FRONT, 2, 15); #pragma warning restore 612, 618 return new TokenStreamComponents(tokenizer, filters); }
public virtual void TestBackUnigram() { EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(LuceneVersion.LUCENE_43, input, EdgeNGramTokenFilter.Side.BACK, 1, 1); AssertTokenStreamContents(tokenizer, new string[] { "e" }, new int[] { 4 }, new int[] { 5 }); }
public virtual void TestFrontUnigram() { EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 1, 1); AssertTokenStreamContents(tokenizer, new string[] { "a" }, new int[] { 0 }, new int[] { 5 }); }
public virtual void TestFirstTokenPositionIncrement() { TokenStream ts = new MockTokenizer(new StringReader("a abc"), MockTokenizer.WHITESPACE, false); ts = new PositionFilter(ts); // All but first token will get 0 position increment #pragma warning disable 612, 618 EdgeNGramTokenFilter filter = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, ts, EdgeNGramTokenFilter.Side.FRONT, 2, 3); #pragma warning restore 612, 618 // The first token "a" will not be output, since it's smaller than the mingram size of 2. // The second token on input to EdgeNGramTokenFilter will have position increment of 0, // which should be increased to 1, since this is the first output token in the stream. AssertTokenStreamContents(filter, new string[] { "ab", "abc" }, new int[] { 2, 2 }, new int[] { 5, 5 }, new int[] { 1, 0 }); }
public virtual void TestOversizedNgrams() { EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 6, 6); AssertTokenStreamContents(tokenizer, new string[0], new int[0], new int[0]); }
public virtual void TestFrontRangeOfNgrams() { EdgeNGramTokenFilter tokenizer = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, input, EdgeNGramTokenFilter.Side.FRONT, 1, 3); AssertTokenStreamContents(tokenizer, new string[] { "a", "ab", "abc" }, new int[] { 0, 0, 0 }, new int[] { 5, 5, 5 }); }
public virtual void TestReset() { WhitespaceTokenizer tokenizer = new WhitespaceTokenizer(TEST_VERSION_CURRENT, new StringReader("abcde")); #pragma warning disable 612, 618 EdgeNGramTokenFilter filter = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tokenizer, EdgeNGramTokenFilter.Side.FRONT, 1, 3); #pragma warning restore 612, 618 AssertTokenStreamContents(filter, new string[] { "a", "ab", "abc" }, new int[] { 0, 0, 0 }, new int[] { 5, 5, 5 }); tokenizer.Reader = new StringReader("abcde"); AssertTokenStreamContents(filter, new string[] { "a", "ab", "abc" }, new int[] { 0, 0, 0 }, new int[] { 5, 5, 5 }); }