/**
* Create a CommonGramsFilter and wrap it with a CommonGramsQueryFilter
*/
public override TokenStream create(TokenStream input)
{
CommonGramsFilter commonGrams = new CommonGramsFilter(input, commonWords,
ignoreCase);
CommonGramsQueryFilter commonGramsQuery = new CommonGramsQueryFilter(
commonGrams);
return(commonGramsQuery);
}
/**
* Construct a token stream filtering the given input using a Set of common
* words to create bigrams, case-sensitive if ignoreCase is false (unless Set
* is CharArraySet). If <code>commonWords</code> is an instance of
* {@link CharArraySet} (true if <code>makeCommonSet()</code> was used to
* construct the set) it will be directly used and <code>ignoreCase</code>
* will be ignored since <code>CharArraySet</code> directly controls case
* sensitivity.
* <p/>
* If <code>commonWords</code> is not an instance of {@link CharArraySet}, a
* new CharArraySet will be constructed and <code>ignoreCase</code> will be
* used to specify the case sensitivity of that set.
*
* @param input TokenStream input in filter chain.
* @param commonWords The set of common words.
* @param ignoreCase -Ignore case when constructing bigrams for common words.
*/
public CommonGramsFilter(TokenStream input, Set commonWords, bool ignoreCase) : base(input)
{
if (commonWords is CharArraySet)
{
this.commonWords = (CharArraySet)commonWords;
}
else
{
this.commonWords = new CharArraySet(commonWords.size(), ignoreCase);
this.commonWords.addAll(commonWords);
}
init();
}
/**
* Construct a token stream filtering the given input using a Set of common
* words to create bigrams. Outputs both unigrams with position increment and
* bigrams with position increment 0 type=gram where one or both of the words
* in a potential bigram are in the set of common words .
*
* @param input TokenStream input in filter chain
* @param commonWords The set of common words.
*
*/
public CommonGramsFilter(TokenStream input, Set commonWords) : this(input, commonWords, false)
{
}
/**
* Construct a token stream filtering the given input using an Array of common
* words to create bigrams and is case-sensitive if ignoreCase is false.
*
* @param input Tokenstream in filter chain
* @param commonWords words to be used in constructing bigrams
* @param ignoreCase -Ignore case when constructing bigrams for common words.
*/
public CommonGramsFilter(TokenStream input, string[] commonWords, bool ignoreCase) : base(input)
{
this.commonWords = makeCommonSet(commonWords, ignoreCase);
init();
}
/**
* Construct a token stream filtering the given input using an Array of common
* words to create bigrams.
*
* @param input Tokenstream in filter chain
* @param commonWords words to be used in constructing bigrams
*/
public CommonGramsFilter(TokenStream input, string[] commonWords) : this(input, commonWords, false)
{
init();
}
