public final class ScandinavianFoldingFilter extends TokenFilter
It's a semantically more destructive solution than
can in addition help with matching raksmorgas as räksmörgås.
blåbærsyltetøj == blåbärsyltetöj == blaabaarsyltetoej == blabarsyltetoj räksmörgås == ræksmørgås == ræksmörgaos == raeksmoergaas == raksmorgas
Background: Swedish åäö are in fact the same letters as Norwegian and Danish åæø and thus interchangeable when used between these languages. They are however folded differently when people type them on a keyboard lacking these characters.
In that situation almost all Swedish people use a, a, o instead of å, ä, ö.
Norwegians and Danes on the other hand usually type aa, ae and oe instead of å, æ and ø. Some do however use a, a, o, oo, ao and sometimes permutations of everything above.
This filter solves that mismatch problem, but might also cause new.
|Constructor and Description|
|Modifier and Type||Method and Description|
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
public boolean incrementToken() throws IOException
IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate
AttributeImpls with the attributes of the next token.
The producer must make no assumptions about the attributes after the method
has been returned: the caller may arbitrarily change it. If the producer
needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState() to create a copy of the current attribute state.
This method is called for every token of a document, so an efficient
implementation is crucial for good performance. To avoid calls to
references to all
AttributeImpls that this stream uses should be
retrieved during instantiation.
To ensure that filters and consumers know which attributes are available,
the attributes must be added during instantiation. Filters and consumers
are not required to check for availability of attributes in