public interface: PositionIncrementAttribute
All Implemented Interfaces:
All Known Implementing Classes:
The positionIncrement determines the position of this token
relative to the previous Token in a TokenStream, used in phrase
The default value is one.
Some common uses for this are:
- Set it to zero to put multiple terms in the same position. This is
useful if, e.g., a word has multiple stems. Searches for phrases
including either stem will match. In this case, all but the first stem's
increment should be set to zero: the increment of the first instance
should be one. Repeating a token with an increment of zero can also be
used to boost the scores of matches on that token.
- Set it to values greater than one to inhibit exact phrase matches.
If, for example, one does not want phrases to match across removed stop
words, then one could build a stop word filter that removes stop words and
also sets the increment to the number of stop words removed before each
non-stop word. Then exact phrase queries will only match when the terms
occur with no intervening stop words.