Literal Substring Implementation Details
The same as the substring search but with special characters enabled.
Algorithm:
The Literal Substring search has the following characteristics:
- This search is case in-sensitive.
- It only searches on the literal property value and the literal reverse property value.
- A leading and trailing wild card is added to the token in the search text.
- The literal property part (without the wild cards) of the query is boosted by 50. This gives a literal match priority.
Parsing is done with the following analyzers:
literal_propertyValue - Uses our custom literal analyzer. This literal analyzer uses Lucene's WhitespaceTokenizer with Lucene's LowerCaseFilter.
propertyValue - Uses our custom standard analyzer that has no stop words.
Example of use:
The following examples are based on the Automobiles coding scheme.
Example 1:
Search string: a^s
Lucene query: +literal_propertyValue:*a^s* literal_propertyValue:a^s^50.0
Result: 1 result
- entity code: SpecialCharactersConcept
- entity description: Concept containing special characters
Example 2:
Search string: a^s sp*cial
Lucene query: +spanNear([mask(spanWildcardQuery(literal_reverse_propertyValue:s^a*)) as propertyValue, mask(spanWildcardQuery(literal_propertyValue:sp*cial*)) as propertyValue], 0, true) ((+literal_propertyValue:a^s +literal_propertyValue:sp*cial)^50.0)
Result: 1 result
- entity code: SpecialCharactersConcept
- entity description: Concept containing special characters
Associated JUnits:
Junits can be found here: https://github.com/lexevs/lexevs/blob/master/lbTest/src/test/java/org/LexGrid/LexBIG/Impl/function/query/lucene/searchAlgorithms/TestLiteralSubString.java
