Class SynonymMap

There holds: If B is a synonym for A (A -> B) then A is also a synonym for B (B -> A). There does not necessary hold: A -> B, B -> C then A -> C.

Loading typically takes some 1.5 secs, so should be done only once per (server) program execution, using a singleton pattern. Once loaded, a synonym lookup via getSynonymstakes constant time O(1). A loaded default synonym map consumes about 10 MB main memory. An instance is immutable, hence thread-safe.

This implementation borrows some ideas from the Lucene Syns2Index demo that Dave Spencer originally contributed to Lucene. Dave's approach involved a persistent Lucene index which is suitable for occasional lookups or very large synonym tables, but considered unsuitable for high-frequency lookups of medium size synonym tables.

Example Usage:

 String[] words = new String[] { "hard", "woods", "forest", "wolfish", "xxxx"};
 SynonymMap map = new SynonymMap(new FileInputStream("samples/fulltext/wn_s.pl"));
 for (int i = 0; i < words.length; i++) {
     String[] synonyms = map.getSynonyms(words[i]);
     System.out.println(words[i] + ":" + java.util.Arrays.asList(synonyms).toString());
 }
 
 Example output:
 hard:[arduous, backbreaking, difficult, fermented, firmly, grueling, gruelling, heavily, heavy, intemperately, knockout, laborious, punishing, severe, severely, strong, toilsome, tough]
 woods:[forest, wood]
 forest:[afforest, timber, timberland, wood, woodland, woods]
 wolfish:[edacious, esurient, rapacious, ravening, ravenous, voracious, wolflike]
 xxxx:[]
 

Author: whoschek.AT.lbl.DOT.gov

See Also: prologdb man page Dave's synonym demo site