test_parser
 
  test_parser
 
 
  test_parser> is an example of a custom parser for full-text
  search.  It doesn't do anything especially useful, but can serve as
  a starting point for developing your own parser.
 
 
  test_parser> recognizes words separated by white space,
  and returns just two token types:
mydb=# SELECT * FROM ts_token_type('testparser');
 tokid | alias |  description
-------+-------+---------------
     3 | word  | Word
    12 | blank | Space symbols
(2 rows)
  These token numbers have been chosen to be compatible with the default
  parser's numbering.  This allows us to use its headline()>
  function, thus keeping the example simple.
 
 
  Usage
  
   Running the installation script creates a text search parser
   testparser>.  It has no user-configurable parameters.
  
  
   You can test the parser with, for example,
mydb=# SELECT * FROM ts_parse('testparser', 'That''s my first own parser');
 tokid | token
-------+--------
     3 | That's
    12 |
     3 | my
    12 |
     3 | first
    12 |
     3 | own
    12 |
     3 | parser
  
  
   Real-world use requires setting up a text search configuration
   that uses the parser.  For example,
mydb=# CREATE TEXT SEARCH CONFIGURATION testcfg ( PARSER = testparser );
CREATE TEXT SEARCH CONFIGURATION
mydb=# ALTER TEXT SEARCH CONFIGURATION testcfg
mydb-#   ADD MAPPING FOR word WITH english_stem;
ALTER TEXT SEARCH CONFIGURATION
mydb=#  SELECT to_tsvector('testcfg', 'That''s my first own parser');
          to_tsvector
-------------------------------
 'that':1 'first':3 'parser':5
(1 row)
mydb=# SELECT ts_headline('testcfg', 'Supernovae stars are the brightest phenomena in galaxies',
mydb(#                    to_tsquery('testcfg', 'star'));
                           ts_headline
-----------------------------------------------------------------
 Supernovae <b>stars</b> are the brightest phenomena in galaxies
(1 row)