lucene-filter/src/index.js

Data filter for lucene queries

// Factory
const lucene = module.exports = function factory( parser ) {

  // Parser must be given
  if (!parser) {
    throw new Error('No parser given. Must be one of \'lucene\',\'lucene-queryparser\',\'lucene-query-parser\'');
  }

  // The given parser must be compatible
  if (('object' !== typeof parser) || ('function' !== typeof parser.parse)) {
    throw new Error('Incompatible parser given. Must be one of \'lucene\',\'lucene-queryparser\',\'lucene-query-parser\'');
  }

  // Returns Function(Object):Number
  function compile(query) {
    if (!query) return ()=>0;

    if ('string' === typeof query) {
      try {
        query = parser.parse(query);
      } catch(e) {
        return ()=>0;
      }
    }

    // Compile multi-query
    if (query.operator) {
      return lucene.operators[query.operator](
        compile(query.left),
        compile(query.right),
      );
    }

    // Wrapped
    if (query.left) {
      return compile(query.left);
    }


    // Ensure default boost
    query.boost = query.boost || 1;

    // Return the first detected filter
    for (const filter of lucene.filters) {
      if (filter.detect(query)) {
        return filter.compile(query);
      }
    }

    // Return no match
    return ()=>0;
  }

  // Return the data when matching
  compile.passthrough = function(parser, query) {
    let match = compile(query);
    return function(data) {
      if(match(data)) return data;
      return undefined;
    };
  };

  return compile;
};

// Add filters & operators
lucene.filters   = require('./filters');
lucene.operators = require('./operators');

// Browser exports
if (('function' === typeof define) && define.amd) {
  define(() => lucene);
} else if ('object' === typeof window) {
  window.lucene = lucene;
}