func NewFuzzySearcher(indexReader index.IndexReader, term string, prefix, fuzziness int, field string, boost float64, explain bool) (*FuzzySearcher, error) { prefixTerm := "" for i, r := range term { if i < prefix { prefixTerm += string(r) } } // find the terms with this prefix var fieldDict index.FieldDict var err error if len(prefixTerm) > 0 { fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm)) } else { fieldDict, err = indexReader.FieldDict(field) } // enumerate terms and check levenshtein distance candidateTerms := make([]string, 0) tfd, err := fieldDict.Next() for err == nil && tfd != nil { ld, exceeded := search.LevenshteinDistanceMax(&term, &tfd.Term, fuzziness) if !exceeded && ld <= fuzziness { candidateTerms = append(candidateTerms, tfd.Term) } tfd, err = fieldDict.Next() } if err != nil { return nil, err } // enumerate all the terms in the range qsearchers := make([]search.Searcher, 0, 25) for _, cterm := range candidateTerms { qsearcher, err := NewTermSearcher(indexReader, cterm, field, 1.0, explain) if err != nil { return nil, err } qsearchers = append(qsearchers, qsearcher) } // build disjunction searcher of these ranges searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain) if err != nil { return nil, err } return &FuzzySearcher{ indexReader: indexReader, term: term, prefix: prefix, fuzziness: fuzziness, field: field, explain: explain, searcher: searcher, }, nil }
func NewRegexpSearcher(indexReader index.IndexReader, pattern *regexp.Regexp, field string, boost float64, explain bool) (*RegexpSearcher, error) { prefixTerm, complete := pattern.LiteralPrefix() candidateTerms := make([]string, 0) if complete { // there is no pattern candidateTerms = append(candidateTerms, prefixTerm) } else { var fieldDict index.FieldDict var err error if len(prefixTerm) > 0 { fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm)) } else { fieldDict, err = indexReader.FieldDict(field) } // enumerate the terms and check against regexp tfd, err := fieldDict.Next() for err == nil && tfd != nil { if pattern.MatchString(tfd.Term) { candidateTerms = append(candidateTerms, tfd.Term) } tfd, err = fieldDict.Next() } if err != nil { return nil, err } } // enumerate all the terms in the range qsearchers := make([]search.Searcher, 0, 25) for _, cterm := range candidateTerms { qsearcher, err := NewTermSearcher(indexReader, cterm, field, 1.0, explain) if err != nil { return nil, err } qsearchers = append(qsearchers, qsearcher) } // build disjunction searcher of these ranges searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain) if err != nil { return nil, err } return &RegexpSearcher{ indexReader: indexReader, pattern: pattern, field: field, explain: explain, searcher: searcher, }, nil }