1//  Copyright (c) 2014 Couchbase, Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// 		http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package query
16
17import (
18	"strings"
19
20	"github.com/blevesearch/bleve/index"
21	"github.com/blevesearch/bleve/mapping"
22	"github.com/blevesearch/bleve/search"
23	"github.com/blevesearch/bleve/search/searcher"
24)
25
26type RegexpQuery struct {
27	Regexp   string `json:"regexp"`
28	FieldVal string `json:"field,omitempty"`
29	BoostVal *Boost `json:"boost,omitempty"`
30}
31
32// NewRegexpQuery creates a new Query which finds
33// documents containing terms that match the
34// specified regular expression.  The regexp pattern
35// SHOULD NOT include ^ or $ modifiers, the search
36// will only match entire terms even without them.
37func NewRegexpQuery(regexp string) *RegexpQuery {
38	return &RegexpQuery{
39		Regexp: regexp,
40	}
41}
42
43func (q *RegexpQuery) SetBoost(b float64) {
44	boost := Boost(b)
45	q.BoostVal = &boost
46}
47
48func (q *RegexpQuery) Boost() float64 {
49	return q.BoostVal.Value()
50}
51
52func (q *RegexpQuery) SetField(f string) {
53	q.FieldVal = f
54}
55
56func (q *RegexpQuery) Field() string {
57	return q.FieldVal
58}
59
60func (q *RegexpQuery) Searcher(i index.IndexReader, m mapping.IndexMapping, options search.SearcherOptions) (search.Searcher, error) {
61	field := q.FieldVal
62	if q.FieldVal == "" {
63		field = m.DefaultSearchField()
64	}
65
66	// require that pattern NOT be anchored to start and end of term.
67	// do not attempt to remove trailing $, its presence is not
68	// known to interfere with LiteralPrefix() the way ^ does
69	// and removing $ introduces possible ambiguities with escaped \$, \\$, etc
70	actualRegexp := q.Regexp
71	if strings.HasPrefix(actualRegexp, "^") {
72		actualRegexp = actualRegexp[1:] // remove leading ^
73	}
74
75	return searcher.NewRegexpStringSearcher(i, actualRegexp, field,
76		q.BoostVal.Value(), options)
77}
78
79func (q *RegexpQuery) Validate() error {
80	return nil // real validation delayed until searcher constructor
81}
82