githaven-fork/vendor/github.com/blevesearch/bleve/search/query/wildcard.go
2017-01-25 10:43:02 +08:00

107 lines
2.6 KiB
Go

// Copyright (c) 2014 Couchbase, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package query
import (
"regexp"
"strings"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/mapping"
"github.com/blevesearch/bleve/search"
"github.com/blevesearch/bleve/search/searcher"
)
var wildcardRegexpReplacer = strings.NewReplacer(
// characters in the wildcard that must
// be escaped in the regexp
"+", `\+`,
"(", `\(`,
")", `\)`,
"^", `\^`,
"$", `\$`,
".", `\.`,
"{", `\{`,
"}", `\}`,
"[", `\[`,
"]", `\]`,
`|`, `\|`,
`\`, `\\`,
// wildcard characters
"*", ".*",
"?", ".")
type WildcardQuery struct {
Wildcard string `json:"wildcard"`
FieldVal string `json:"field,omitempty"`
BoostVal *Boost `json:"boost,omitempty"`
compiled *regexp.Regexp
}
// NewWildcardQuery creates a new Query which finds
// documents containing terms that match the
// specified wildcard. In the wildcard pattern '*'
// will match any sequence of 0 or more characters,
// and '?' will match any single character.
func NewWildcardQuery(wildcard string) *WildcardQuery {
return &WildcardQuery{
Wildcard: wildcard,
}
}
func (q *WildcardQuery) SetBoost(b float64) {
boost := Boost(b)
q.BoostVal = &boost
}
func (q *WildcardQuery) Boost() float64{
return q.BoostVal.Value()
}
func (q *WildcardQuery) SetField(f string) {
q.FieldVal = f
}
func (q *WildcardQuery) Field() string{
return q.FieldVal
}
func (q *WildcardQuery) Searcher(i index.IndexReader, m mapping.IndexMapping, explain bool) (search.Searcher, error) {
field := q.FieldVal
if q.FieldVal == "" {
field = m.DefaultSearchField()
}
if q.compiled == nil {
var err error
q.compiled, err = q.convertToRegexp()
if err != nil {
return nil, err
}
}
return searcher.NewRegexpSearcher(i, q.compiled, field, q.BoostVal.Value(), explain)
}
func (q *WildcardQuery) Validate() error {
var err error
q.compiled, err = q.convertToRegexp()
return err
}
func (q *WildcardQuery) convertToRegexp() (*regexp.Regexp, error) {
regexpString := "^" + wildcardRegexpReplacer.Replace(q.Wildcard) + "$"
return regexp.Compile(regexpString)
}