forked from blevesearch/bleve
-
Notifications
You must be signed in to change notification settings - Fork 0
/
dict.go
141 lines (125 loc) · 3.9 KB
/
dict.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
// 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 compound
import (
"bytes"
"fmt"
"unicode/utf8"
"github.com/qri-io/bleve/analysis"
"github.com/qri-io/bleve/registry"
)
const Name = "dict_compound"
const defaultMinWordSize = 5
const defaultMinSubWordSize = 2
const defaultMaxSubWordSize = 15
const defaultOnlyLongestMatch = false
type DictionaryCompoundFilter struct {
dict analysis.TokenMap
minWordSize int
minSubWordSize int
maxSubWordSize int
onlyLongestMatch bool
}
func NewDictionaryCompoundFilter(dict analysis.TokenMap, minWordSize, minSubWordSize, maxSubWordSize int, onlyLongestMatch bool) *DictionaryCompoundFilter {
return &DictionaryCompoundFilter{
dict: dict,
minWordSize: minWordSize,
minSubWordSize: minSubWordSize,
maxSubWordSize: maxSubWordSize,
onlyLongestMatch: onlyLongestMatch,
}
}
func (f *DictionaryCompoundFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
rv := make(analysis.TokenStream, 0, len(input))
for _, token := range input {
rv = append(rv, token)
tokenLen := utf8.RuneCount(token.Term)
if tokenLen >= f.minWordSize {
newtokens := f.decompose(token)
for _, newtoken := range newtokens {
rv = append(rv, newtoken)
}
}
}
return rv
}
func (f *DictionaryCompoundFilter) decompose(token *analysis.Token) []*analysis.Token {
runes := bytes.Runes(token.Term)
rv := make([]*analysis.Token, 0)
rlen := len(runes)
for i := 0; i <= (rlen - f.minSubWordSize); i++ {
var longestMatchToken *analysis.Token
for j := f.minSubWordSize; j <= f.maxSubWordSize; j++ {
if i+j > rlen {
break
}
_, inDict := f.dict[string(runes[i:i+j])]
if inDict {
newtoken := analysis.Token{
Term: []byte(string(runes[i : i+j])),
Position: token.Position,
Start: token.Start + i,
End: token.Start + i + j,
Type: token.Type,
KeyWord: token.KeyWord,
}
if f.onlyLongestMatch {
if longestMatchToken == nil || utf8.RuneCount(longestMatchToken.Term) < j {
longestMatchToken = &newtoken
}
} else {
rv = append(rv, &newtoken)
}
}
}
if f.onlyLongestMatch && longestMatchToken != nil {
rv = append(rv, longestMatchToken)
}
}
return rv
}
func DictionaryCompoundFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
minWordSize := defaultMinWordSize
minSubWordSize := defaultMinSubWordSize
maxSubWordSize := defaultMaxSubWordSize
onlyLongestMatch := defaultOnlyLongestMatch
minVal, ok := config["min_word_size"].(float64)
if ok {
minWordSize = int(minVal)
}
minSubVal, ok := config["min_subword_size"].(float64)
if ok {
minSubWordSize = int(minSubVal)
}
maxSubVal, ok := config["max_subword_size"].(float64)
if ok {
maxSubWordSize = int(maxSubVal)
}
onlyVal, ok := config["only_longest_match"].(bool)
if ok {
onlyLongestMatch = onlyVal
}
dictTokenMapName, ok := config["dict_token_map"].(string)
if !ok {
return nil, fmt.Errorf("must specify dict_token_map")
}
dictTokenMap, err := cache.TokenMapNamed(dictTokenMapName)
if err != nil {
return nil, fmt.Errorf("error building dict compound words filter: %v", err)
}
return NewDictionaryCompoundFilter(dictTokenMap, minWordSize, minSubWordSize, maxSubWordSize, onlyLongestMatch), nil
}
func init() {
registry.RegisterTokenFilter(Name, DictionaryCompoundFilterConstructor)
}