zardoz/vendor/github.com/blevesearch/bleve/analysis/tokenizer/regexp/regexp.go
2019-11-22 11:35:16 +01:00

84 lines
2.2 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 regexp
import (
"fmt"
"regexp"
"strconv"
"github.com/blevesearch/bleve/analysis"
"github.com/blevesearch/bleve/registry"
)
const Name = "regexp"
var IdeographRegexp = regexp.MustCompile(`\p{Han}|\p{Hangul}|\p{Hiragana}|\p{Katakana}`)
type RegexpTokenizer struct {
r *regexp.Regexp
}
func NewRegexpTokenizer(r *regexp.Regexp) *RegexpTokenizer {
return &RegexpTokenizer{
r: r,
}
}
func (rt *RegexpTokenizer) Tokenize(input []byte) analysis.TokenStream {
matches := rt.r.FindAllIndex(input, -1)
rv := make(analysis.TokenStream, 0, len(matches))
for i, match := range matches {
matchBytes := input[match[0]:match[1]]
if match[1]-match[0] > 0 {
token := analysis.Token{
Term: matchBytes,
Start: match[0],
End: match[1],
Position: i + 1,
Type: detectTokenType(matchBytes),
}
rv = append(rv, &token)
}
}
return rv
}
func RegexpTokenizerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.Tokenizer, error) {
rval, ok := config["regexp"].(string)
if !ok {
return nil, fmt.Errorf("must specify regexp")
}
r, err := regexp.Compile(rval)
if err != nil {
return nil, fmt.Errorf("unable to build regexp tokenizer: %v", err)
}
return NewRegexpTokenizer(r), nil
}
func init() {
registry.RegisterTokenizer(Name, RegexpTokenizerConstructor)
}
func detectTokenType(termBytes []byte) analysis.TokenType {
if IdeographRegexp.Match(termBytes) {
return analysis.Ideographic
}
_, err := strconv.ParseFloat(string(termBytes), 64)
if err == nil {
return analysis.Numeric
}
return analysis.AlphaNumeric
}