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bleve/analysis/token/length/length.go
2016-10-02 10:13:14 -04:00

78 lines
1.7 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 length
import (
"fmt"
"unicode/utf8"
"github.com/blevesearch/bleve/analysis"
"github.com/blevesearch/bleve/registry"
)
const Name = "length"
type LengthFilter struct {
min int
max int
}
func NewLengthFilter(min, max int) *LengthFilter {
return &LengthFilter{
min: min,
max: max,
}
}
func (f *LengthFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
rv := make(analysis.TokenStream, 0, len(input))
for _, token := range input {
wordLen := utf8.RuneCount(token.Term)
if f.min > 0 && f.min > wordLen {
continue
}
if f.max > 0 && f.max < wordLen {
continue
}
rv = append(rv, token)
}
return rv
}
func LengthFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
min := 0
max := 0
minVal, ok := config["min"].(float64)
if ok {
min = int(minVal)
}
maxVal, ok := config["max"].(float64)
if ok {
max = int(maxVal)
}
if min == max && max == 0 {
return nil, fmt.Errorf("either min or max must be non-zero")
}
return NewLengthFilter(min, max), nil
}
func init() {
registry.RegisterTokenFilter(Name, LengthFilterConstructor)
}