2014-04-17 22:55:53 +02:00
|
|
|
// 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.
|
2014-09-02 16:54:50 +02:00
|
|
|
|
2014-04-17 22:55:53 +02:00
|
|
|
package analysis
|
|
|
|
|
|
|
|
import (
|
|
|
|
"fmt"
|
2014-08-03 23:19:04 +02:00
|
|
|
"time"
|
2014-04-17 22:55:53 +02:00
|
|
|
)
|
|
|
|
|
|
|
|
type CharFilter interface {
|
|
|
|
Filter([]byte) []byte
|
|
|
|
}
|
|
|
|
|
2014-07-31 19:54:12 +02:00
|
|
|
type TokenType int
|
|
|
|
|
|
|
|
const (
|
|
|
|
AlphaNumeric TokenType = iota
|
2014-09-07 16:24:02 +02:00
|
|
|
Ideographic
|
2014-07-31 19:54:12 +02:00
|
|
|
Numeric
|
2014-08-03 23:19:04 +02:00
|
|
|
DateTime
|
2014-09-10 00:15:14 +02:00
|
|
|
Shingle
|
2014-09-11 16:39:05 +02:00
|
|
|
Single
|
|
|
|
Double
|
2014-07-31 19:54:12 +02:00
|
|
|
)
|
|
|
|
|
2015-10-09 10:54:40 +02:00
|
|
|
// Token represents one occurrence of a term at a particular location in a
|
|
|
|
// field.
|
2014-04-17 22:55:53 +02:00
|
|
|
type Token struct {
|
2015-10-09 10:54:40 +02:00
|
|
|
// Start specifies the byte offset of the beginning of the term in the
|
|
|
|
// field.
|
|
|
|
Start int `json:"start"`
|
|
|
|
|
|
|
|
// End specifies the byte offset of the end of the term in the field.
|
|
|
|
End int `json:"end"`
|
|
|
|
Term []byte `json:"term"`
|
|
|
|
|
|
|
|
// Position specifies the 1-based index of the token in the sequence of
|
|
|
|
// occurrences of its term in the field.
|
2014-09-10 00:15:14 +02:00
|
|
|
Position int `json:"position"`
|
|
|
|
Type TokenType `json:"type"`
|
|
|
|
KeyWord bool `json:"keyword"`
|
2014-04-17 22:55:53 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
func (t *Token) String() string {
|
2014-09-07 20:11:01 +02:00
|
|
|
return fmt.Sprintf("Start: %d End: %d Position: %d Token: %s Type: %d", t.Start, t.End, t.Position, string(t.Term), t.Type)
|
2014-04-17 22:55:53 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
type TokenStream []*Token
|
|
|
|
|
2015-10-27 16:51:54 +01:00
|
|
|
// A Tokenizer splits an input string into tokens, the usual behaviour being to
|
|
|
|
// map words to tokens.
|
2014-04-17 22:55:53 +02:00
|
|
|
type Tokenizer interface {
|
|
|
|
Tokenize([]byte) TokenStream
|
|
|
|
}
|
|
|
|
|
|
|
|
type TokenFilter interface {
|
|
|
|
Filter(TokenStream) TokenStream
|
|
|
|
}
|
|
|
|
|
|
|
|
type Analyzer struct {
|
|
|
|
CharFilters []CharFilter
|
|
|
|
Tokenizer Tokenizer
|
|
|
|
TokenFilters []TokenFilter
|
|
|
|
}
|
|
|
|
|
|
|
|
func (a *Analyzer) Analyze(input []byte) TokenStream {
|
|
|
|
if a.CharFilters != nil {
|
|
|
|
for _, cf := range a.CharFilters {
|
|
|
|
input = cf.Filter(input)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
tokens := a.Tokenizer.Tokenize(input)
|
|
|
|
if a.TokenFilters != nil {
|
|
|
|
for _, tf := range a.TokenFilters {
|
|
|
|
tokens = tf.Filter(tokens)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return tokens
|
|
|
|
}
|
2014-08-03 23:19:04 +02:00
|
|
|
|
2014-09-04 00:17:26 +02:00
|
|
|
var ErrInvalidDateTime = fmt.Errorf("unable to parse datetime with any of the layouts")
|
2014-08-03 23:19:04 +02:00
|
|
|
|
|
|
|
type DateTimeParser interface {
|
|
|
|
ParseDateTime(string) (time.Time, error)
|
|
|
|
}
|
2014-08-30 01:23:21 +02:00
|
|
|
|
|
|
|
type ByteArrayConverter interface {
|
|
|
|
Convert([]byte) (interface{}, error)
|
|
|
|
}
|