79 lines
2.6 KiB
Go
79 lines
2.6 KiB
Go
|
// Copyright (c) 2016 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 camelcase
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"unicode/utf8"
|
||
|
|
|
||
|
|
"github.com/blevesearch/bleve/analysis"
|
||
|
|
"github.com/blevesearch/bleve/registry"
|
||
|
|
)
|
||
|
|
|
||
|
|
const Name = "camelCase"
|
||
|
|
|
||
|
|
// CamelCaseFilter splits a given token into a set of tokens where each resulting token
|
||
|
|
// falls into one the following classes:
|
||
|
|
// 1) Upper case followed by lower case letters.
|
||
|
|
// Terminated by a number, an upper case letter, and a non alpha-numeric symbol.
|
||
|
|
// 2) Upper case followed by upper case letters.
|
||
|
|
// Terminated by a number, an upper case followed by a lower case letter, and a non alpha-numeric symbol.
|
||
|
|
// 3) Lower case followed by lower case letters.
|
||
|
|
// Terminated by a number, an upper case letter, and a non alpha-numeric symbol.
|
||
|
|
// 4) Number followed by numbers.
|
||
|
|
// Terminated by a letter, and a non alpha-numeric symbol.
|
||
|
|
// 5) Non alpha-numeric symbol followed by non alpha-numeric symbols.
|
||
|
|
// Terminated by a number, and a letter.
|
||
|
|
//
|
||
|
|
// It does a one-time sequential pass over an input token, from left to right.
|
||
|
|
// The scan is greedy and generates the longest substring that fits into one of the classes.
|
||
|
|
//
|
||
|
|
// See the test file for examples of classes and their parsings.
|
||
|
|
type CamelCaseFilter struct{}
|
||
|
|
|
||
|
|
func NewCamelCaseFilter() *CamelCaseFilter {
|
||
|
|
return &CamelCaseFilter{}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (f *CamelCaseFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
|
||
|
|
rv := make(analysis.TokenStream, 0, len(input))
|
||
|
|
|
||
|
|
nextPosition := 1
|
||
|
|
for _, token := range input {
|
||
|
|
runeCount := utf8.RuneCount(token.Term)
|
||
|
|
runes := bytes.Runes(token.Term)
|
||
|
|
|
||
|
|
p := NewParser(runeCount, nextPosition, token.Start)
|
||
|
|
for i := 0; i < runeCount; i++ {
|
||
|
|
if i+1 >= runeCount {
|
||
|
|
p.Push(runes[i], nil)
|
||
|
|
} else {
|
||
|
|
p.Push(runes[i], &runes[i+1])
|
||
|
|
}
|
||
|
|
}
|
||
|
|
rv = append(rv, p.FlushTokens()...)
|
||
|
|
nextPosition = p.NextPosition()
|
||
|
|
}
|
||
|
|
return rv
|
||
|
|
}
|
||
|
|
|
||
|
|
func CamelCaseFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
|
||
|
|
return NewCamelCaseFilter(), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func init() {
|
||
|
|
registry.RegisterTokenFilter(Name, CamelCaseFilterConstructor)
|
||
|
|
}
|