90 lines
2.4 KiB
Go
90 lines
2.4 KiB
Go
// Copyright (c) 2016 Couchbase, Inc.
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
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// except in compliance with the License. You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed under the
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// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
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// either express or implied. See the License for the specific language governing permissions
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// and limitations under the License.
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package camelcase_filter
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import (
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"github.com/blevesearch/bleve/analysis"
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)
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func buildTokenFromTerm(buffer []rune) *analysis.Token {
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return &analysis.Token{
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Term: analysis.BuildTermFromRunes(buffer),
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}
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}
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// Parser accepts a symbol and passes it to the current state (representing a class).
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// The state can accept it (and accumulate it). Otherwise, the parser creates a new state that
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// starts with the pushed symbol.
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//
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// Parser accumulates a new resulting token every time it switches state.
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// Use FlushTokens() to get the results after the last symbol was pushed.
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type Parser struct {
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bufferLen int
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buffer []rune
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current State
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tokens []*analysis.Token
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}
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func NewParser(len int) *Parser {
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return &Parser{
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bufferLen: len,
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buffer: make([]rune, 0, len),
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tokens: make([]*analysis.Token, 0, len),
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}
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}
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func (p *Parser) Push(sym rune, peek *rune) {
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if p.current == nil {
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// the start of parsing
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p.current = p.NewState(sym)
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p.buffer = append(p.buffer, sym)
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} else if p.current.Member(sym, peek) {
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// same state, just accumulate
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p.buffer = append(p.buffer, sym)
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} else {
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// the old state is no more, thus convert the buffer
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p.tokens = append(p.tokens, buildTokenFromTerm(p.buffer))
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// let the new state begin
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p.current = p.NewState(sym)
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p.buffer = make([]rune, 0, p.bufferLen)
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p.buffer = append(p.buffer, sym)
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}
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}
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// Note. States have to have different starting symbols.
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func (p *Parser) NewState(sym rune) State {
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var found State
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found = &LowerCaseState{}
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if found.StartSym(sym) {
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return found
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}
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found = &UpperCaseState{}
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if found.StartSym(sym) {
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return found
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}
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found = &NumberCaseState{}
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if found.StartSym(sym) {
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return found
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}
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return &NonAlphaNumericCaseState{}
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}
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func (p *Parser) FlushTokens() []*analysis.Token {
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p.tokens = append(p.tokens, buildTokenFromTerm(p.buffer))
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return p.tokens
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}
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