109 lines
2.7 KiB
Go
109 lines
2.7 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 (
|
|
"github.com/blevesearch/bleve/analysis"
|
|
)
|
|
|
|
func (p *Parser) buildTokenFromTerm(buffer []rune) *analysis.Token {
|
|
term := analysis.BuildTermFromRunes(buffer)
|
|
token := &analysis.Token{
|
|
Term: term,
|
|
Position: p.position,
|
|
Start: p.index,
|
|
End: p.index + len(term),
|
|
}
|
|
p.position++
|
|
p.index += len(term)
|
|
return token
|
|
}
|
|
|
|
// Parser accepts a symbol and passes it to the current state (representing a class).
|
|
// The state can accept it (and accumulate it). Otherwise, the parser creates a new state that
|
|
// starts with the pushed symbol.
|
|
//
|
|
// Parser accumulates a new resulting token every time it switches state.
|
|
// Use FlushTokens() to get the results after the last symbol was pushed.
|
|
type Parser struct {
|
|
bufferLen int
|
|
buffer []rune
|
|
current State
|
|
tokens []*analysis.Token
|
|
position int
|
|
index int
|
|
}
|
|
|
|
func NewParser(len, position, index int) *Parser {
|
|
return &Parser{
|
|
bufferLen: len,
|
|
buffer: make([]rune, 0, len),
|
|
tokens: make([]*analysis.Token, 0, len),
|
|
position: position,
|
|
index: index,
|
|
}
|
|
}
|
|
|
|
func (p *Parser) Push(sym rune, peek *rune) {
|
|
if p.current == nil {
|
|
// the start of parsing
|
|
p.current = p.NewState(sym)
|
|
p.buffer = append(p.buffer, sym)
|
|
|
|
} else if p.current.Member(sym, peek) {
|
|
// same state, just accumulate
|
|
p.buffer = append(p.buffer, sym)
|
|
|
|
} else {
|
|
// the old state is no more, thus convert the buffer
|
|
p.tokens = append(p.tokens, p.buildTokenFromTerm(p.buffer))
|
|
|
|
// let the new state begin
|
|
p.current = p.NewState(sym)
|
|
p.buffer = make([]rune, 0, p.bufferLen)
|
|
p.buffer = append(p.buffer, sym)
|
|
}
|
|
}
|
|
|
|
// Note. States have to have different starting symbols.
|
|
func (p *Parser) NewState(sym rune) State {
|
|
var found State
|
|
|
|
found = &LowerCaseState{}
|
|
if found.StartSym(sym) {
|
|
return found
|
|
}
|
|
|
|
found = &UpperCaseState{}
|
|
if found.StartSym(sym) {
|
|
return found
|
|
}
|
|
|
|
found = &NumberCaseState{}
|
|
if found.StartSym(sym) {
|
|
return found
|
|
}
|
|
|
|
return &NonAlphaNumericCaseState{}
|
|
}
|
|
|
|
func (p *Parser) FlushTokens() []*analysis.Token {
|
|
p.tokens = append(p.tokens, p.buildTokenFromTerm(p.buffer))
|
|
return p.tokens
|
|
}
|
|
|
|
func (p *Parser) NextPosition() int {
|
|
return p.position
|
|
}
|