platform_system_core/init/parser/tokenizer.cpp

129 lines
2.8 KiB
C++

// Copyright (C) 2015 The Android Open Source Project
//
// 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.
#include "tokenizer.h"
namespace init {
Tokenizer::Tokenizer(const std::string& data)
: data_(data), eof_(false), pos_(0), tok_start_(0) {
current_.type = TOK_START;
if (data.size() > 0) {
cur_char_ = data[0];
} else {
eof_ = true;
cur_char_ = '\0';
}
}
Tokenizer::~Tokenizer() {}
const Tokenizer::Token& Tokenizer::current() {
return current_;
}
bool Tokenizer::Next() {
while (!eof_) {
AdvWhiteSpace();
// Check for comments.
if (cur_char_ == '#') {
AdvChar();
// Skip rest of line
while (!eof_ && cur_char_ != '\n') {
AdvChar();
}
}
if (eof_) {
break;
}
if (cur_char_ == '\0') {
AdvChar();
} else if (cur_char_ == '\n') {
current_.type = TOK_NEWLINE;
current_.text.clear();
AdvChar();
return true;
} else if (cur_char_ == '\\') {
AdvChar(); // skip backslash
// This is line continuation so
// do not generated TOK_NEWLINE at
// the next \n.
AdvUntil('\n');
AdvChar(); // skip \n
} else if (cur_char_ == '\"') {
AdvChar();
StartText();
// Grab everything until the next quote.
AdvUntil('\"');
EndText();
AdvChar(); // skip quote.
return true;
} else {
StartText();
AdvText();
EndText();
return true;
}
}
current_.type = TOK_END;
current_.text.clear();
return false;
}
void Tokenizer::AdvChar() {
pos_++;
if (pos_ < data_.size()) {
cur_char_ = data_[pos_];
} else {
eof_ = true;
cur_char_ = '\0';
}
}
void Tokenizer::AdvWhiteSpace() {
while (cur_char_ == '\t' || cur_char_ == '\r' || cur_char_ == ' ') {
AdvChar();
}
}
void Tokenizer::AdvUntil(char x) {
while (!eof_ && cur_char_ != x) {
AdvChar();
}
}
void Tokenizer::AdvText() {
while (cur_char_ != '\t' && cur_char_ != '\r' && cur_char_ != '\0' &&
cur_char_ != ' ' && cur_char_ != '\n' && cur_char_ != '#') {
AdvChar();
}
}
void Tokenizer::StartText() {
current_.text.clear();
tok_start_ = pos_;
current_.type = TOK_TEXT;
}
void Tokenizer::EndText() {
if (pos_ != tok_start_) {
current_.text.append(data_, tok_start_, pos_ - tok_start_);
}
}
} // namespace init