/*
* Copyright (c) 2009 QOS.ch All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package ch.qos.cal10n.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import ch.qos.cal10n.MessageConveyorException;
import ch.qos.cal10n.util.Token.TokenType;
/**
*
* @author Ceki Gülcü
*
*/
public class TokenStream {
enum State {
START, COMMENT, KEY, SEPARATOR, VAL, TRAILING_BACKSLASH;
}
BufferedReader lineReader;
State state = State.START;
TokenStream(Reader reader) {
this.lineReader = new BufferedReader(reader);
}
List<Token> tokenize() {
List<Token> tokenList = new ArrayList<Token>();
while (true) {
String currentLine;
try {
currentLine = lineReader.readLine();
} catch (IOException e) {
throw new MessageConveyorException("Failed to read input stream", e);
}
if (currentLine == null) {
break;
}
if(state != State.TRAILING_BACKSLASH) {
state = State.START;
}
tokenizeLine(tokenList, currentLine);
tokenList.add(Token.EOL);
}
return tokenList;
}
private void tokenizeLine(List<Token> tokenList, String line) {
int len = line.length();
StringBuffer buf = new StringBuffer();
for (int pointer = 0; pointer < len; pointer++) {
char c = line.charAt(pointer);
switch (state) {
case START:
if (isWhiteSpace(c)) {
// same sate
} else if (c == '#') {
state = State.COMMENT;
return;
} else if (isNonWhiteSpaceSeparator(c)) {
state = State.SEPARATOR;
buf.append(c);
} else {
state = State.KEY;
buf.append(c);
}
break;
case KEY:
if (isWhiteSpace(c) || isNonWhiteSpaceSeparator(c)) {
tokenList.add(new Token(TokenType.KEY, buf.toString()));
buf.setLength(0);
buf.append(c);
state = State.SEPARATOR;
} else {
buf.append(c);
}
break;
case SEPARATOR:
if (isWhiteSpace(c) || isNonWhiteSpaceSeparator(c)) {
buf.append(c);
} else {
tokenList.add(new Token(TokenType.SEPARATOR, buf.toString()));
buf.setLength(0);
buf.append(c);
state = State.VAL;
}
break;
case VAL:
if(c == '\\') {
if(isTrailingBackSlash(line, pointer+1)) {
tokenList.add(new Token(TokenType.VALUE, buf.toString()));
buf.setLength(0);
state = State.TRAILING_BACKSLASH;
tokenList.add(Token.TRAILING_BACKSLASH);
return;
} else {
buf.append(c);
}
} else {
buf.append(c);
}
break;
case TRAILING_BACKSLASH:
if (!isWhiteSpace(c)) {
buf.append(c);
state = State.VAL;
}
}
}
if(state == State.VAL) {
tokenList.add(new Token(TokenType.VALUE, buf.toString()));
buf.setLength(0);
}
}
boolean isTrailingBackSlash(String line, int next) {
int len = line.length();
for(int i = next; i < len; i++) {
char c = line.charAt(i);
if(!isWhiteSpace(c))
return false;
}
return true;
}
boolean isWhiteSpace(char c) {
switch (c) {
case ' ':
case '\t':
return true;
default:
return false;
}
}
boolean isNonWhiteSpaceSeparator(char c) {
switch (c) {
case ':':
case '=':
return true;
default:
return false;
}
}
}