/**
* Copyright (c) 2008-2011, http://www.snakeyaml.org
*
* 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 org.pyyaml;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.yaml.snakeyaml.error.Mark;
import org.yaml.snakeyaml.nodes.Tag;
import org.yaml.snakeyaml.scanner.Scanner;
import org.yaml.snakeyaml.scanner.ScannerImpl;
import org.yaml.snakeyaml.tokens.AliasToken;
import org.yaml.snakeyaml.tokens.AnchorToken;
import org.yaml.snakeyaml.tokens.DirectiveToken;
import org.yaml.snakeyaml.tokens.DocumentStartToken;
import org.yaml.snakeyaml.tokens.FlowEntryToken;
import org.yaml.snakeyaml.tokens.FlowMappingEndToken;
import org.yaml.snakeyaml.tokens.FlowMappingStartToken;
import org.yaml.snakeyaml.tokens.FlowSequenceEndToken;
import org.yaml.snakeyaml.tokens.FlowSequenceStartToken;
import org.yaml.snakeyaml.tokens.KeyToken;
import org.yaml.snakeyaml.tokens.ScalarToken;
import org.yaml.snakeyaml.tokens.StreamEndToken;
import org.yaml.snakeyaml.tokens.StreamStartToken;
import org.yaml.snakeyaml.tokens.TagToken;
import org.yaml.snakeyaml.tokens.TagTuple;
import org.yaml.snakeyaml.tokens.Token;
import org.yaml.snakeyaml.tokens.ValueToken;
public class CanonicalScanner implements Scanner {
private static final String DIRECTIVE = "%YAML 1.1";
private final static Map<Character, Integer> QUOTE_CODES = ScannerImpl.ESCAPE_CODES;
private final static Map<Character, String> QUOTE_REPLACES = ScannerImpl.ESCAPE_REPLACEMENTS;
private String data;
private int index;
public ArrayList<Token> tokens;
private boolean scanned;
private Mark mark;
public CanonicalScanner(String data) {
this.data = data + "\0";
this.index = 0;
this.tokens = new ArrayList<Token>();
this.scanned = false;
this.mark = new Mark("test", 0, 0, 0, data, 0);
}
public boolean checkToken(Token.ID... choices) {
if (!scanned) {
scan();
}
if (!tokens.isEmpty()) {
if (choices.length == 0) {
return true;
}
Token first = this.tokens.get(0);
for (Token.ID choice : choices) {
if (first.getTokenId() == choice) {
return true;
}
}
}
return false;
}
public Token peekToken() {
if (!scanned) {
scan();
}
if (!tokens.isEmpty()) {
return this.tokens.get(0);
}
return null;
}
public Token getToken() {
if (!scanned) {
scan();
}
return this.tokens.remove(0);
}
public Token getToken(Token.ID choice) {
Token token = getToken();
if (choice != null && token.getTokenId() != choice) {
throw new CanonicalException("unexpected token " + token);
}
return token;
}
private void scan() {
this.tokens.add(new StreamStartToken(mark, mark));
boolean stop = false;
while (!stop) {
findToken();
char ch = data.charAt(index);
switch (ch) {
case '\0':
tokens.add(new StreamEndToken(mark, mark));
stop = true;
break;
case '%':
tokens.add(scanDirective());
break;
case '-':
if ("---".equals(data.substring(index, index + 3))) {
index += 3;
tokens.add(new DocumentStartToken(mark, mark));
}
break;
case '[':
index++;
tokens.add(new FlowSequenceStartToken(mark, mark));
break;
case '{':
index++;
tokens.add(new FlowMappingStartToken(mark, mark));
break;
case ']':
index++;
tokens.add(new FlowSequenceEndToken(mark, mark));
break;
case '}':
index++;
tokens.add(new FlowMappingEndToken(mark, mark));
break;
case '?':
index++;
tokens.add(new KeyToken(mark, mark));
break;
case ':':
index++;
tokens.add(new ValueToken(mark, mark));
break;
case ',':
index++;
tokens.add(new FlowEntryToken(mark, mark));
break;
case '*':
tokens.add(scanAlias());
break;
case '&':
tokens.add(scanAlias());
break;
case '!':
tokens.add(scanTag());
break;
case '"':
tokens.add(scanScalar());
break;
default:
throw new CanonicalException("invalid token");
}
}
scanned = true;
}
private Token scanDirective() {
String chunk1 = data.substring(index, index + DIRECTIVE.length());
char chunk2 = data.charAt(index + DIRECTIVE.length());
if (DIRECTIVE.equals(chunk1) && "\n\0".indexOf(chunk2) != -1) {
index += DIRECTIVE.length();
List<Integer> implicit = new ArrayList<Integer>(2);
implicit.add(new Integer(1));
implicit.add(new Integer(1));
return new DirectiveToken<Integer>("YAML", implicit, mark, mark);
} else {
throw new CanonicalException("invalid directive");
}
}
private Token scanAlias() {
boolean isTokenClassAlias;
if (data.charAt(index) == '*') {
isTokenClassAlias = true;
} else {
isTokenClassAlias = false;
}
index++;
int start = index;
while (", \n\0".indexOf(data.charAt(index)) == -1) {
index++;
}
String value = data.substring(start, index);
Token token;
if (isTokenClassAlias) {
token = new AliasToken(value, mark, mark);
} else {
token = new AnchorToken(value, mark, mark);
}
return token;
}
private Token scanTag() {
index++;
int start = index;
while (" \n\0".indexOf(data.charAt(index)) == -1) {
index++;
}
String value = data.substring(start, index);
if (value.length() == 0) {
value = "!";
} else if (value.charAt(0) == '!') {
value = Tag.PREFIX + value.substring(1);
} else if (value.charAt(0) == '<' && value.charAt(value.length() - 1) == '>') {
value = value.substring(1, value.length() - 1);
} else {
value = "!" + value;
}
return new TagToken(new TagTuple("", value), mark, mark);
}
private Token scanScalar() {
index++;
StringBuilder chunks = new StringBuilder();
int start = index;
boolean ignoreSpaces = false;
while (data.charAt(index) != '"') {
if (data.charAt(index) == '\\') {
ignoreSpaces = false;
chunks.append(data.substring(start, index));
index++;
char ch = data.charAt(index);
index++;
if (ch == '\n') {
ignoreSpaces = true;
} else if (QUOTE_CODES.keySet().contains(ch)) {
int length = QUOTE_CODES.get(ch);
int code = Integer.parseInt(data.substring(index, index + length), 16);
chunks.append(String.valueOf((char) code));
index += length;
} else {
if (!QUOTE_REPLACES.keySet().contains(ch)) {
throw new CanonicalException("invalid escape code");
}
chunks.append(QUOTE_REPLACES.get(ch));
}
start = index;
} else if (data.charAt(index) == '\n') {
chunks.append(data.substring(start, index));
chunks.append(" ");
index++;
start = index;
ignoreSpaces = true;
} else if (ignoreSpaces && data.charAt(index) == ' ') {
index++;
start = index;
} else {
ignoreSpaces = false;
index++;
}
}
chunks.append(data.substring(start, index));
index++;
return new ScalarToken(chunks.toString(), mark, mark, false);
}
private void findToken() {
boolean found = false;
while (!found) {
while (" \t".indexOf(data.charAt(index)) != -1) {
index++;
}
if (data.charAt(index) == '#') {
while (data.charAt(index) != '\n') {
index++;
}
}
if (data.charAt(index) == '\n') {
index++;
} else {
found = true;
}
}
}
}