| /** |
| * Copyright (c) 2008-2012, 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 org.yaml.snakeyaml.DumperOptions.Version; |
| import org.yaml.snakeyaml.events.AliasEvent; |
| import org.yaml.snakeyaml.events.DocumentEndEvent; |
| import org.yaml.snakeyaml.events.DocumentStartEvent; |
| import org.yaml.snakeyaml.events.Event; |
| import org.yaml.snakeyaml.events.ImplicitTuple; |
| import org.yaml.snakeyaml.events.MappingEndEvent; |
| import org.yaml.snakeyaml.events.MappingStartEvent; |
| import org.yaml.snakeyaml.events.ScalarEvent; |
| import org.yaml.snakeyaml.events.SequenceEndEvent; |
| import org.yaml.snakeyaml.events.SequenceStartEvent; |
| import org.yaml.snakeyaml.events.StreamEndEvent; |
| import org.yaml.snakeyaml.events.StreamStartEvent; |
| import org.yaml.snakeyaml.parser.Parser; |
| import org.yaml.snakeyaml.tokens.AliasToken; |
| import org.yaml.snakeyaml.tokens.AnchorToken; |
| import org.yaml.snakeyaml.tokens.ScalarToken; |
| import org.yaml.snakeyaml.tokens.TagToken; |
| import org.yaml.snakeyaml.tokens.Token; |
| |
| public class CanonicalParser implements Parser { |
| private ArrayList<Event> events; |
| private boolean parsed; |
| private CanonicalScanner scanner; |
| |
| public CanonicalParser(String data) { |
| events = new ArrayList<Event>(); |
| parsed = false; |
| scanner = new CanonicalScanner(data); |
| } |
| |
| // stream: STREAM-START document* STREAM-END |
| private void parseStream() { |
| scanner.getToken(Token.ID.StreamStart); |
| events.add(new StreamStartEvent(null, null)); |
| while (!scanner.checkToken(Token.ID.StreamEnd)) { |
| if (scanner.checkToken(Token.ID.Directive, Token.ID.DocumentStart)) { |
| parseDocument(); |
| } else { |
| throw new CanonicalException("document is expected, got " + scanner.tokens.get(0)); |
| } |
| } |
| scanner.getToken(Token.ID.StreamEnd); |
| events.add(new StreamEndEvent(null, null)); |
| } |
| |
| // document: DIRECTIVE? DOCUMENT-START node |
| private void parseDocument() { |
| if (scanner.checkToken(Token.ID.Directive)) { |
| scanner.getToken(Token.ID.Directive); |
| } |
| scanner.getToken(Token.ID.DocumentStart); |
| events.add(new DocumentStartEvent(null, null, true, Version.V1_1, null)); |
| parseNode(); |
| events.add(new DocumentEndEvent(null, null, true)); |
| } |
| |
| // node: ALIAS | ANCHOR? TAG? (SCALAR|sequence|mapping) |
| private void parseNode() { |
| if (scanner.checkToken(Token.ID.Alias)) { |
| AliasToken token = (AliasToken) scanner.getToken(); |
| events.add(new AliasEvent(token.getValue(), null, null)); |
| } else { |
| String anchor = null; |
| if (scanner.checkToken(Token.ID.Anchor)) { |
| AnchorToken token = (AnchorToken) scanner.getToken(); |
| anchor = token.getValue(); |
| } |
| String tag = null; |
| if (scanner.checkToken(Token.ID.Tag)) { |
| TagToken token = (TagToken) scanner.getToken(); |
| tag = token.getValue().getHandle() + token.getValue().getSuffix(); |
| } |
| if (scanner.checkToken(Token.ID.Scalar)) { |
| ScalarToken token = (ScalarToken) scanner.getToken(); |
| events.add(new ScalarEvent(anchor, tag, new ImplicitTuple(false, false), token |
| .getValue(), null, null, null)); |
| } else if (scanner.checkToken(Token.ID.FlowSequenceStart)) { |
| events.add(new SequenceStartEvent(anchor, tag, false, null, null, null)); |
| parseSequence(); |
| } else if (scanner.checkToken(Token.ID.FlowMappingStart)) { |
| events.add(new MappingStartEvent(anchor, tag, false, null, null, null)); |
| parseMapping(); |
| } else { |
| throw new CanonicalException("SCALAR, '[', or '{' is expected, got " |
| + scanner.tokens.get(0)); |
| } |
| } |
| } |
| |
| // sequence: SEQUENCE-START (node (ENTRY node)*)? ENTRY? SEQUENCE-END |
| private void parseSequence() { |
| scanner.getToken(Token.ID.FlowSequenceStart); |
| if (!scanner.checkToken(Token.ID.FlowSequenceEnd)) { |
| parseNode(); |
| while (!scanner.checkToken(Token.ID.FlowSequenceEnd)) { |
| scanner.getToken(Token.ID.FlowEntry); |
| if (!scanner.checkToken(Token.ID.FlowSequenceEnd)) { |
| parseNode(); |
| } |
| } |
| } |
| scanner.getToken(Token.ID.FlowSequenceEnd); |
| events.add(new SequenceEndEvent(null, null)); |
| } |
| |
| // mapping: MAPPING-START (map_entry (ENTRY map_entry)*)? ENTRY? MAPPING-END |
| private void parseMapping() { |
| scanner.getToken(Token.ID.FlowMappingStart); |
| if (!scanner.checkToken(Token.ID.FlowMappingEnd)) { |
| parseMapEntry(); |
| while (!scanner.checkToken(Token.ID.FlowMappingEnd)) { |
| scanner.getToken(Token.ID.FlowEntry); |
| if (!scanner.checkToken(Token.ID.FlowMappingEnd)) { |
| parseMapEntry(); |
| } |
| } |
| } |
| scanner.getToken(Token.ID.FlowMappingEnd); |
| events.add(new MappingEndEvent(null, null)); |
| } |
| |
| // map_entry: KEY node VALUE node |
| private void parseMapEntry() { |
| scanner.getToken(Token.ID.Key); |
| parseNode(); |
| scanner.getToken(Token.ID.Value); |
| parseNode(); |
| } |
| |
| public void parse() { |
| parseStream(); |
| parsed = true; |
| } |
| |
| public Event getEvent() { |
| if (!parsed) { |
| parse(); |
| } |
| return events.remove(0); |
| } |
| |
| /** |
| * Check the type of the next event. |
| */ |
| public boolean checkEvent(Event.ID choice) { |
| if (!parsed) { |
| parse(); |
| } |
| if (!events.isEmpty()) { |
| if (events.get(0).is(choice)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Get the next event. |
| */ |
| public Event peekEvent() { |
| if (!parsed) { |
| parse(); |
| } |
| if (events.isEmpty()) { |
| return null; |
| } else { |
| return events.get(0); |
| } |
| } |
| } |