Fixed bug in anchors with no content. This involved refactoring the 'implicit sequence' concept (where a map and a sequence start on the same indent, but we read the sequence as more indented since the '-' is visually an indent).

src/map.cpp

@@ -75,10 +75,10 @@ namespace YAML
 				throw ParserException(Mark::null(), ErrorMsg::END_OF_MAP);
 
 			Token token = pScanner->peek();
-			if(token.type != TT_KEY && token.type != TT_VALUE && token.type != TT_BLOCK_END)
+			if(token.type != TT_KEY && token.type != TT_VALUE && token.type != TT_BLOCK_MAP_END)
 				throw ParserException(token.mark, ErrorMsg::END_OF_MAP);
 
-			if(token.type == TT_BLOCK_END) {
+			if(token.type == TT_BLOCK_MAP_END) {
 				pScanner->pop();
 				break;
 			}

src/node.cpp

@@ -93,7 +93,6 @@ namespace YAML
 				break;
 			case TT_FLOW_SEQ_START:
 			case TT_BLOCK_SEQ_START:
-			case TT_BLOCK_ENTRY:
 				m_pContent = new Sequence;
 				break;
 			case TT_FLOW_MAP_START:
@@ -265,7 +264,7 @@ namespace YAML
 		// write content
 		if(node.m_pContent)
 			node.m_pContent->Write(out);
-		else
+		else if(!node.m_alias)
 			out << Null;
 
 		return out;

src/scanner.cpp

@@ -46,6 +46,7 @@ namespace YAML
 		assert(!m_tokens.empty());  // should we be asserting here? I mean, we really just be checking
 		                            // if it's empty before peeking.
 
+//		std::cerr << "peek: (" << &m_tokens.front() << ") " << m_tokens.front() << "\n";
 		return m_tokens.front();
 	}
 
@@ -98,7 +99,7 @@ namespace YAML
 		VerifySimpleKey();
 
 		// maybe need to end some blocks
-		PopIndentTo(INPUT.column());
+		PopIndentToHere();
 
 		// *****
 		// And now branch based on the next few characters!
@@ -221,7 +222,7 @@ namespace YAML
 	{
 		m_startedStream = true;
 		m_simpleKeyAllowed = true;
-		m_indents.push(-1);
+		m_indents.push(IndentMarker(-1, IndentMarker::NONE));
 		m_anchors.clear();
 	}
 
@@ -233,7 +234,7 @@ namespace YAML
 		if(INPUT.column() > 0)
 			INPUT.ResetColumn();
 
-		PopIndentTo(-1);
+		PopAllIndents();
 		VerifyAllSimpleKeys();
 
 		m_simpleKeyAllowed = false;
@@ -244,41 +245,87 @@ namespace YAML
 	// . Pushes an indentation onto the stack, and enqueues the
 	//   proper token (sequence start or mapping start).
 	// . Returns the token it generates (if any).
-	Token *Scanner::PushIndentTo(int column, bool sequence)
+	Token *Scanner::PushIndentTo(int column, IndentMarker::INDENT_TYPE type)
 	{
 		// are we in flow?
 		if(m_flowLevel > 0)
 			return 0;
+		
+		IndentMarker indent(column, type);
+		const IndentMarker& lastIndent = m_indents.top();
 
 		// is this actually an indentation?
-		if(column <= m_indents.top())
+		if(indent.column < lastIndent.column)
+			return 0;
+		if(indent.column == lastIndent.column && !(indent.type == IndentMarker::SEQ && lastIndent.type == IndentMarker::MAP))
 			return 0;
 
 		// now push
-		m_indents.push(column);
-		if(sequence)
+		m_indents.push(indent);
+		if(type == IndentMarker::SEQ)
 			m_tokens.push(Token(TT_BLOCK_SEQ_START, INPUT.mark()));
-		else
+		else if(type == IndentMarker::MAP)
 			m_tokens.push(Token(TT_BLOCK_MAP_START, INPUT.mark()));
+		else
+			assert(false);
 
 		return &m_tokens.back();
 	}
 
-	// PopIndentTo
-	// . Pops indentations off the stack until we reach 'column' indentation,
+	// PopIndentToHere
+	// . Pops indentations off the stack until we reach the current indentation level,
 	//   and enqueues the proper token each time.
-	void Scanner::PopIndentTo(int column)
+	void Scanner::PopIndentToHere()
 	{
 		// are we in flow?
 		if(m_flowLevel > 0)
 			return;
 
 		// now pop away
-		while(!m_indents.empty() && m_indents.top() > column) {
-			m_indents.pop();
-			m_tokens.push(Token(TT_BLOCK_END, INPUT.mark()));
+		while(!m_indents.empty()) {
+			const IndentMarker& indent = m_indents.top();
+			if(indent.column < INPUT.column())
+				break;
+			if(indent.column == INPUT.column() && !(indent.type == IndentMarker::SEQ && !Exp::BlockEntry.Matches(INPUT)))
+				break;
+				
+			PopIndent();
 		}
 	}
+	
+	// PopAllIndents
+	// . Pops all indentations off the stack,
+	//   and enqueues the proper token each time.
+	void Scanner::PopAllIndents()
+	{
+		// are we in flow?
+		if(m_flowLevel > 0)
+			return;
+
+		// now pop away
+		while(!m_indents.empty())
+			PopIndent();
+	}
+	
+	// PopIndent
+	// . Pops a single indent, pushing the proper token
+	void Scanner::PopIndent()
+	{
+		IndentMarker::INDENT_TYPE type = m_indents.top().type;
+		m_indents.pop();
+		if(type == IndentMarker::SEQ)
+			m_tokens.push(Token(TT_BLOCK_SEQ_END, INPUT.mark()));
+		else if(type == IndentMarker::MAP)
+			m_tokens.push(Token(TT_BLOCK_MAP_END, INPUT.mark()));
+	}
+
+	// GetTopIndent
+	int Scanner::GetTopIndent() const
+	{
+		if(m_indents.empty())
+			return 0;
+		return m_indents.top().column;
+	}
 
 	// Save
 	// . Saves a pointer to the Node object referenced by a particular anchor

src/scanner.h

@@ -34,14 +34,26 @@ namespace YAML
 		void ClearAnchors();
 
 	private:
+		struct IndentMarker {
+			enum INDENT_TYPE { MAP, SEQ, NONE };
+			IndentMarker(int column_, INDENT_TYPE type_): column(column_), type(type_) {}
+		
+			int column;
+			INDENT_TYPE type;
+		};
+	
+	private:	
 		// scanning
 		void EnsureTokensInQueue();
 		void ScanNextToken();
 		void ScanToNextToken();
 		void StartStream();
 		void EndStream();
-		Token *PushIndentTo(int column, bool sequence);
-		void PopIndentTo(int column);
+		Token *PushIndentTo(int column, IndentMarker::INDENT_TYPE type);
+		void PopIndentToHere();
+		void PopAllIndents();
+		void PopIndent();
+		int GetTopIndent() const;
 
 		// checking input
 		void InsertSimpleKey();
@@ -94,7 +106,7 @@ namespace YAML
 		int m_flowLevel;                // number of unclosed '[' and '{' indicators
 		bool m_isLastKeyValid;
 		std::stack <SimpleKey> m_simpleKeys;
-		std::stack <int> m_indents;
+		std::stack <IndentMarker> m_indents;
 		std::map <std::string, const Node *> m_anchors;
 	};
 }

src/scantoken.cpp

@@ -19,7 +19,7 @@ namespace YAML
 		std::vector <std::string> params;
 
 		// pop indents and simple keys
-		PopIndentTo(-1);
+		PopAllIndents();
 		VerifyAllSimpleKeys();
 
 		m_simpleKeyAllowed = false;
@@ -59,7 +59,7 @@ namespace YAML
 	// DocStart
 	void Scanner::ScanDocStart()
 	{
-		PopIndentTo(-1);
+		PopAllIndents();
 		VerifyAllSimpleKeys();
 		m_simpleKeyAllowed = false;
 
@@ -72,7 +72,7 @@ namespace YAML
 	// DocEnd
 	void Scanner::ScanDocEnd()
 	{
-		PopIndentTo(-1);
+		PopAllIndents();
 		VerifyAllSimpleKeys();
 		m_simpleKeyAllowed = false;
 
@@ -135,7 +135,7 @@ namespace YAML
 		if(!m_simpleKeyAllowed)
 			throw ParserException(INPUT.mark(), ErrorMsg::BLOCK_ENTRY);
 
-		PushIndentTo(INPUT.column(), true);
+		PushIndentTo(INPUT.column(), IndentMarker::SEQ);
 		m_simpleKeyAllowed = true;
 
 		// eat
@@ -152,7 +152,7 @@ namespace YAML
 			if(!m_simpleKeyAllowed)
 				throw ParserException(INPUT.mark(), ErrorMsg::MAP_KEY);
 
-			PushIndentTo(INPUT.column(), false);
+			PushIndentTo(INPUT.column(), IndentMarker::MAP);
 		}
 
 		// can only put a simple key here if we're in block context
@@ -180,7 +180,7 @@ namespace YAML
 				if(!m_simpleKeyAllowed)
 					throw ParserException(INPUT.mark(), ErrorMsg::MAP_VALUE);
 
-				PushIndentTo(INPUT.column(), false);
+				PushIndentTo(INPUT.column(), IndentMarker::MAP);
 			}
 
 			// can only put a simple key here if we're in block context
@@ -277,7 +277,7 @@ namespace YAML
 		ScanScalarParams params;
 		params.end = (m_flowLevel > 0 ? Exp::EndScalarInFlow : Exp::EndScalar) || (Exp::BlankOrBreak + Exp::Comment);
 		params.eatEnd = false;
-		params.indent = (m_flowLevel > 0 ? 0 : m_indents.top() + 1);
+		params.indent = (m_flowLevel > 0 ? 0 : GetTopIndent() + 1);
 		params.fold = true;
 		params.eatLeadingWhitespace = true;
 		params.trimTrailingSpaces = true;
@@ -391,8 +391,8 @@ namespace YAML
 			throw ParserException(INPUT.mark(), ErrorMsg::CHAR_IN_BLOCK);
 
 		// set the initial indentation
-		if(m_indents.top() >= 0)
-			params.indent += m_indents.top();
+		if(GetTopIndent() >= 0)
+			params.indent += GetTopIndent();
 
 		params.eatLeadingWhitespace = false;
 		params.trimTrailingSpaces = false;

src/sequence.cpp

@@ -83,11 +83,11 @@ namespace YAML
 				throw ParserException(Mark::null(), ErrorMsg::END_OF_SEQ);
 
 			Token token = pScanner->peek();
-			if(token.type != TT_BLOCK_ENTRY && token.type != TT_BLOCK_END)
+			if(token.type != TT_BLOCK_ENTRY && token.type != TT_BLOCK_SEQ_END)
 				throw ParserException(token.mark, ErrorMsg::END_OF_SEQ);
 
 			pScanner->pop();
-			if(token.type == TT_BLOCK_END)
+			if(token.type == TT_BLOCK_SEQ_END)
 				break;
 
 			Node *pNode = new Node;
@@ -96,7 +96,7 @@ namespace YAML
 			// check for null
 			if(!pScanner->empty()) {
 				const Token& token = pScanner->peek();
-				if(token.type == TT_BLOCK_ENTRY || token.type == TT_BLOCK_END)
+				if(token.type == TT_BLOCK_ENTRY || token.type == TT_BLOCK_SEQ_END)
 					continue;
 			}
 			

src/simplekey.cpp

@@ -35,7 +35,7 @@ namespace YAML
 		SimpleKey key(INPUT.mark(), m_flowLevel);
 
 		// first add a map start, if necessary
-		key.pMapStart = PushIndentTo(INPUT.column(), false);
+		key.pMapStart = PushIndentTo(INPUT.column(), IndentMarker::MAP);
 		if(key.pMapStart)
 			key.pMapStart->status = TS_UNVERIFIED;
 

src/token.h

@@ -18,7 +18,8 @@ namespace YAML
 		TT_DOC_END,
 		TT_BLOCK_SEQ_START,
 		TT_BLOCK_MAP_START,
-		TT_BLOCK_END,
+		TT_BLOCK_SEQ_END,
+		TT_BLOCK_MAP_END,
 		TT_BLOCK_ENTRY,
 		TT_FLOW_SEQ_START,
 		TT_FLOW_MAP_START,
@@ -39,7 +40,8 @@ namespace YAML
 		"DOC_END",
 		"BLOCK_SEQ_START",
 		"BLOCK_MAP_START",
-		"BLOCK_END",
+		"BLOCK_SEQ_END",
+		"BLOCK_MAP_END",
 		"BLOCK_ENTRY",
 		"FLOW_SEQ_START",
 		"FLOW_MAP_START",

yaml-reader/emittertests.cpp

@@ -272,6 +272,16 @@ namespace Test
 			desiredOutput = "- &fred\n  name: Fred\n  age: 42\n- *fred";
 		}
 
+		void AliasAndAnchorWithNull(YAML::Emitter& out, std::string& desiredOutput)
+		{
+			out << YAML::BeginSeq;
+			out << YAML::Anchor("fred") << YAML::Null;
+			out << YAML::Alias("fred");
+			out << YAML::EndSeq;
+			
+			desiredOutput = "- &fred ~\n- *fred";
+		}
+
 		void ComplexDoc(YAML::Emitter& out, std::string& desiredOutput)
 		{
 			out << YAML::BeginMap;

yaml-reader/parsertests.cpp

@@ -248,6 +248,30 @@ namespace Test
 			return true;
 		}
 
+		bool CompressedMapAndSeq()
+		{
+			std::string input = "key:\n- one\n- two";
+			
+			std::stringstream stream(input);
+			YAML::Parser parser(stream);
+			YAML::Node doc;
+			parser.GetNextDocument(doc);
+			
+			const YAML::Node& seq = doc["key"];
+			if(seq.size() != 2)
+				return false;
+				
+			std::string output;
+			seq[0] >> output;
+			if(output != "one")
+				return false;
+			seq[1] >> output;
+			if(output != "two")
+				return false;
+
+			return true;
+		}
+
 		bool NullBlockSeqEntry()
 		{
 			std::string input = "- hello\n-\n- world";
@@ -301,5 +325,50 @@ namespace Test
 			
 			return true;
 		}
+
+		bool SimpleAlias()
+		{
+			std::string input = "- &alias test\n- *alias";
+			
+			std::stringstream stream(input);
+			YAML::Parser parser(stream);
+			YAML::Node doc;
+			parser.GetNextDocument(doc);
+			
+			std::string output;
+			doc[0] >> output;
+			if(output != "test")
+				return false;
+			
+			doc[1] >> output;
+			if(output != "test")
+				return false;
+			
+			if(doc.size() != 2)
+				return false;
+			
+			return true;
+		}
+		
+		bool AliasWithNull()
+		{
+			std::string input = "- &alias\n- *alias";
+			
+			std::stringstream stream(input);
+			YAML::Parser parser(stream);
+			YAML::Node doc;
+			parser.GetNextDocument(doc);
+			
+			if(!IsNull(doc[0]))
+				return false;
+			
+			if(!IsNull(doc[1]))
+				return false;
+			
+			if(doc.size() != 2)
+				return false;
+			
+			return true;
+		}
 	}
 }

yaml-reader/tests.cpp

@@ -263,9 +263,12 @@ namespace Test
 		RunParserTest(&Parser::FlowSeq, "flow seq", passed);
 		RunParserTest(&Parser::FlowMap, "flow map", passed);
 		RunParserTest(&Parser::QuotedSimpleKeys, "quoted simple keys", passed);
+		RunParserTest(&Parser::CompressedMapAndSeq, "compressed map and seq", passed);
 		RunParserTest(&Parser::NullBlockSeqEntry, "null block seq entry", passed);
 		RunParserTest(&Parser::NullBlockMapKey, "null block map key", passed);
 		RunParserTest(&Parser::NullBlockMapValue, "null block map value", passed);
+		RunParserTest(&Parser::SimpleAlias, "simple alias", passed);
+		RunParserTest(&Parser::AliasWithNull, "alias with null", passed);
 		
 		RunEncodingTest(&EncodeToUtf8, false, "UTF-8, no BOM", passed);
 		RunEncodingTest(&EncodeToUtf8, true, "UTF-8 with BOM", passed);
@@ -346,6 +349,7 @@ namespace Test
 		RunEmitterTest(&Emitter::LongKeyFlowMap, "long key flow map", passed);
 		RunEmitterTest(&Emitter::BlockMapAsKey, "block map as key", passed);
 		RunEmitterTest(&Emitter::AliasAndAnchor, "alias and anchor", passed);
+		RunEmitterTest(&Emitter::AliasAndAnchorWithNull, "alias and anchor with null", passed);
 		RunEmitterTest(&Emitter::ComplexDoc, "complex doc", passed);
 		RunEmitterTest(&Emitter::STLContainers, "STL containers", passed);
 		RunEmitterTest(&Emitter::SimpleComment, "simple comment", passed);

yaml-reader/tests.h

@@ -34,9 +34,12 @@ namespace Test {
 		bool FlowSeq();
 		bool FlowMap();
 		bool QuotedSimpleKeys();
+		bool CompressedMapAndSeq();
 		bool NullBlockSeqEntry();
 		bool NullBlockMapKey();
 		bool NullBlockMapValue();
+		bool SimpleAlias();
+		bool AliasWithNull();
 	}
 	
 	namespace Emitter {
@@ -63,6 +66,7 @@ namespace Test {
 		void LongKeyFlowMap(YAML::Emitter& out, std::string& desiredOutput);
 		void BlockMapAsKey(YAML::Emitter& out, std::string& desiredOutput);
 		void AliasAndAnchor(YAML::Emitter& out, std::string& desiredOutput);
+		void AliasAndAnchorWithNull(YAML::Emitter& out, std::string& desiredOutput);
 		void ComplexDoc(YAML::Emitter& out, std::string& desiredOutput);
 		void STLContainers(YAML::Emitter& out, std::string& desiredOutput);
 		void SimpleComment(YAML::Emitter& out, std::string& desiredOutput);