Added a (recursive) ordering, so we have a canonical output that we can compare.

content.h

@@ -5,12 +5,16 @@
 #include <map>
 #include "parserstate.h"
 #include "exceptions.h"
+#include "ltnode.h"
 
 namespace YAML
 {
 	class Scanner;
 	class Parser;
 	class Node;
+	class Scalar;
+	class Sequence;
+	class Map;
 
 	class Content
 	{
@@ -22,9 +26,9 @@ namespace YAML
 		virtual void Write(std::ostream& out, int indent, bool startedLine, bool onlyOneCharOnLine) = 0;
 
 		virtual bool GetBegin(std::vector <Node *>::const_iterator& it) const { return false; }
-		virtual bool GetBegin(std::map <Node *, Node *>::const_iterator& it) const { return false; }
+		virtual bool GetBegin(std::map <Node *, Node *, ltnode>::const_iterator& it) const { return false; }
 		virtual bool GetEnd(std::vector <Node *>::const_iterator& it) const { return false; }
-		virtual bool GetEnd(std::map <Node *, Node *>::const_iterator& it) const { return false; }
+		virtual bool GetEnd(std::map <Node *, Node *, ltnode>::const_iterator& it) const { return false; }
 		virtual Node *GetNode(unsigned i) const { return 0; }
 		virtual unsigned GetSize() const { return 0; }
 
@@ -37,6 +41,12 @@ namespace YAML
 		virtual void Read(double& d) { throw InvalidScalar(); }
 		virtual void Read(char& c) { throw InvalidScalar(); }
 
+		// ordering
+		virtual int Compare(Content *pContent) { return 0; }
+		virtual int Compare(Scalar *pScalar) { return 0; }
+		virtual int Compare(Sequence *pSeq) { return 0; }
+		virtual int Compare(Map *pMap) { return 0; }
+
 	protected:
 	};
 }

iterator.cpp

@@ -11,7 +11,7 @@ namespace YAML
 	{
 	}
 
-	Node::Iterator::Iterator(std::map <Node *, Node *>::const_iterator it): mapIter(it), type(IT_MAP)
+	Node::Iterator::Iterator(std::map <Node *, Node *, ltnode>::const_iterator it): mapIter(it), type(IT_MAP)
 	{
 	}
 

ltnode.h

+#pragma once
+
+namespace YAML
+{
+	class Node;
+
+	struct ltnode {
+		bool operator()(const Node *pNode1, const Node *pNode2) const;
+	};
+}

map.cpp

@@ -24,13 +24,13 @@ namespace YAML
 		m_data.clear();
 	}
 
-	bool Map::GetBegin(std::map <Node *, Node *>::const_iterator& it) const
+	bool Map::GetBegin(std::map <Node *, Node *, ltnode>::const_iterator& it) const
 	{
 		it = m_data.begin();
 		return true;
 	}
 
-	bool Map::GetEnd(std::map <Node *, Node *>::const_iterator& it) const
+	bool Map::GetEnd(std::map <Node *, Node *, ltnode>::const_iterator& it) const
 	{
 		it = m_data.end();
 		return true;
@@ -68,15 +68,22 @@ namespace YAML
 
 			Node *pKey = new Node;
 			Node *pValue = new Node;
-			m_data[pKey] = pValue;
 
-			// grab key
-			pKey->Parse(pScanner, state);
-
-			// now grab value (optional)
-			if(pScanner->PeekNextToken() && pScanner->PeekNextToken()->type == TT_VALUE) {
-				pScanner->PopNextToken();
-				pValue->Parse(pScanner, state);
+			try {
+				// grab key
+				pKey->Parse(pScanner, state);
+
+				// now grab value (optional)
+				if(pScanner->PeekNextToken() && pScanner->PeekNextToken()->type == TT_VALUE) {
+					pScanner->PopNextToken();
+					pValue->Parse(pScanner, state);
+				}
+
+				m_data[pKey] = pValue;
+			} catch(Exception& e) {
+				delete pKey;
+				delete pValue;
+				throw e;
 			}
 		}
 	}
@@ -105,23 +112,31 @@ namespace YAML
 
 			Node *pKey = new Node;
 			Node *pValue = new Node;
-			m_data[pKey] = pValue;
-
-			// grab key
-			pKey->Parse(pScanner, state);
 
-			// now grab value (optional)
-			if(pScanner->PeekNextToken() && pScanner->PeekNextToken()->type == TT_VALUE) {
-				pScanner->PopNextToken();
-				pValue->Parse(pScanner, state);
+			try {
+				// grab key
+				pKey->Parse(pScanner, state);
+
+				// now grab value (optional)
+				if(pScanner->PeekNextToken() && pScanner->PeekNextToken()->type == TT_VALUE) {
+					pScanner->PopNextToken();
+					pValue->Parse(pScanner, state);
+				}
+
+				// now eat the separator (or could be a map end, which we ignore - but if it's neither, then it's a bad node)
+				pToken = pScanner->PeekNextToken();
+				if(pToken->type == TT_FLOW_ENTRY)
+					pScanner->EatNextToken();
+				else if(pToken->type != TT_FLOW_MAP_END)
+					throw MapEndNotFound();
+
+				m_data[pKey] = pValue;
+			} catch(Exception& e) {
+				// clean up and rethrow
+				delete pKey;
+				delete pValue;
+				throw e;
 			}
-
-			// now eat the separator (or could be a map end, which we ignore - but if it's neither, then it's a bad node)
-			pToken = pScanner->PeekNextToken();
-			if(pToken->type == TT_FLOW_ENTRY)
-				pScanner->EatNextToken();
-			else if(pToken->type != TT_FLOW_MAP_END)
-				throw MapEndNotFound();
 		}
 	}
 
@@ -148,4 +163,34 @@ namespace YAML
 		if(m_data.empty())
 			out << std::endl;
 	}
+
+	int Map::Compare(Content *pContent)
+	{
+		return -pContent->Compare(this);
+	}
+
+	int Map::Compare(Map *pMap)
+	{
+		node_map::const_iterator it = m_data.begin(), jt = pMap->m_data.begin();
+		while(1) {
+			if(it == m_data.end()) {
+				if(jt == pMap->m_data.end())
+					return 0;
+				else
+					return -1;
+			}
+			if(jt == pMap->m_data.end())
+				return 1;
+
+			int cmp = it->first->Compare(*jt->first);
+			if(cmp != 0)
+				return cmp;
+
+			cmp = it->second->Compare(*jt->second);
+			if(cmp != 0)
+				return cmp;
+		}
+
+		return 0;
+	}
 }

map.h

@@ -14,17 +14,23 @@ namespace YAML
 		virtual ~Map();
 
 		void Clear();
-		virtual bool GetBegin(std::map <Node *, Node *>::const_iterator& it) const;
-		virtual bool GetEnd(std::map <Node *, Node *>::const_iterator& it) const;
+		virtual bool GetBegin(std::map <Node *, Node *, ltnode>::const_iterator& it) const;
+		virtual bool GetEnd(std::map <Node *, Node *, ltnode>::const_iterator& it) const;
 		virtual void Parse(Scanner *pScanner, const ParserState& state);
 		virtual void Write(std::ostream& out, int indent, bool startedLine, bool onlyOneCharOnLine);
 
+		// ordering
+		virtual int Compare(Content *pContent);
+		virtual int Compare(Scalar *pScalar) { return 1; }
+		virtual int Compare(Sequence *pSeq) { return 1; }
+		virtual int Compare(Map *pMap);
+
 	private:
 		void ParseBlock(Scanner *pScanner, const ParserState& state);
 		void ParseFlow(Scanner *pScanner, const ParserState& state);
 
 	protected:
-		typedef std::map <Node *, Node *> node_map;
+		typedef std::map <Node *, Node *, ltnode> node_map;
 		node_map m_data;
 	};
 }

node.cpp

@@ -9,6 +9,12 @@
 
 namespace YAML
 {
+	// the ordering!
+	bool ltnode::operator ()(const Node *pNode1, const Node *pNode2) const
+	{
+		return *pNode1 < *pNode2;
+	}
+
 	Node::Node(): m_pContent(0), m_alias(false)
 	{
 	}
@@ -150,7 +156,7 @@ namespace YAML
 		if(m_pContent->GetBegin(seqIter))
 			return Iterator(seqIter);
 
-		std::map <Node *, Node *>::const_iterator mapIter;
+		std::map <Node *, Node *, ltnode>::const_iterator mapIter;
 		if(m_pContent->GetBegin(mapIter))
 			return Iterator(mapIter);
 
@@ -168,7 +174,7 @@ namespace YAML
 		if(m_pContent->GetEnd(seqIter))
 			return Iterator(seqIter);
 
-		std::map <Node *, Node *>::const_iterator mapIter;
+		std::map <Node *, Node *, ltnode>::const_iterator mapIter;
 		if(m_pContent->GetEnd(mapIter))
 			return Iterator(mapIter);
 
@@ -274,4 +280,24 @@ namespace YAML
 		node.Write(out, 0, false, false);
 		return out;
 	}
+
+	int Node::Compare(const Node& rhs) const
+	{
+		// Step 1: no content is the smallest
+		if(!m_pContent) {
+			if(rhs.m_pContent)
+				return -1;
+			else
+				return 0;
+		}
+		if(!rhs.m_pContent)
+			return 1;
+
+		return m_pContent->Compare(rhs.m_pContent);
+	}
+
+	bool operator < (const Node& n1, const Node& n2)
+	{
+		return n1.Compare(n2) < 0;
+	}
 }

node.h

@@ -6,6 +6,7 @@
 #include <map>
 #include "parserstate.h"
 #include "exceptions.h"
+#include "ltnode.h"
 
 namespace YAML
 {
@@ -20,7 +21,7 @@ namespace YAML
 		public:
 			Iterator();
 			Iterator(std::vector <Node *>::const_iterator it);
-			Iterator(std::map <Node *, Node *>::const_iterator it);
+			Iterator(std::map <Node *, Node *, ltnode>::const_iterator it);
 			~Iterator();
 
 			friend bool operator == (const Iterator& it, const Iterator& jt);
@@ -37,7 +38,7 @@ namespace YAML
 			ITER_TYPE type;
 
 			std::vector <Node *>::const_iterator seqIter;
-			std::map <Node *, Node *>::const_iterator mapIter;
+			std::map <Node *, Node *, ltnode>::const_iterator mapIter;
 		};
 
 	public:
@@ -95,6 +96,10 @@ namespace YAML
 		// insertion
 		friend std::ostream& operator << (std::ostream& out, const Node& node);
 
+		// ordering
+		int Compare(const Node& rhs) const;
+		friend bool operator < (const Node& n1, const Node& n2);
+
 	private:
 		void ParseHeader(Scanner *pScanner, const ParserState& state);
 		void ParseTag(Scanner *pScanner, const ParserState& state);

scalar.cpp

@@ -88,4 +88,19 @@ namespace YAML
 		if(!data)
 			throw InvalidScalar();
 	}
+
+	int Scalar::Compare(Content *pContent)
+	{
+		return -pContent->Compare(this);
+	}
+
+	int Scalar::Compare(Scalar *pScalar)
+	{
+		if(m_data < pScalar->m_data)
+			return -1;
+		else if(m_data > pScalar->m_data)
+			return 1;
+		else
+			return 0;
+	}
 }

scalar.h

@@ -23,6 +23,12 @@ namespace YAML
 		virtual void Read(double& d);
 		virtual void Read(char& c);
 
+		// ordering
+		virtual int Compare(Content *pContent);
+		virtual int Compare(Scalar *pScalar);
+		virtual int Compare(Sequence *pSeq) { return -1; }
+		virtual int Compare(Map *pMap) { return -1; }
+
 	protected:
 		std::string m_data;
 	};

sequence.cpp

@@ -151,4 +151,26 @@ namespace YAML
 		if(m_data.empty())
 			out << std::endl;
 	}
+
+	int Sequence::Compare(Content *pContent)
+	{
+		return -pContent->Compare(this);
+	}
+
+	int Sequence::Compare(Sequence *pSeq)
+	{
+		unsigned n = m_data.size(), m = pSeq->m_data.size();
+		if(n < m)
+			return -1;
+		else if(n > m)
+			return 1;
+
+		for(unsigned i=0;i<n;i++) {
+			int cmp = m_data[i]->Compare(*pSeq->m_data[i]);
+			if(cmp != 0)
+				return cmp;
+		}
+
+		return 0;
+	}
 }

sequence.h

@@ -22,6 +22,12 @@ namespace YAML
 		virtual void Parse(Scanner *pScanner, const ParserState& state);
 		virtual void Write(std::ostream& out, int indent, bool startedLine, bool onlyOneCharOnLine);
 
+		// ordering
+		virtual int Compare(Content *pContent);
+		virtual int Compare(Scalar *pScalar) { return 1; }
+		virtual int Compare(Sequence *pSeq);
+		virtual int Compare(Map *pMap) { return -1; }
+
 	private:
 		void ParseBlock(Scanner *pScanner, const ParserState& state);
 		void ParseImplicit(Scanner *pScanner, const ParserState& state);

test.yaml

-literal: |
-  Here's a literal scalar.
-  That's a newline.
-  
+abeginning: value
+zend: value
+middle: value
\ No newline at end of file
-  Let's go...
-folded: >
-  Here's a folded scalar that
-  wraps over to a newline.
-  
-  Let's go...
-regular: Here's a regular
-   scalar that keeps
-   on wrapping...
-   
-   
-   Let's go!
-and last key: so it doesn't go bonkers
\ No newline at end of file

tests.cpp

@@ -15,6 +15,7 @@ namespace YAML
 			std::vector <std::string> files;
 			files.push_back("tests/simple.yaml");
 			files.push_back("tests/mixed.yaml");
+			files.push_back("tests/scalars.yaml");
 
 			bool passed = true;
 			for(unsigned i=0;i<files.size();i++) {
@@ -63,7 +64,7 @@ namespace YAML
 				if(firstTry == secondTry)
 					return true;
 
-				std::ofstream fout("out.yaml");
+				std::ofstream fout("tests/out.yaml");
 				fout << "---\n";
 				fout << firstTry << std::endl;
 				fout << "---\n";

tests/scalars.yaml

+- normal scalar, but
+  over several lines
+- |
+  literal scalar - so we can draw ASCII:
+  
+         -   -
+        |  -   |
+         ------
+- >
+  and a folded scalar... so we
+  can just keep writing various
+  things. And if we want to keep indentation:
+  
+    we just indent a little
+    see, this stays indented
+- >-
+  Here's a folded scalar
+  that gets chomped.
+- |-
+  And here's a literal scalar
+  that gets chomped.
+- >2
+       Here's a folded scalar
+  that starts with some indentation.
\ No newline at end of file

yaml-reader.vcproj

@@ -302,6 +302,10 @@
 					RelativePath=".\content.h"
 					>
 				</File>
+				<File
+					RelativePath=".\ltnode.h"
+					>
+				</File>
 				<File
 					RelativePath=".\map.h"
 					>