Continued working on scanner.

We're now using exceptions for errors, and scanning/pushing tokens is exception-safe (using a set of "limbo tokens").

document.cpp

@@ -2,6 +2,7 @@
 #include "node.h"
 #include "parser.h"
 #include "scanner.h"
+#include "exceptions.h"
 #include <fstream>
 
 namespace YAML
@@ -32,7 +33,11 @@ namespace YAML
 
 		std::ifstream fin(fileName.c_str());
 		Scanner scanner(fin);
-		scanner.Scan();
+
+		try {
+			scanner.Scan();
+		} catch(const UnknownToken& e) {
+		}
 //		if(!scanner)
 //			return;
 

exceptions.h

+#pragma once
+
+#include <exception>
+
+namespace YAML
+{
+	class Exception: public std::exception {};
+
+	class UnknownToken: public Exception {};
+	class IllegalBlockEntry: public Exception {};
+	class IllegalMapKey: public Exception {};
+	class IllegalMapValue: public Exception {};
+	class IllegalScalar: public Exception {};
+}

scanner.h

@@ -4,6 +4,7 @@
 #include <string>
 #include <queue>
 #include <stack>
+#include <set>
 
 namespace YAML
 {
@@ -12,6 +13,19 @@ namespace YAML
 	namespace Keys
 	{
 		const char Comment = '#';
+		const char FlowSeqStart = '[';
+		const char FlowSeqEnd = ']';
+		const char FlowMapStart = '{';
+		const char FlowMapEnd = '}';
+		const char FlowEntry = ',';
+		const char BlockEntry = '-';
+		const char Key = '?';
+		const char Value = ':';
+		const char Alias = '*';
+		const char Anchor = '&';
+		const char Tag = '!';
+		const char LiteralScalar = '|';
+		const char FoldedScalar = '>';
 	}
 
 	class Scanner
@@ -20,8 +34,10 @@ namespace YAML
 		Scanner(std::istream& in);
 		~Scanner();
 
-		Token *ScanNextToken();
+		void ScanNextToken();
 		void ScanToNextToken();
+		void PushIndentTo(int column, bool sequence);
+		void PopIndentTo(int column);
 
 		void Scan();
 
@@ -36,6 +52,12 @@ namespace YAML
 		bool IsBlank();
 		bool IsDocumentStart();
 		bool IsDocumentEnd();
+		bool IsBlockEntry();
+		bool IsKey();
+		bool IsValue();
+		bool IsPlainScalar();
+
+		template <typename T> void ScanAndEnqueue(T *pToken);
 		template <typename T> T *ScanToken(T *pToken);
 
 	private:
@@ -45,6 +67,7 @@ namespace YAML
 
 		// the output (tokens)
 		std::queue <Token *> m_tokens;
+		std::set <Token *> m_limboTokens;
 
 		// state info
 		bool m_startedStream;

token.h

@@ -3,8 +3,25 @@
 namespace YAML
 {
 	class Token {};
+
 	class StreamStartToken: public Token {};
 	class StreamEndToken: public Token {};
 	class DocumentStartToken: public Token {};
 	class DocumentEndToken: public Token {};
+
+	class BlockSeqStartToken: public Token {};
+	class BlockMapStartToken: public Token {};
+	class BlockEndToken: public Token {};
+	class BlockEntryToken: public Token {};
+
+	class FlowSeqStartToken: public Token {};
+	class FlowMapStartToken: public Token {};
+	class FlowSeqEndToken: public Token {};
+	class FlowMapEndToken: public Token {};
+	class FlowEntryToken: public Token {};
+
+	class KeyToken: public Token {};
+	class ValueToken: public Token {};
+
+	class PlainScalarToken: public Token {};
 }

yaml-reader.vcproj

@@ -212,6 +212,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\exceptions.h"
+				>
+			</File>
+			<File
 				RelativePath=".\map.h"
 				>
 			</File>