Merged r366:387 from the jbeder-event-api branch

src/emitfromevents.cpp

@@ -0,0 +1,106 @@
+#include "emitfromevents.h"
+#include "emitter.h"
+#include "null.h"
+#include <cassert>
+#include <sstream>
+
+namespace {
+	std::string ToString(YAML::anchor_t anchor) {
+		std::stringstream stream;
+		stream << anchor;
+		return stream.str();
+	}
+}
+
+namespace YAML
+{
+	EmitFromEvents::EmitFromEvents(Emitter& emitter): m_emitter(emitter)
+	{
+	}
+	
+	void EmitFromEvents::OnDocumentStart(const Mark&)
+	{
+	}
+	
+	void EmitFromEvents::OnDocumentEnd()
+	{
+	}
+	
+	void EmitFromEvents::OnNull(const std::string& tag, anchor_t anchor)
+	{
+		BeginNode();
+		EmitProps(tag, anchor);
+		if(tag.empty())
+			m_emitter << Null;
+	}
+	
+	void EmitFromEvents::OnAlias(const Mark&, anchor_t anchor)
+	{
+		BeginNode();
+		m_emitter << Alias(ToString(anchor));
+	}
+	
+	void EmitFromEvents::OnScalar(const Mark&, const std::string& tag, anchor_t anchor, const std::string& value)
+	{
+		BeginNode();
+		EmitProps(tag, anchor);
+		m_emitter << value;
+	}
+	
+	void EmitFromEvents::OnSequenceStart(const Mark&, const std::string& tag, anchor_t anchor)
+	{
+		BeginNode();
+		EmitProps(tag, anchor);
+		m_emitter << BeginSeq;
+		m_stateStack.push(State::WaitingForSequenceEntry);
+	}
+	
+	void EmitFromEvents::OnSequenceEnd()
+	{
+		m_emitter << EndSeq;
+		assert(m_stateStack.top() == State::WaitingForSequenceEntry);
+		m_stateStack.pop();
+	}
+	
+	void EmitFromEvents::OnMapStart(const Mark&, const std::string& tag, anchor_t anchor)
+	{
+		BeginNode();
+		EmitProps(tag, anchor);
+		m_emitter << BeginMap;
+		m_stateStack.push(State::WaitingForKey);
+	}
+
+	void EmitFromEvents::OnMapEnd()
+	{
+		m_emitter << EndMap;
+		assert(m_stateStack.top() == State::WaitingForKey);
+		m_stateStack.pop();
+	}
+
+	void EmitFromEvents::BeginNode()
+	{
+		if(m_stateStack.empty())
+			return;
+		
+		switch(m_stateStack.top()) {
+			case State::WaitingForKey:
+				m_emitter << Key;
+				m_stateStack.top() = State::WaitingForValue;
+				break;
+			case State::WaitingForValue:
+				m_emitter << Value;
+				m_stateStack.top() = State::WaitingForKey;
+				break;
+			default:
+				break;
+		}
+	}
+	
+	void EmitFromEvents::EmitProps(const std::string& tag, anchor_t anchor)
+	{
+		if(!tag.empty())
+			m_emitter << VerbatimTag(tag);
+		if(anchor)
+			m_emitter << Anchor(ToString(anchor));
+	}
+}