Minor polishing for Java bindings and first draft of JEXL datamodel

31 files changed, 122 insertions, 102 deletions

diff --git a/src/uscxml/Interpreter.cpp b/src/uscxml/Interpreter.cpp
index 05fb1fc..a050401 100644
--- a/src/uscxml/Interpreter.cpp
+++ b/src/uscxml/Interpreter.cpp
@@ -192,8 +192,8 @@ void Interpreter::reset() {
 	return _impl->reset();
 }
 
-InterpreterState Interpreter::step(bool blocking) {
-	return _impl->step(blocking);
+InterpreterState Interpreter::step(size_t blockMs) {
+	return _impl->step(blockMs);
 };
 
 void Interpreter::cancel() {
@@ -239,7 +239,7 @@ static void printNodeSet(const std::list<XERCESC_NS::DOMElement*> nodes) {
 	}
 }
 #endif
-    
+
 void StateTransitionMonitor::beforeTakingTransition(const XERCESC_NS::DOMElement* transition) {
 	std::lock_guard<std::recursive_mutex> lock(_mutex);
 	std::cerr << "Transition: " << uscxml::DOMUtils::xPathForNode(transition) << std::endl;
diff --git a/src/uscxml/Interpreter.h b/src/uscxml/Interpreter.h
index 1596914..bab0ebc 100644
--- a/src/uscxml/Interpreter.h
+++ b/src/uscxml/Interpreter.h
@@ -154,13 +154,19 @@ public:
 	PIMPL_OPERATORS(Interpreter);
 
 	/**
-	 * Perform a single microstep and return.
-	 * @param blocking Whether or not to block the thread when waiting for events
-	 * @return The new state of the interpreter object.
+	 * Advance the state-machine by a single microstep and return.
+	 *
+	 * This is the central function to drive the state machine. Calling step()
+	 * will perform one *microstep* and return the current state of the
+	 * interpreter. Here, the state is not to be confused with the interpreter's
+	 * configuration.
 	 *
-	 * @todo Have Interpreter::step() take a duration to block
+	 * \snippet test-snippets.cpp Performing a microstep
+	 *
+	 * @param blockMs The maximum duration in milli-seconds to wait for an event to become available.
+	 * @return The new state of the interpreter object.
 	 */
-	InterpreterState step(bool blocking = true);
+	InterpreterState step(size_t blockMs = std::numeric_limits<size_t>::max());
 
 	/**
 	 * Unblock and mark for finalize.
@@ -177,14 +183,14 @@ public:
 	 * @return A list of XML elements of the active states.
 	 */
 	std::list<XERCESC_NS::DOMElement*> getConfiguration();
-	
+
 	/**
 	 * Determine whether the state with the given `id` is in the active configuration.
 	 * @param id An identifier for a state from the SCXML document.
 	 * @return Whether the interpreter is in state `id`.
 	 */
 	bool isInState(const std::string& stateId);
-	
+
 	/**
 	 * The current state of the interpreter, not to be confused with its configuration.
 	 * @return The current state of the interpreter object.
@@ -202,12 +208,12 @@ public:
 	 * @event An event to be enqueued
 	 */
 	void receive(const Event& event);
-	
+
 	/**
 	 * Adapt the constituting components for a SCXML interpreter.
 	 */
 	void setActionLanguage(ActionLanguage actionLanguage);
-	
+
 	/**
 	 * Attach a monitor to make more details of the interpreter observable.
 	 */
diff --git a/src/uscxml/debug/InterpreterIssue.h b/src/uscxml/debug/InterpreterIssue.h
index c807acc..7eede09 100644
--- a/src/uscxml/debug/InterpreterIssue.h
+++ b/src/uscxml/debug/InterpreterIssue.h
@@ -29,7 +29,7 @@
 
 // forward declare
 namespace XERCESC_NS {
-    class DOMNode;
+class DOMNode;
 }
 
 namespace uscxml {
@@ -54,10 +54,10 @@ public:
 	IssueSeverity severity; ///< Severity of the issue
 	std::string specRef; ///< If applicable, the violated section from the standard
 
-    /**
-     * Constructor is solely used to report issues at runtime.
-     */
-    InterpreterIssue(const std::string& msg, XERCESC_NS::DOMNode* node, IssueSeverity severity, const std::string& specRef = "");
+	/**
+	 * Constructor is solely used to report issues at runtime.
+	 */
+	InterpreterIssue(const std::string& msg, XERCESC_NS::DOMNode* node, IssueSeverity severity, const std::string& specRef = "");
 
 private:
 
diff --git a/src/uscxml/interpreter/BasicEventQueue.cpp b/src/uscxml/interpreter/BasicEventQueue.cpp
index 5d3fa2d..ee2346d 100644
--- a/src/uscxml/interpreter/BasicEventQueue.cpp
+++ b/src/uscxml/interpreter/BasicEventQueue.cpp
@@ -31,13 +31,20 @@ BasicEventQueue::BasicEventQueue() {
 BasicEventQueue::~BasicEventQueue() {
 }
 
-Event BasicEventQueue::dequeue(bool blocking) {
+Event BasicEventQueue::dequeue(size_t blockMs) {
 	std::lock_guard<std::recursive_mutex> lock(_mutex);
-	if (blocking) {
-		while (_queue.empty()) {
-			_cond.wait(_mutex);
+
+	if (blockMs > 0) {
+		// block for given milliseconds or until queue is filled
+		std::chrono::time_point<std::chrono::system_clock> end, now;
+		now = std::chrono::system_clock::now();
+		end = now + std::chrono::milliseconds(blockMs);
+
+		while (std::chrono::system_clock::now() < end && _queue.empty()) {
+			_cond.wait_for(_mutex, std::chrono::system_clock::now() - end);
 		}
 	}
+
 	if (_queue.size() > 0) {
 		Event event = _queue.front();
 		_queue.pop_front();
diff --git a/src/uscxml/interpreter/BasicEventQueue.h b/src/uscxml/interpreter/BasicEventQueue.h
index cfb2b5d..15a1c3c 100644
--- a/src/uscxml/interpreter/BasicEventQueue.h
+++ b/src/uscxml/interpreter/BasicEventQueue.h
@@ -42,7 +42,7 @@ class USCXML_API BasicEventQueue : public EventQueueImpl {
 public:
 	BasicEventQueue();
 	virtual ~BasicEventQueue();
-	virtual Event dequeue(bool blocking);
+	virtual Event dequeue(size_t blockMs);
 	virtual void enqueue(const Event& event);
 
 protected:
@@ -62,8 +62,8 @@ public:
 	virtual void enqueueDelayed(const Event& event, size_t delayMs, const std::string& eventUUID);
 	virtual void cancelDelayed(const std::string& eventId);
 	virtual void cancelAllDelayed();
-	virtual Event dequeue(bool blocking) {
-		return BasicEventQueue::dequeue(blocking);
+	virtual Event dequeue(size_t blockMs) {
+		return BasicEventQueue::dequeue(blockMs);
 	}
 	virtual void enqueue(const Event& event) {
 		return BasicEventQueue::enqueue(event);
diff --git a/src/uscxml/interpreter/ContentExecutor.h b/src/uscxml/interpreter/ContentExecutor.h
index 64f5a95..be0de78 100644
--- a/src/uscxml/interpreter/ContentExecutor.h
+++ b/src/uscxml/interpreter/ContentExecutor.h
@@ -28,7 +28,7 @@
 
 // forward declare
 namespace XERCESC_NS {
- class DOMElement;
+class DOMElement;
 }
 
 namespace uscxml {
diff --git a/src/uscxml/interpreter/EventQueue.cpp b/src/uscxml/interpreter/EventQueue.cpp
index 9b9fa88..c460e02 100644
--- a/src/uscxml/interpreter/EventQueue.cpp
+++ b/src/uscxml/interpreter/EventQueue.cpp
@@ -32,8 +32,8 @@
 
 namespace uscxml {
 
-Event EventQueue::dequeue(bool blocking) {
-	return _impl->dequeue(blocking);
+Event EventQueue::dequeue(size_t blockMs) {
+	return _impl->dequeue(blockMs);
 }
 void EventQueue::enqueue(const Event& event) {
 	return _impl->enqueue(event);
diff --git a/src/uscxml/interpreter/EventQueue.h b/src/uscxml/interpreter/EventQueue.h
index 4409b72..1e8b018 100644
--- a/src/uscxml/interpreter/EventQueue.h
+++ b/src/uscxml/interpreter/EventQueue.h
@@ -36,7 +36,7 @@ class USCXML_API EventQueue {
 public:
 	PIMPL_OPERATORS(EventQueue);
 
-	virtual Event dequeue(bool blocking);
+	virtual Event dequeue(size_t blockMs);
 	virtual void enqueue(const Event& event);
 
 protected:
diff --git a/src/uscxml/interpreter/EventQueueImpl.h b/src/uscxml/interpreter/EventQueueImpl.h
index 1cafd4d..1ccd3f1 100644
--- a/src/uscxml/interpreter/EventQueueImpl.h
+++ b/src/uscxml/interpreter/EventQueueImpl.h
@@ -40,7 +40,7 @@ namespace uscxml {
  */
 class USCXML_API EventQueueImpl {
 public:
-	virtual Event dequeue(bool blocking) = 0;
+	virtual Event dequeue(size_t blockMs) = 0;
 	virtual void enqueue(const Event& event) = 0;
 };
 
diff --git a/src/uscxml/interpreter/FastMicroStep.cpp b/src/uscxml/interpreter/FastMicroStep.cpp
index bf58f7b..3ad5515 100644
--- a/src/uscxml/interpreter/FastMicroStep.cpp
+++ b/src/uscxml/interpreter/FastMicroStep.cpp
@@ -290,23 +290,23 @@ void FastMicroStep::init(XERCESC_NS::DOMElement* scxml) {
 		if (parent && parent->getNodeType() == DOMNode::ELEMENT_NODE) {
 			State* uscxmlState = (State*)parent->getUserData(X("uscxmlState"));
 			// parent maybe a content element
-            if (uscxmlState != NULL) {
-                _states[i]->parent = uscxmlState->documentOrder;
-            }
+			if (uscxmlState != NULL) {
+				_states[i]->parent = uscxmlState->documentOrder;
+			}
 		}
 
 		while(parent && parent->getNodeType() == DOMNode::ELEMENT_NODE) {
 			State* uscxmlState = (State*)parent->getUserData(X("uscxmlState"));
 
-            if (uscxmlState == NULL)
-                break;
+			if (uscxmlState == NULL)
+				break;
 
-            // ancestors
-            BIT_SET_AT(uscxmlState->documentOrder, _states[i]->ancestors);
+			// ancestors
+			BIT_SET_AT(uscxmlState->documentOrder, _states[i]->ancestors);
 
-            // children
-            BIT_SET_AT(i, uscxmlState->children);
-            parent = parent->getParentNode();
+			// children
+			BIT_SET_AT(i, uscxmlState->children);
+			parent = parent->getParentNode();
 		}
 	}
 
@@ -403,7 +403,7 @@ void FastMicroStep::markAsCancelled() {
 	_isCancelled = true;
 }
 
-InterpreterState FastMicroStep::step(bool blocking) {
+InterpreterState FastMicroStep::step(size_t blockMs) {
 	if (!_isInitialized) {
 		init(_scxml);
 		return USCXML_INITIALIZED;
@@ -517,7 +517,7 @@ InterpreterState FastMicroStep::step(bool blocking) {
 		_flags |= USCXML_CTX_STABLE;
 	}
 
-	if ((_event = _callbacks->dequeueExternal(blocking))) {
+	if ((_event = _callbacks->dequeueExternal(blockMs))) {
 		USCXML_MONITOR_CALLBACK1(_callbacks->getMonitor(), beforeProcessingEvent, _event);
 		goto SELECT_TRANSITIONS;
 	}
diff --git a/src/uscxml/interpreter/FastMicroStep.h b/src/uscxml/interpreter/FastMicroStep.h
index 3789af9..023bb8f 100644
--- a/src/uscxml/interpreter/FastMicroStep.h
+++ b/src/uscxml/interpreter/FastMicroStep.h
@@ -42,7 +42,7 @@ public:
 	FastMicroStep(MicroStepCallbacks* callbacks);
 	virtual ~FastMicroStep();
 
-	virtual InterpreterState step(bool blocking);
+	virtual InterpreterState step(size_t blockMs);
 	virtual void reset();
 	virtual bool isInState(const std::string& stateId);
 	virtual std::list<XERCESC_NS::DOMElement*> getConfiguration();
diff --git a/src/uscxml/interpreter/InterpreterImpl.cpp b/src/uscxml/interpreter/InterpreterImpl.cpp
index 880afbc..3383411 100644
--- a/src/uscxml/interpreter/InterpreterImpl.cpp
+++ b/src/uscxml/interpreter/InterpreterImpl.cpp
@@ -259,8 +259,8 @@ bool InterpreterImpl::checkValidSendType(const std::string& type, const std::str
 	return true;
 }
 
-Event InterpreterImpl::dequeueExternal(bool blocking) {
-	_currEvent = _externalQueue.dequeue(blocking);
+Event InterpreterImpl::dequeueExternal(size_t blockMs) {
+	_currEvent = _externalQueue.dequeue(blockMs);
 	if (_currEvent) {
 		_dataModel.setEvent(_currEvent);
 
diff --git a/src/uscxml/interpreter/InterpreterImpl.h b/src/uscxml/interpreter/InterpreterImpl.h
index e1abf9b..e693bbf 100644
--- a/src/uscxml/interpreter/InterpreterImpl.h
+++ b/src/uscxml/interpreter/InterpreterImpl.h
@@ -65,12 +65,12 @@ public:
 	void cloneFrom(InterpreterImpl* other);
 	void cloneFrom(std::shared_ptr<InterpreterImpl> other);
 
-	virtual InterpreterState step(bool blocking) {
+	virtual InterpreterState step(size_t blockMs) {
 		if (!_isInitialized) {
 			init();
 			_state = USCXML_INITIALIZED;
 		} else {
-			_state = _microStepper.step(blocking);
+			_state = _microStepper.step(blockMs);
 		}
 		return _state;
 	}
@@ -107,7 +107,7 @@ public:
 			_dataModel.setEvent(_currEvent);
 		return _currEvent;
 	}
-	virtual Event dequeueExternal(bool blocking);
+	virtual Event dequeueExternal(size_t blockMs);
 	virtual bool isTrue(const std::string& expr);
 
 	virtual void raiseDoneEvent(XERCESC_NS::DOMElement* state, XERCESC_NS::DOMElement* doneData) {
diff --git a/src/uscxml/interpreter/InterpreterMonitor.h b/src/uscxml/interpreter/InterpreterMonitor.h
index 901e1eb..8dac445 100644
--- a/src/uscxml/interpreter/InterpreterMonitor.h
+++ b/src/uscxml/interpreter/InterpreterMonitor.h
@@ -20,6 +20,7 @@
 #ifndef INTERPRETERMONITOR_H_D3F21429
 #define INTERPRETERMONITOR_H_D3F21429
 
+#include "uscxml/config.h"
 #include "uscxml/Common.h"
 #include "uscxml/messages/Event.h"
 #include "uscxml/debug/InterpreterIssue.h"
@@ -41,6 +42,11 @@ if (callback) { callback->function(arg1); }
 #define USCXML_MONITOR_CALLBACK2(callback, function, arg1, arg2) \
 if (callback) { callback->function(arg1, arg2); }
 
+// forward declare
+namespace XERCESC_NS {
+    class DOMElement;
+}
+
 namespace uscxml {
 
 class USCXML_API InterpreterMonitor {
diff --git a/src/uscxml/interpreter/InterpreterState.h b/src/uscxml/interpreter/InterpreterState.h
index a4741ed..5acbd74 100644
--- a/src/uscxml/interpreter/InterpreterState.h
+++ b/src/uscxml/interpreter/InterpreterState.h
@@ -27,8 +27,7 @@
 namespace uscxml {
 
 enum InterpreterState {
-	USCXML_FINISHED       = -2,  ///< machine reached a final configuration and is done
-	USCXML_INTERRUPTED    = -1,  ///< machine received the empty event on the external queue
+	USCXML_FINISHED       = -1,  ///< machine reached a final configuration and is done
 	USCXML_UNDEF          = 0,   ///< not an actual state
 	USCXML_IDLE           = 1,   ///< stable configuration and queues empty
 	USCXML_INITIALIZED    = 2,   ///< DOM is setup and all external components instantiated
diff --git a/src/uscxml/interpreter/MicroStep.cpp b/src/uscxml/interpreter/MicroStep.cpp
index aa75c91..2876be5 100644
--- a/src/uscxml/interpreter/MicroStep.cpp
+++ b/src/uscxml/interpreter/MicroStep.cpp
@@ -22,8 +22,8 @@
 
 namespace uscxml {
 
-InterpreterState MicroStep::step(bool blocking) {
-	return _impl->step(blocking);
+InterpreterState MicroStep::step(size_t blockMs) {
+	return _impl->step(blockMs);
 }
 void MicroStep::reset() {
 	return _impl->reset();
diff --git a/src/uscxml/interpreter/MicroStep.h b/src/uscxml/interpreter/MicroStep.h
index c20e994..a8ea4f0 100644
--- a/src/uscxml/interpreter/MicroStep.h
+++ b/src/uscxml/interpreter/MicroStep.h
@@ -33,7 +33,7 @@
 
 // forward declare
 namespace XERCESC_NS {
-    class DOMElement;
+class DOMElement;
 }
 
 namespace uscxml {
@@ -48,7 +48,7 @@ class USCXML_API MicroStep {
 public:
 	PIMPL_OPERATORS(MicroStep);
 
-	virtual InterpreterState step(bool blocking);
+	virtual InterpreterState step(size_t blockMs);
 	virtual void reset();
 	virtual bool isInState(const std::string& stateId);
 
diff --git a/src/uscxml/interpreter/MicroStepImpl.h b/src/uscxml/interpreter/MicroStepImpl.h
index e4cde5d..be9d974 100644
--- a/src/uscxml/interpreter/MicroStepImpl.h
+++ b/src/uscxml/interpreter/MicroStepImpl.h
@@ -41,7 +41,7 @@ class USCXML_API MicroStepCallbacks {
 public:
 	/** Event Queues / Matching */
 	virtual Event dequeueInternal() = 0;
-	virtual Event dequeueExternal(bool blocking) = 0;
+	virtual Event dequeueExternal(size_t blockMs) = 0;
 	virtual bool isMatched(const Event& event, const std::string& eventDesc) = 0;
 	virtual void raiseDoneEvent(XERCESC_NS::DOMElement* state, XERCESC_NS::DOMElement* doneData) = 0;
 
@@ -73,7 +73,7 @@ public:
 
 	MicroStepImpl(MicroStepCallbacks* callbacks) : _callbacks(callbacks) {}
 
-	virtual InterpreterState step(bool blocking) = 0;
+	virtual InterpreterState step(size_t blockMs) = 0;
 	virtual void reset() = 0; ///< Reset state machine
 	virtual bool isInState(const std::string& stateId) = 0;
 	virtual std::list<XERCESC_NS::DOMElement*> getConfiguration() = 0;
diff --git a/src/uscxml/messages/Data.h b/src/uscxml/messages/Data.h
index 6ab3bec..73640f0 100644
--- a/src/uscxml/messages/Data.h
+++ b/src/uscxml/messages/Data.h
@@ -33,8 +33,8 @@
 
 // forward declare
 namespace XERCESC_NS {
-	class DOMDocument;
-	class DOMNode;
+class DOMDocument;
+class DOMNode;
 }
 
 namespace uscxml {
diff --git a/src/uscxml/plugins/DataModel.h b/src/uscxml/plugins/DataModel.h
index 03e557c..7716ad7 100644
--- a/src/uscxml/plugins/DataModel.h
+++ b/src/uscxml/plugins/DataModel.h
@@ -43,7 +43,7 @@ public:
 	PIMPL_OPERATORS(DataModel);
 
 	/// @copydoc DataModelImpl::getNames()
-	virtual std::list<std::string> getNames();	
+	virtual std::list<std::string> getNames();
 	/// @copydoc DataModelImpl::isValidSyntax()
 	virtual bool isValidSyntax(const std::string& expr);
 
diff --git a/src/uscxml/plugins/DataModelImpl.h b/src/uscxml/plugins/DataModelImpl.h
index c3f5390..403a213 100644
--- a/src/uscxml/plugins/DataModelImpl.h
+++ b/src/uscxml/plugins/DataModelImpl.h
@@ -69,11 +69,11 @@ public:
 class USCXML_API DataModelImpl {
 public:
 	virtual ~DataModelImpl() {}
-	
+
 	/**
 	 * The Factory wants to instantiate a new instance.
-	 * This function will have to initialize the object. The actual constructor 
-	 * is called from within here. The only one who calls the constructor directly 
+	 * This function will have to initialize the object. The actual constructor
+	 * is called from within here. The only one who calls the constructor directly
 	 * is the Factory for the prototype object.
 	 *
 	 * @param callbacks The callbacks available to the datamodel
@@ -87,7 +87,7 @@ public:
 	virtual std::list<std::string> getNames() = 0;
 
 	/**
-	 * Determine whether a given string constitutes valid syntax in the 
+	 * Determine whether a given string constitutes valid syntax in the
 	 * data-model's language.
 	 * @param expr A string, supposedly containing an expression of the data-model.
 	 * @return Whether expr is in L(DM).
@@ -95,7 +95,7 @@ public:
 	virtual bool isValidSyntax(const std::string& expr) {
 		return true; // overwrite when datamodel supports it
 	}
-	
+
 	/**
 	 * Set the given event as `_event` in the data-model's global scope.
 	 * @param event The event as it was dequeued from either the internal or external queue.
@@ -104,7 +104,7 @@ public:
 
 	/**
 	 * Experimental extension to have dynamic content in string literals.
-	 * This function was used to replace ${foo} expressions on the data-model, 
+	 * This function was used to replace ${foo} expressions on the data-model,
 	 * e.g. in text nodes. It will eventually make a reappearance I guess.
 	 * @param content The string with tokens to replace.
 	 * @return How many occurences where replaced.
@@ -116,8 +116,8 @@ public:
 	 * @param expr Anything that possibly evaluates to an enumerable object.
 	 * @return The number of items in the enumerable object.
 	 */
-	virtual uint32_t getLength(const std::string& expr) = 0;
-	
+    virtual uint32_t getLength(const std::string& expr) = 0;
+
 	/**
 	 * Set a given item to the object at a given index for one iteration.
 	 * @param item A variable or location to assign the current object to.
@@ -143,7 +143,7 @@ public:
 	 * @return An evaluated structure representing the given compound or literal.
 	 */
 	virtual Data evalAsData(const std::string& content) = 0;
-	
+
 	/**
 	 * Evaluate a given expression as a boolean.
 	 * This function is a subset of evalAsData() but saves on creating and copying a Data object.
@@ -162,28 +162,28 @@ public:
 	/**
 	 * Assign a data object to a location in the data-model.
 	 * There are different occurences in the SCXML IRP tests, e.g.
-\verbatim
-test147:
-  <data id="Var1" expr="0"/>
-
-test150:
-  <data id="Var3">
-    [1,2,3]
-  </data>
-
-test277:
-  <data id="Var1" expr="return"/>
-\endverbatim
+	\verbatim
+	test147:
+	<data id="Var1" expr="0"/>
+
+	test150:
+	<data id="Var3">
+	[1,2,3]
+	</data>
+
+	test277:
+	<data id="Var1" expr="return"/>
+	\endverbatim
 	 * @param location A variable or locatio to assign to.
 	 * @param data The Data object with the respective data.
 	 */
 	virtual void assign(const std::string& location, const Data& data) = 0;
-	
+
 	/**
 	 * Initialize a variable / location in the data-model with a given data object.
-	 * This is, semantically, very close to assign() but does not assume the 
+	 * This is, semantically, very close to assign() but does not assume the
 	 * location to be declared first.
-	 * 
+	 *
 	 * @param location A variable or locatio to assign to.
 	 * @param data The Data object with the respective data.
 	 */
@@ -194,10 +194,10 @@ test277:
 	 * @todo This is currently unsupported
 	 */
 	virtual void addExtension(DataModelExtension* ext);
-	
+
 	/**
 	 * Concat the given terms into a conjunctive form.
-	 * @todo This is required to automatically transform a state-chart into a 
+	 * @todo This is required to automatically transform a state-chart into a
 	 * state-machine. Actual transformation is still only available in legacy though.
 	 */
 	virtual std::string andExpressions(std::list<std::string>) {
diff --git a/src/uscxml/plugins/EventHandler.h b/src/uscxml/plugins/EventHandler.h
index e08b1ad..436f878 100644
--- a/src/uscxml/plugins/EventHandler.h
+++ b/src/uscxml/plugins/EventHandler.h
@@ -47,7 +47,7 @@ public:
 	 * Return a list of names for types we implement.
 	 */
 	virtual std::list<std::string> getNames() = 0;
-	
+
 	/**
 	 * Export a Data object for the `_x['name']` data-model namespace
 	 * @return An object to be represented at `_x['name']`
diff --git a/src/uscxml/plugins/ExecutableContent.h b/src/uscxml/plugins/ExecutableContent.h
index 14c1d5d..5fb2ac6 100644
--- a/src/uscxml/plugins/ExecutableContent.h
+++ b/src/uscxml/plugins/ExecutableContent.h
@@ -29,7 +29,7 @@
 
 // forward declare
 namespace XERCESC_NS {
-    class DOMElement;
+class DOMElement;
 }
 
 namespace uscxml {
@@ -50,7 +50,7 @@ public:
 	void enterElement(XERCESC_NS::DOMElement* node);
 	void exitElement(XERCESC_NS::DOMElement* node);
 	bool processChildren();
-	
+
 protected:
 	std::shared_ptr<ExecutableContentImpl> _impl;
 
diff --git a/src/uscxml/plugins/IOProcessor.h b/src/uscxml/plugins/IOProcessor.h
index 558edfa..c2b6e30 100644
--- a/src/uscxml/plugins/IOProcessor.h
+++ b/src/uscxml/plugins/IOProcessor.h
@@ -41,7 +41,7 @@ public:
 
 	/// @copydoc IOProcessorImpl::eventFromSCXML
 	virtual void eventFromSCXML(const std::string& target, const Event& event);
-	
+
 	/// @copydoc IOProcessorImpl::isValidTarget
 	virtual bool isValidTarget(const std::string& target);
 
diff --git a/src/uscxml/plugins/IOProcessorImpl.h b/src/uscxml/plugins/IOProcessorImpl.h
index 0e5b44a..bd28406 100644
--- a/src/uscxml/plugins/IOProcessorImpl.h
+++ b/src/uscxml/plugins/IOProcessorImpl.h
@@ -24,6 +24,7 @@
 #include "uscxml/Common.h"
 #include "uscxml/plugins/EventHandler.h"
 #include "uscxml/messages/Event.h"
+#include "uscxml/interpreter/InterpreterImpl.h"
 
 namespace uscxml {
 
@@ -48,7 +49,7 @@ public:
 	 * @param event The event to deliver.
 	 */
 	virtual void eventFromSCXML(const std::string& target, const Event& event) = 0;
-	
+
 	/**
 	 * Determine whether the given target is a valid destination for events.
 	 * @param target A target where the Interpreter wants to deliver Event%s to.
@@ -63,7 +64,7 @@ protected:
 	 * @param type The type of this I/O Processor for `event.origintype`.
 	 * @param origin The origin of this I/O Processor for `event.origin`.
 	 * @param internal If the event is to be delivered to the Interpreter's internal queue instead.
-	 */	
+	 */
 	void eventToSCXML(Event& event, const std::string& type, const std::string& origin, bool internal = false);
 
 };
diff --git a/src/uscxml/plugins/Invoker.h b/src/uscxml/plugins/Invoker.h
index 33a89d6..f5c55d5 100644
--- a/src/uscxml/plugins/Invoker.h
+++ b/src/uscxml/plugins/Invoker.h
@@ -28,8 +28,8 @@
 #include <xercesc/dom/DOM.hpp>
 
 namespace XERCESC_NS {
-    class DOMDocument;
-    class DOMNode;
+class DOMDocument;
+class DOMNode;
 }
 
 namespace uscxml {
diff --git a/src/uscxml/plugins/InvokerImpl.h b/src/uscxml/plugins/InvokerImpl.h
index d8a3410..7f2e578 100644
--- a/src/uscxml/plugins/InvokerImpl.h
+++ b/src/uscxml/plugins/InvokerImpl.h
@@ -25,6 +25,7 @@
 #include "uscxml/Common.h"
 #include "uscxml/plugins/EventHandler.h"
 #include "uscxml/messages/Event.h"
+#include "uscxml/interpreter/InterpreterImpl.h"
 
 namespace uscxml {
 
@@ -39,7 +40,7 @@ class USCXML_API InvokerImpl : public EventHandlerImpl {
 public:
 	InvokerImpl() : _finalize(NULL) {};
 	virtual ~InvokerImpl() {}
-	
+
 	virtual std::list<std::string> getNames() = 0;
 
 	/**
@@ -72,7 +73,7 @@ public:
 	virtual XERCESC_NS::DOMElement* getFinalize() {
 		return _finalize;
 	}
-	
+
 	/**
 	 * Set the finalize XML element associated with this invoker.
 	 * @param finalize The finalize XMl element.
@@ -80,7 +81,7 @@ public:
 	virtual void setFinalize(XERCESC_NS::DOMElement* finalize) {
 		_finalize = finalize;
 	}
-	
+
 	/**
 	 * Set the invocation identifier as required when returning events.
 	 * @param invokeId The invocation identifier.
@@ -96,7 +97,7 @@ protected:
 	 * @param type The type of this I/O Processor for `event.origintype`.
 	 * @param invokeId The invocation identifier of this invocation for `event.invokeid`.
 	 * @param internal If the event is to be delivered to the Interpreter's internal queue instead.
-	 */	
+	 */
 	void eventToSCXML(Event& event, const std::string& type, const std::string& invokeId, bool internal = false);
 
 	XERCESC_NS::DOMElement* _finalize;
diff --git a/src/uscxml/util/DOM.cpp b/src/uscxml/util/DOM.cpp
index 0e1e9fa..ecf0960 100644
--- a/src/uscxml/util/DOM.cpp
+++ b/src/uscxml/util/DOM.cpp
@@ -194,12 +194,12 @@ bool DOMUtils::isMember(const DOMElement* node,
 	return false;
 }
 
-const DOMNode* DOMUtils::getNearestAncestor(const DOMNode* node, const std::string tagName) {
+const DOMElement* DOMUtils::getNearestAncestor(const DOMNode* node, const std::string tagName) {
 	const DOMNode* parent = node->getParentNode();
 	while(parent) {
 		if (parent->getNodeType() == DOMNode::ELEMENT_NODE &&
 		        iequals(TAGNAME_CAST(parent), tagName)) {
-			return parent;
+			return static_cast<const DOMElement*>(parent);
 		}
 		parent = parent->getParentNode();
 	}
diff --git a/src/uscxml/util/DOM.h b/src/uscxml/util/DOM.h
index 0e8621c..f259ea0 100644
--- a/src/uscxml/util/DOM.h
+++ b/src/uscxml/util/DOM.h
@@ -59,7 +59,7 @@ namespace uscxml {
 class USCXML_API DOMUtils {
 public:
 
-	static const XERCESC_NS::DOMNode* getNearestAncestor(const XERCESC_NS::DOMNode* node, const std::string tagName);
+	static const XERCESC_NS::DOMElement* getNearestAncestor(const XERCESC_NS::DOMNode* node, const std::string tagName);
 	static bool isDescendant(const XERCESC_NS::DOMNode* s1, const XERCESC_NS::DOMNode* s2);
 
 
diff --git a/src/uscxml/util/URL.cpp b/src/uscxml/util/URL.cpp
index 561b9aa..a76c772 100644
--- a/src/uscxml/util/URL.cpp
+++ b/src/uscxml/util/URL.cpp
@@ -144,9 +144,9 @@ URL URLImpl::resolveWithCWD(URLImpl* relative) {
 #if WIN32
 	std::shared_ptr<URLImpl> cwdURL(new URLImpl(std::string(currPath)));
 #else
-    std::shared_ptr<URLImpl> cwdURL(new URLImpl(std::string("file://") + currPath + PATH_SEPERATOR));
+	std::shared_ptr<URLImpl> cwdURL(new URLImpl(std::string("file://") + currPath + PATH_SEPERATOR));
 #endif
-    
+
 	return resolve(relative, cwdURL.get());
 }
 
diff --git a/src/uscxml/util/URL.h b/src/uscxml/util/URL.h
index dba8e3d..8127892 100644
--- a/src/uscxml/util/URL.h
+++ b/src/uscxml/util/URL.h
@@ -191,7 +191,7 @@ protected:
 class USCXML_API URL {
 public:
 	PIMPL_OPERATORS(URL);
-	
+
 	URL(const std::string url) : _impl(new URLImpl(url)) {}
 
 	bool isAbsolute() {