6 files changed, 31 insertions, 11 deletions

diff --git a/Node.cpp b/Node.cpp
index e837d06..7832d30 100644
--- a/Node.cpp
+++ b/Node.cpp
@@ -30,10 +30,15 @@ void Node::sim() {
 		throw CircuitException("Too few inputs");
 	if (this->max_inputs >= 0 && input_size > max_inputs)
 		throw CircuitException("Too many inputs");
+	
+	// NodeOutput does not have an output itself
+	if (this->output == nullptr) return;
 
 	SignalLevel new_out = this->level();
 
+	// don't propagate if undefined
 	if (new_out == UNDEFINED) return;
+	// don't propagate if unchanged
 	if (this->output->getLevel() == new_out) return;
 
 	this->output->setLevel(new_out);
diff --git a/Node.h b/Node.h
index 46a06e4..f2eb497 100644
--- a/Node.h
+++ b/Node.h
@@ -17,6 +17,7 @@ public:
 	virtual Node * clone() const = 0;
 
 public:
+	//! alias to \p sim() for Observer
 	void update();
 	virtual void addInput(Net *);
 	virtual void setOutput(Net *);
diff --git a/NodeInput.cpp b/NodeInput.cpp
index 41d5352..a106319 100644
--- a/NodeInput.cpp
+++ b/NodeInput.cpp
@@ -5,7 +5,7 @@ NodeInputLow NodeInputLow::instance(NodeInputLow::type);
 NodeInputHigh NodeInputHigh::instance(NodeInputHigh::type);
 
 NodeInput::NodeInput() {
-	this->max_inputs = -1;
+	this->min_inputs = -1;
 	this->max_inputs = 0;
 }
 
diff --git a/NodeOutput.cpp b/NodeOutput.cpp
index a02ba1f..cf1b979 100644
--- a/NodeOutput.cpp
+++ b/NodeOutput.cpp
@@ -1,21 +1,31 @@
 #include "NodeOutput.h"
 #include "Exception.h"
 
-#include "prut.h"
-
 NodeOutput NodeOutput::instance(NodeOutput::type);
 
-NodeOutput::NodeOutput(const char * type) : Node(type) { }
+NodeOutput::NodeOutput(const char * type) : Node(type) { init(); }
 
-void NodeOutput::sim() {
-   if (this->inputs.size() == 0)
-      throw CircuitException("No inputs on probe");
+void NodeOutput::init() {
+	this->min_inputs = 1;
+	this->max_inputs = 1;
+}
 
-	 prutprintf("level: %u", this->inputs[0]->getLevel());
+void NodeOutput::sim() {
+	Node::sim();
+	this->input = this->inputs[0]->getLevel();
 }
 
-NodeOutput::NodeOutput(const NodeOutput * prototype) : Node() { }
+NodeOutput::NodeOutput(const NodeOutput * prototype) : Node() { init(); }
 
 NodeOutput * NodeOutput::clone() const {
 	return new NodeOutput(this);
 }
+
+void NodeOutput::setOutput(Net *) {
+	throw CircuitException("NodeOutput cannot have an output");
+}
+
+SignalLevel NodeOutput::level() {
+	return this->input;
+}
+
diff --git a/NodeOutput.h b/NodeOutput.h
index cd25055..d2319f1 100644
--- a/NodeOutput.h
+++ b/NodeOutput.h
@@ -4,16 +4,20 @@
 
 class NodeOutput : public Node {
 public:
+	NodeOutput();
 	NodeOutput(const NodeOutput * prototype);
 	~NodeOutput() = default;
 	virtual void sim();
-	SignalLevel level() { return UNDEFINED; };
+	virtual SignalLevel level();
 	virtual NodeOutput * clone() const;
+	virtual void setOutput(Net *);
 
 private:
+	virtual void init();
 	NodeOutput(const char * type);
 	constexpr static const char * type = "probe";
 	static NodeOutput instance;
+	SignalLevel input;
 
 public:
 	virtual void accept(NodeVisitor & visitor) { visitor.visit(*this); }
diff --git a/readme.md b/readme.md
index 789010b..57cd870 100644
--- a/readme.md
+++ b/readme.md
@@ -20,7 +20,7 @@ make
 Functions:
 
 - [ ] loop detection (JOSHUA)
-- [ ] final output format (LOEK)
+- [x] final output format (LOEK)
 
 Schoonheid: