Created a Poset template class. It can store the relationships of a partially ordered set, then generate a topological ordering. It will be used to order the type_def declarations in the CGenerator, as they depend on each other in a poset fashion.

include/Poset.h

@@ -0,0 +1,118 @@
+
+#ifndef POSET_H
+#define POSET_H
+
+#include <vector>
+#include <set>
+#include <map>
+#include <queue>
+
+#include <cassert>
+
+#include "util.h"
+
+template <class T>
+class Poset {
+	public:
+		Poset();
+		~Poset();
+		void addRelationship(T first, T second);
+		bool zeroDependencies(T vertex);
+		std::set<T> getDependsOn(T dependency);
+		std::vector<T> getTopoSort();
+		static void test();
+	private:
+		//backing data structures
+		std::map<T, std::map<T,bool>> adjMatrix;
+		std::set<T> verticies;
+};
+
+template <class T>
+Poset<T>::Poset() {
+	//Nothing needed
+}
+
+template <class T>
+Poset<T>::~Poset() {
+	//Ditto
+}
+
+
+template <class T>
+void Poset<T>::addRelationship(T first, T second) {
+	verticies.insert(first);
+	verticies.insert(second);
+	adjMatrix[first][second] = true;
+}
+
+template <class T>
+bool Poset<T>::zeroDependencies(T vertex) {
+	auto depMapItr = adjMatrix.find(vertex);
+	if (depMapItr == adjMatrix.end())
+		return true;
+	for (auto i : depMapItr->second)
+		if (i.second == true)
+			return false;
+	return true;
+}
+
+template <class T>
+std::set<T> Poset<T>::getDependsOn(T dependency) {
+	std::set<T> vertsThatDependOn;
+	for (auto i : adjMatrix) {
+		auto depItr = i.second.find(dependency);
+		if (depItr != i.second.end() && depItr->second)
+			vertsThatDependOn.insert(i.first);
+	}
+	return vertsThatDependOn;
+}
+
+template <class T>
+std::vector<T> Poset<T>::getTopoSort() {
+	std::vector<T> sorted;
+	std::queue<T> toDo;
+	for (auto i : verticies)
+		if (zeroDependencies(i))
+			toDo.push(i);
+	while(!toDo.empty()) {
+		T current = toDo.front(); toDo.pop();
+		sorted.push_back(current);
+		for (T depOnCurrent : getDependsOn(current)) {
+			adjMatrix[depOnCurrent][current] = false; //Remove the edge to current, since current's now been taken care of
+			if (zeroDependencies(depOnCurrent))
+				toDo.push(depOnCurrent);
+		}
+	}
+	return sorted;
+}
+
+
+//int specilization just for testing
+template<>
+void Poset<int>::test() {
+	std::string result;
+	{
+		Poset<int> poset;
+		for (int i = 0; i < 20; i++)
+			poset.addRelationship(i,i+1);
+		result = "";
+		for (int i : poset.getTopoSort())
+			result += intToString(i) + " ";
+		//std::cout << result << std::endl;
+		assert(result == "20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ");
+	}
+	{
+		Poset<int> poset;
+		for (int i = 0; i < 20; i+=2)
+			poset.addRelationship(i,i+1);
+		result = "";
+		for (int i : poset.getTopoSort())
+			result += intToString(i) + " ";
+		//std::cout << result << std::endl;
+		assert(result == "1 3 5 7 9 11 13 15 17 19 0 2 4 6 8 10 12 14 16 18 ");
+	}
+
+	std::cout << "Poset tests passed" << std::endl;
+} 
+
+#endif