Extract preprocessing from tokenizer

include/preprocessor/preprocessor.hpp

@@ -0,0 +1,21 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Preprocessor
+{
+private:
+	std::vector<std::string> substitutionIdentifiers;
+	std::vector<std::string> substitutionValues;
+
+	void extractComment(std::string & line,
+		std::size_t const lineNumber,
+		std::size_t const lineColumn);
+
+	void processLine(std::string & line, std::size_t const lineNumber);
+
+public:
+	void process(std::vector<std::string> & lines);
+
+	void printSubstitutions() const;
+};