interpreter_tree first iteration

include/node.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <cstddef>
+
+// for clangd
+#include "parse_tree.hpp"
+
+namespace info {
+  class GlobalInfo;
+  class Context;
+} // namespace info
+
+namespace interpreter {
+class Visitor;
+
+struct Node {
+//public:
+  Node(info::GlobalInfo& global_info) : global_info_(global_info) {}
+
+  virtual void Accept(Visitor* visitor);
+
+  /* ------------ use visitor instead ------------
+  virtual void build(parser::ParseTree::Cursor& cursor) = 0; // build tree from parse tree
+
+  virtual void find_symbols() = 0; // find types, typeclasses, namespaces, ..
+  virtual void assign_types() = 0; // typecheck
+  virtual void execute(info::Context& context) = 0; // execute part of tree
+  */
+/*private:
+  size_t start_position_; // ??
+  size_t end_position_; // ??
+  Node* parent_; // ??
+  info::GlobalInfo& global_info_;*/
+};
+
+} // namespace interpreter