Start of new ANTLR4 based parser.

Very simple tests pass.

pglablib/sqlast/SelectStatement.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "Statement.h"
+#include <memory>
+
+namespace sqlast {
+
+    class SelectList;
+
+    class SelectStatement: public Statement
+    {
+    public:
+        SelectStatement();
+
+        SelectList* GetSelectList();
+        void SetSelectList(std::unique_ptr<SelectList> value);
+
+    private:
+        std::unique_ptr<SelectList> selectList;
+    };
+
+}