should be it

external/duckdb/tools/shell/include/shell_renderer.hpp

@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//                         DuckDB
+//
+// shell_renderer.hpp
+//
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include "shell_state.hpp"
+
+namespace duckdb_shell {
+struct ShellState;
+
+class ShellRenderer {
+public:
+	explicit ShellRenderer(ShellState &state);
+	virtual ~ShellRenderer() = default;
+
+	ShellState &state;
+	bool show_header;
+	string col_sep;
+	string row_sep;
+
+public:
+	static bool IsColumnar(RenderMode mode);
+};
+
+struct ColumnarResult {
+	idx_t column_count = 0;
+	vector<string> data;
+	vector<int> types;
+	vector<idx_t> column_width;
+	vector<bool> right_align;
+	vector<const char *> type_names;
+};
+
+struct RowResult {
+	vector<const char *> column_names;
+	vector<const char *> data;
+	vector<int> types;
+	sqlite3_stmt *pStmt = nullptr;
+};
+
+class ColumnRenderer : public ShellRenderer {
+public:
+	explicit ColumnRenderer(ShellState &state);
+
+	virtual void RenderHeader(ColumnarResult &result) = 0;
+	virtual void RenderFooter(ColumnarResult &result);
+
+	virtual const char *GetColumnSeparator() = 0;
+	virtual const char *GetRowSeparator() = 0;
+	virtual const char *GetRowStart() {
+		return nullptr;
+	}
+
+	void RenderAlignedValue(ColumnarResult &result, idx_t i);
+};
+
+class RowRenderer : public ShellRenderer {
+public:
+	explicit RowRenderer(ShellState &state);
+
+	bool first_row = true;
+
+public:
+	virtual void Render(RowResult &result);
+
+	virtual void RenderHeader(RowResult &result);
+	virtual void RenderRow(RowResult &result) = 0;
+	virtual void RenderFooter(RowResult &result);
+};
+
+} // namespace duckdb_shell