another bit of refactoring

usql.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "parser.h"
+#include "table.h"
+
+#include <string>
+
+namespace usql {
+
+    class uSQL {
+
+    public:
+	std::unique_ptr<Table> execute(const std::string &command);
+
+    private:
+	std::unique_ptr<Table> execute(Node &node);
+
+	std::unique_ptr<Table> execute_create_table(CreateTableNode &node);
+	std::unique_ptr<Table> execute_insert_into_table(InsertIntoTableNode &node);
+	std::unique_ptr<Table> execute_select(SelectFromTableNode &node);
+	std::unique_ptr<Table> execute_delete(DeleteFromTableNode &node);
+	std::unique_ptr<Table> execute_update(UpdateTableNode &node);
+	std::unique_ptr<Table> execute_load(LoadIntoTableNode &node);
+
+	Table *find_table(const std::string name);
+	std::unique_ptr<Table> create_stmt_result_table(int code, std::string text);
+
+
+    private:
+	bool evalWhere(Node *where, Table *table,
+		       std::vector<Row, std::allocator<Row>>::iterator &row) const;
+
+	std::unique_ptr<ValueNode> evalNode(Table *table, std::vector<Row, std::allocator<Row>>::iterator &row,
+					    Node *node) const;
+
+	bool evalRelationalOperator(const RelationalOperatorNode &filter, Table *table,
+				    std::vector<Row, std::allocator<Row>>::iterator &row) const;
+
+	bool evalLogicalOperator(LogicalOperatorNode &node, Table *pTable,
+				 std::vector<Row, std::allocator<Row>>::iterator &iter) const;
+
+	std::unique_ptr<ValueNode> evalArithmetic(ColumnType outType, ArithmeticalOperatorNode &node, Table *table,
+						  std::vector<Row, std::allocator<Row>>::iterator &row) const;
+
+    private:
+        Parser m_parser;
+	std::vector<Table> m_tables;
+    };
+
+}