usql update

usql/lexer.h

@@ -25,6 +25,12 @@ namespace usql {
 	keyword_drop,
 	keyword_table,
 	keyword_where,
+	keyword_order,
+	keyword_by,
+	keyword_offset,
+	keyword_limit,
+	keyword_asc,
+	keyword_desc,
 	keyword_delete,
 	keyword_update,
 	keyword_load,
@@ -41,6 +47,10 @@ namespace usql {
 	keyword_integer,
 	keyword_float,
 	keyword_varchar,
+	keyword_date,
+	keyword_bool,
+	keyword_distinct,
+	keyword_show,
 	int_number,
 	double_number,
 	string_literal,
@@ -85,8 +95,6 @@ namespace usql {
 
 	TokenType nextTokenType();
 
-	TokenType prevTokenType();
-
 	static bool isRelationalOperator(TokenType token_type);
 
 	static bool isLogicalOperator(TokenType token_type);
@@ -96,7 +104,7 @@ namespace usql {
     private:
 	TokenType type(const std::string &token);
 
-	std::string stringLiteral(std::string token);
+	static std::string stringLiteral(std::string token);
 
 	static std::string typeToString(TokenType token_type);