lang: ast: implement for-loop parsing

lang/ast/expr/expr.c

@@ -40,15 +40,16 @@ struct ast_node_type expr_node_ops = {
 	},
 	.n_keyword_parsers = {
 		/* statement keywords */
+		KW_PARSER(FOR, stmt_parse_for),
 		KW_PARSER(WHILE, stmt_parse_while),
 		KW_PARSER(MATCH, stmt_parse_match),
 		KW_PARSER(IF, stmt_parse_if),
 		KW_PARSER(THEN, stmt_parse_end),
 		KW_PARSER(ELSE, stmt_parse_end),
-		KW_PARSER(DO, stmt_parse_end),
 		KW_PARSER(END, stmt_parse_end),
 
-		/* operator keywords */
+		/* operator/block keywords */
 		KW_PARSER(IN, arith_parse_in),
+		KW_PARSER(DO, arith_parse_do),
 	}
 };