-struct expression *expr_parse (struct dataset *, enum expr_type);
-struct expression *expr_parse_pool (struct pool *,
- struct dataset *,
- enum expr_type);
+struct expression *expr_parse (struct lexer *, struct dataset *, enum val_type);
+struct expression *expr_parse_bool (struct lexer *, struct dataset *);
+struct expression *expr_parse_new_variable (
+ struct lexer *, struct dataset *,
+ const char *new_var_name, const struct msg_location *new_var_location);