经典的Lisp倾向于用列表表示所有的东西，然后用car，cdr，cadr等手动浏览它们。这种风格有几个问题，特别是难以阅读，易出错，并且妨碍生成合适的类型错误报告。
Guix code should define appropriate data types (for instance, using
define-record-type*) rather than abuse lists. In addition, it should
use pattern matching, via Guile’s (ice-9 match) module, especially
when matching lists (see Pattern Matching in GNU Guile Reference
Manual); pattern matching for records is better done using
match-record from (guix records), which, unlike match,
verifies field names at macro-expansion time.