Slack上提出了有关如何验证可选键的问题。我本来想指向s/keys的docstring，但发现可能需要一些澄清。问题中的docstring
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clojure.spec.alpha/keys
([& {:keys [req req-un opt opt-un gen]}])
Macro
Creates and returns a map validating spec. :req and :opt are both
vectors of namespaced-qualified keywords. The validator will ensure
the :req keys are present. The :opt keys serve as documentation and
may be used by the generator.
The :req key vector supports 'and' and 'or' for key groups:
(s/keys :req [::x ::y (or ::secret (and ::user ::pwd))] :opt [::z])
There are also -un versions of :req and :opt. These allow
you to connect unqualified keys to specs. In each case, fully
qualfied keywords are passed, which name the specs, but unqualified
keys (with the same name component) are expected and checked at
conform-time, and generated during gen:
(s/keys :req-un [:my.ns/x :my.ns/y])
The above says keys :x and :y are required, and will be validated
and generated by specs (if they exist) named :my.ns/x :my.ns/y
respectively.
In addition, the values of *all* namespace-qualified keys will be validated
(and possibly destructured) by any registered specs. Note: there is
no support for inline value specification, by design.
Optionally takes :gen generator-fn, which must be a fn of no args that
returns a test.check generator.
我原本期待看到一些类似于，如果指定了:opt或:opt-un的键存在，它们将与这些键的规范进行验证的内容。然而，它只提到它们作为文档提供。
这似乎可能需要一些澄清。
