Checked behavior in 1.13 destructuring outside of `:keys!` like directives

Mon, 12 Oct 2026 14:12:23 +0000

With 1.13 Clojure introduces new directives to associative destructuring. Is there a way to get the checked behavior (throw when the key isn't present) on keys destructured without using :keys! like directives ?

I like being able to have vars holding keywords. It allows me to document them and it's also convenient in the case of typos since I tend to catch them sooner in var names rather than in keywords.

For instance consider the follow example :

(def foo
   "My nice doc for foo."
   ::foo)

(def bar
  "My nice doc for bar."
  ::foo)

(def example-map {foo :value})

;; How do I say here that I want foo and bar to be present without a `:keys!` directive ?
(let [{foo-binding foo
            bar-binding bar} example-map]
  [foo-binding bar-binding])

If there isn't a way, would a :checked directive be a good idea :

;; This would throw, `bar` is absent from `example map`
(let [{:checked {foo-binding foo
                   bar-binding bar}} example-map]
  [foo-binding bar-binding])

A :& directive meaning checked and unbound could also be possible:

;; This would throw, `bar` is absent from `example map` but it wouldn't be bound
(let [{:checked {foo-binding foo}
       :& {bar-binding bar}} example-map]
   [foo-binding])

Did I miss that feature somehow? If not what do you think about :checked and
:& directives ?

Cheers,

Edit:

I just thought of another use case for a :checked like directive. Directive-less destructuring allows for binding names different from keyword names. We can do :

(let [{id1 :a/id
       id2 :b/id} some-map]
  ...)

Whereas:

(let [{:keys! [:a/id :b/id]} some-map]
   ...)

does not let you have different bindings for keyword sharing the same name.

Leaving aside the var holding keywords pattern that may be a bad idea. Would the binding of namespace qualified keywords sharing the same name be a valid argument to consider a :checked like directive?

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Checked behavior in 1.13 destructuring outside of `:keys!` like directives