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itaied 2025-08-13T08:57:24.274779Z
FIRST stops navigation if the collection is empty.
i want to use the nil->val at the end [:coll FIRST :x :y :z (nil->val 42)]
is there a nav that doesn't stop navigation equivalent for FIRST?
itaied 2025-08-13T09:10:27.821059Z
in the meantime i have created my own nav
(sp/defnav FIRST []
(select* [this structure next-fn] (next-fn (first structure)))
(transform* [this structure next-fn]
(let [structurev (vec structure)
ret (next-fn (first structure))]
(if (vector? structure)
(assoc structurev 0 ret)
(cons ret (rest structure))))))
Samuel Ludwig 2025-08-13T14:24:10.045999Z
not exactly what you're looking for but this, i think, would also give you an equivalent outcome, at the cost of some slight verbosity/repetition
`(select-one [:coll (s/nil->val [42]) FIRST :x :y :z (s/nil->val 42)] []) ;=> 42`
(edit: might be incorrect for how your data is actually structured)
nathanmarz 2025-08-13T15:30:31.854709Z
in a select you can just do (view first)
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