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clojure 2026-05-25
weavejester 2026-05-25T13:28:34.290119Z
Quick question around primitive mutables in deftype:
(defprotocol P (set-b! [_ b]))
(deftype T [^:volatile-mutable ^boolean b]
P (set-b! [_ b'] (set! b ^boolean b')))Must assign primitive to primitive mutable: b
p-himik 2026-05-25T13:40:00.114289Z
(deftype T [^:volatile-mutable ^boolean b]
P (set-b! [_ b'] (set! b (boolean b'))))weavejester 2026-05-25T13:41:43.481419Z
Ah, thanks!
p-himik 2026-05-25T13:42:08.128319Z
AFAICT, set-b! being a protocol function prevents the b argument from being a primitive.
So the ^boolean b' hint makes no sense - b' is never a primitive there. So you gotta coerce it.
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weavejester 2026-05-25T13:43:21.525309Z
Right, I see. I guess I could always use definterface, but probably not worth the few nanoseconds I'd get from avoiding the coercion.
oyakushev 2026-05-26T09:38:13.814309Z
This is not much about protocols, no Clojure functions support primitive arguments beyond longs and doubles.set-b!being a protocol function prevents thebargument from being a primitive.
p-himik 2026-05-26T10:16:11.069079Z
Ah, of course.
But it works in the exact same way with long anyway. :)
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