[_bsless]

That's a fair criticism, but indulge this hypothetical, if you will:

- assume the sliding window transducer existed in the standard library (there's an open jira for it)

- assume the programmer is not an expert, but is familiar with stuff like boxed maths in Clojure, which isn't hard to work around, well documented [1], and has a known performance impact

- assume the programmer will avoid using `last`

- assume the programmer is comfortable using transducers

In short, that the transducer exists and the programmer has at least 6 months of experience programming in Clojure full time.

Will you consider the resulting implementation complicated, in depth or non idiomatic? There's always the possibility I'm just used to it so it comes naturally to me, but as the title suggests, I consider the result, before dropping down to arrays, way more idiomatic than the initial implementation.

I don't begrudge CL's speed and implementation, it's the readiness with which Clojure is dismissed as being slow with only surface familiarity with it.

[1] - https://insideclojure.org/2014/12/15/warn-on-boxed/