Clojurians Log v2

What should a hypothetical 0-arity distinct? return?

> arguments are not distinct if there is a repetition. there is no duplicate in an empty list So true I assume.

Yeah, plenty of such cases. But it makes sense, there's no identity element for distinct?. (+) returns 0 because it's its identity element, same for (*) and 1. Or (and) and true, or (or) and nil.

hmmm. not sure it makes sense. arguments are not distinct if there is a repetition. there is no duplicate in an empty list.

functions like every behave correctly on an empty sequence

i’m only using this for debugging so no great harm done.

on the other hand = cannot be called with 0 arguments

at least according to the documentation

I guess it could be argued any way. Maybe I'm wrong and identity values are completely irrelevant since distinct? is not an algebraic operation but a relational predicate, similar to =. In any case, if you'd like to see (distinct?) working, the best thing to do would be to create a post at https://ask.clojure.org. > functions like every behave correctly on an empty sequence every? is a sequence-function, not an item-based function, it doesn't require apply. And it's almost the same as (apply and (map pred coll)), and and has an identity value which is also true. Same with some - it works with empty colls and returns nil.

you probably have an alternative, but just in case, (if-let [l (seq some-list)] (apply distinct? l) true)

why request a core feature instead of just writing a helper fn

• If it makes sense from the language design perspective, the language will become better • If others need it, nobody will have to write the helper function anymore

Or (apply distinct? (or (seq some-list) [1]))

I'd go with

((some-fn empty? (partial apply distinct?)) [])
true