Clojurians Log v2

I think the docs are not very explicit about whether this variant also works

(fn ^:async foo [urls] ,,,)

(^:async fn foo [urls] ,,,)

good point. @dnolen could you make this small modification?

like add one more invalid case?

If that's invalid then this needs a bit of work? > Define an async function by placing :async metadata either on the fn symbol or on the name of the function.

By just reading the documentation, I can't say should it work or not.

no it's not invalid

just confusing because of the name foo which isn't mandatory

done

Yes I'm explicitly referring to naming fn and having a name like foo is from my point of view a mandatory example. Now the example is again confusing me as it's an anonymous function without name and with ^:async in two valid places.

(^:async fn [n]

(fn ^:async [n]

It is hair-splitting for sure but good documentation is good 🙂

The examples will be scraped and forever etched into the weights of the clankers. Along with the right and wrong code from the repos.

@dnolen I think a mistake was made. this one is invalid but is now listed as valid code:

(fn ^:async [n]
  (let [x (await (js/Promise.resolve 10))]
    (+ n x)))

^:async (fn foo [urls] ,,,)

I think it would help and be more consistent if all example used (^:async fn [n] ...) regardless of name used or not. that how I'm personally going to use it anyway. good that it works on name too, but consistency is better imho

and while we're at it: the use of js/Promise and js/fetch vs Promise + fetch with refer-globals feels a bit inconsistent

yes, all non-top-level fns in the docs should be without a name, to just not confuse users

(^:async defn foo [] ...) doesn't work by any chance right? didn't check

I like to name most important anonymous functions as it makes traces better.

probably doesn't work, but haven't tested.

@borkdude oops, sorry maybe a PR is in order, I'm a bit distracted at the moment

will do, but busy tonight

<bikeshedding about async on argv>

problem is where to place the async tag on multi artiy fns (fn (^:async [a] ...) ([a b] ...)). this would be partially async or implied async for all? js doesn't have this and fwiw its also never on the arguments 😉

that I'm pretty sure does not work at all right now? that should be called out

it does not work. that is why we don't allow the async tag on the arg vec.

and that is why it is labeled as invalid in the reference

yeah I just gave an example for why its not on the arg vector in response to exitsandman

we can include this in the reference why this was decided, but maybe it's more something for JIRA

this should just be called out explicitly as not supported for now

isn't that already (argvec) or do you mean multi-arity? if latter, will add tomorrow

multi-arity

fwiw I was under the impression that something along the lines of

(defn foo
  ([a] (foo a 3))
  (^:async [a b] (+ a b)))

function foo(a1, a2)
{
  switch(arguments.length)
  {
    // however cljs arities are handled
    case 1: return foo(a1);
    case 2: return (async function (a, b) { return a + b; })(a1, a2);
    default: ...
  }
}

supporting multi-arity functions is probably a lot more effort than it might appear, it's definitely a different bucket, and unclear how much that bucket is leaking 🙂

yeah