👋 Hello friends! I'm getting my feet wet with transducers + core.async, but have hit a snag and can't find any answers via the Googles... how might I (if it's even possible) pass an argument to a transducer - not a reducing function but a parameter arg - within a comp? https://github.com/loganpowell/cljs-guides/blob/master/src/http-requests/core.cljs#L476

I got this to work before I tried to compose the stats-xform into the transducer, but I don't know how to pass in a second arg later, when using it as a channel xform

sequence is not a transducer

^^

Hi @hiredman! I should pull that out... the xf-zip-census is a transducer... sorry...

Here's the last working example: https://github.com/loganpowell/cljs-guides/blob/6fec50ed7c614c22534d644efd04b2f12e2de80c/src/http-requests/core.cljs#L468

from the previous commit

I transducer is, sort of definitionally, a function that takes a reducing function and returns a reducing function

Is there a way I can wrap it to pass a second arg in?

no

you create a function that returns a transducer instead

ah, ok, so anything that the transducer need to run has to be statically defined

ah...

I see, so wrap a transducer in another function

like map isn't a transducer, but (map f) is

ok, let me chew on that a bit... thank you as always!

cat is the only example in core of a function that is a transducer itself (rather than a function that returns one)

I sent out some props to you in there 😉

btw, I'm not sure if I shared this before, but I posted a getting started guide based on your last help: https://github.com/loganpowell/cljs-guides/blob/master/src/guides/core-async-basics.md and on medium: https://medium.com/@loganpowell/cljs-core-async-101-f6522faf536d

Gotcha @alexmiller I'm struggling, but it's very satisfying to see it all come together when it does.

btw, @alexmiller I'm reading your book "Clojure Applied"! ❤️

ok, let me get back to it 🙂

Great! If you like it, leave a review on Amazon :)

You got it

Any idea why the filter step in the composition is getting skipped?

:thinking_face:

that ->map in the name is odd, because the filter ensures that each value coming through is a map, which is different from turning something into a map

Yes, I'm trying to filter out all items that aren't of type PersistentArrayMap

Hi @noisesmith!

All the transducers work in isolation, but it's weird that when I comp them, the two on the outside (not (filter map?)) work

there are things that are not PersistentArrayMap that are accepted by map?, and counting on that specific type is never a good idea

btw, @hiredman your advice helped alot to get me this far

I fixed it by changing the upstream transducer. Sorry for hogging the air!