Just an add, I was thinking if we could have something like a "deref" running during the transducers, in order to enable value unwrapping (that way we could handle channels/values in same fashion). I understand that is complicated maybe because overhead, and also more tricky into JS world were you can't deref a channel into a sync fashion.
But the point remains, there is way to seamlessly handle async and sync operations using the same transducers? Or something like it. Best regards. --- Wilker Lúcio http://about.me/wilkerlucio/bio Woboinc Consultant +55 81 82556600 On Sun, Sep 21, 2014 at 7:01 PM, Wilker <wilkerlu...@gmail.com> wrote: > Hi guys, > > I'm playing with transducers here, and trying out stuff just for fun, > there is something that I'm kind stuck on how to approach. I understand the > great abstraction that transducers provide over don't carrying about the > input source type, but I'm struggling to deal with async operations into my > pipeline. > > For example, I'm working with Node.JS async API's for file system > operations, I want to stick with the async versions since I don't wanna > block the event loop of Node. > > So, let's say I have a source with ["dir", "other"] and I wanna create an > operation that will simple filter which paths exists, are directories, and > then list the `ls` of each remaining entry. > > So, I first created "channel returning" functions for the Node operations, > I'll not put the code here because I don't think it's really relevant here, > just consider that I have them. > > So, my pipeline would start looking something like this: > > (comp (filter exists?) > (filter is-dir?) > (mapcat readdir)) > > Of course, this doesn't works... Because `exists?`, `is-dir?` and > `readdir`, all of them return channels, so the filter would always pass > since a channel is always a valid value... The same applies to mapcat, it > would try to concat into a channel... > > This is making me notice some barrier to be able to compose async > operations with regular operations. > > Maybe would be possible to "sign" somehow operations to make then run > async? > > The only viable option that I've found is with pipeline-async, which > accepts an async function, but that doesn't composes with the other > operations (map, filter, drop-while...) > > Is there already a solution to that? Or maybe I'm just doing it wrong and > there is a better way to handle those cases? > > I would love to know how you guys are handling those kind of situations. > > Thanks. > > --- > Wilker Lúcio > http://about.me/wilkerlucio/bio > Woboinc Consultant > +55 81 82556600 > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
