Ali,
I don't have any colour on the underlying cause of the problem, but I'd be
interested to know whether you see it with 'case' as well as 'cond', as I
vaguely remember running into something like this (in cljs, only).
Take care,
Moe
On Tue, Mar 20, 2018 at 7:33 AM, <outrov...@gmail.com> wrote:
> Hello,
>
> I'm running into a very strange issue which, having searched the web, no
> one seems to have reported.
>
> In short, I have a go block similar to the following (simplified for
> posting purposes, however I can post the full code if required):
>
> (go
> (while true
> (let [[cmd event-args] (<! mouse-chan)]]
> ...
> (cond
> (= cmd :down)
> (let [ ... ] ...)
>
> (= cmd :in)
> (let [ ... ] ...)
>
> (= cmd :hover)
> (let [ ... ] ...)
>
> (= cmd :handle-down)
> (let [ ... ] ...)
>
>
> )
> ))
>
>
> Essentially I have a number of mouse handlers (mousedown, mouseup,
> mouseover, mouseout, ...) which put! a [cmd event-args] vector onto
> mouse-chan, which is subsequently taken in the above block.
>
> Generally speaking, the block compiles successfully, however under certain
> conditions it just "breaks", specifically by producing a:
>
> java.lang.StackOverflowError
>
> during compilation.
>
> At present I have 4 branches within the cond block. Within one of those
> branches I have a loop/recur which takes (via <!) from the same channel as
> in the outermost block. This works absolutely fine until I try one of the
> following, which results in the above compilation error:
>
> * adding a fifth branch
>
> * with just the 4 branches in place, if I add even something as simple as
> the following expression:
>
> (when major-in
> (major-in event-args))
>
> where major-in is either a function or nil
>
> * and the strangest thing of all, if I simply use *map deconstruction* at
> one point in one of the cond branches, I also get the same compilation
> error:
>
> (let [{:keys [x y w h]} (rect-ent-layout ghost-rect)
> ;; Even this doesn't work if I uncomment it and comment out the
> previous
> ;; {} ()
>
> ] ...)
>
> but doing the following, which doesn't involve deconstruction, is fine:
>
> (let [stuff (rect-ent-layout ghost-rect)
> x (:x stuff)
> y (:y stuff)
> w (:w stuff)
> h (:h stuff)] ...)
>
> In terms of limitations on core.async go blocks, I am only aware of the
> functional boundary limitation, namely that you cannot create anonymous
> functions within a go block which perform any puts/takes, asynchronous or
> otherwise. Beyond that I can't find anything in the documentation which
> would indicate that there are any other limitations.
>
> I am also aware that some macros do create functions, e.g. for, but I am
> not using anything like that.
>
> I'm running a CLJS project with the following dependencies:
>
> [org.clojure/clojure "1.9.0-beta4"]
> [org.clojure/clojurescript "1.9.946"]
> [org.clojure/core.async "0.3.443"]
>
> I'm also using Reagent and developing using Figwheel. The Compilation
> Error in fact is show in a Figwheel overlay.
>
> I have tried to isolate the issue but I can't seem to pinpoint what
> exactly is causing it.
>
> Has anyone every come across something like this before when working with
> core.async, specifically the java.lang.StackOverflowError compilation
> error? If not, without posting the full code, can anyone see anything
> with the above code which might cause such an issue?
>
> Thank you,
>
> Ali
>
> --
> Note that posts from new members are moderated - please be patient with
> your first post.
> ---
> You received this message because you are subscribed to the Google Groups
> "ClojureScript" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to clojurescript+unsubscr...@googlegroups.com.
> To post to this group, send email to clojurescript@googlegroups.com.
> Visit this group at https://groups.google.com/group/clojurescript.
>
--
Note that posts from new members are moderated - please be patient with your
first post.
---
You received this message because you are subscribed to the Google Groups
"ClojureScript" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojurescript+unsubscr...@googlegroups.com.
To post to this group, send email to clojurescript@googlegroups.com.
Visit this group at https://groups.google.com/group/clojurescript.
