I'm exploring the capabilities of a standalone cljs compiler through cljs.main. I wrote a simple script like this:

bash
clj --main cljs.main --compile demo.core --repl --repl-opts repl.edn

clojure
{:watch "src"
 :watch-fn (fn [] (.alert js/window 1))}

@achikin no. I'm pretty sure you can't specify :watch-fn via deps.edn at all since its not evaluated

it is also run on the Clojure side to call a Clojure function when the build completes

I'm seeing an analysis issue in cljdoc that only occurs with ClojureScript:

Unable to resolve var: *runtime-asserts* in this context

Are any work arounds to having a promise in cljs? (the Clojure definition of a promise, not the es6 one)

Google only yields ways of dealing with javascript promises

unless you are using graalvm you only get js promises

(you can't block in JS so a blocking deref is not possible no matter which way you try)

:C

@pablore https://github.com/funcool/promesa has async/await macros that give you the equivalent of the JS async/await, which will let you unwrap promises from within an async function - it uses state machine code along similar lines to what go blocks do in core.async (or similar to how async/await works in JS, incidentally). Essentially pausing the async function until the promise is resolved

@jesse.wertheim that library look very cool, but it doesn’t has the same api as Clojure’s promises. I can’t deliver values to them which is what I want

yeah, all you can do in cljs is fake it within the context of a state machine, since JS uses a single-threaded event loop and can't block

I've been getting some warnings when I build my project. This happens when making an uberjar with advanced compilation and when using lein figwheel: Everything appears to work fine, though. Are these warnings noteworthy in any way? I'm using Clojure 10.10.0-beta5 and Clojurescript 1.10.439

WARNING: cljs.core/bit-or, all arguments must be numbers, got [string number] instead at line 117 target/cljsbuild/public/js/cljs/tools/reader/edn.cljs
WARNING: cljs.core/bit-or, all arguments must be numbers, got [string number] instead at line 117 target/cljsbuild/public/js/cljs/tools/reader/edn.cljs
WARNING: cljs.core/bit-or, all arguments must be numbers, got [string number] instead at line 118 target/cljsbuild/public/js/cljs/tools/reader/edn.cljs
WARNING: cljs.core/bit-or, all arguments must be numbers, got [string number] instead at line 118 target/cljsbuild/public/js/cljs/tools/reader/edn.cljs

@pablore oh wait, do you mean the semantics of (def foo (promise)) and (deliver foo some-value)? because this you can do with a little interop wrapping

yes!

ahh ok, in that case one sec...

@vheuken You probably want the version of tools.reader with https://github.com/clojure/tools.reader/commit/c5421fd8809784ef893e2afaf0d8996229864908

Upgrading tools.reader to 1.3.2 (latest version at the time) got rid of the warnings. Thanks!