cljc-flow

cljc-flow is a port of clojure.core.async.flow to squint. This README calls clojure.core.async.flow "upstream". cljc-flow ports the code of core.async 1.10.874-alpha3. A .cljc file that uses flow runs on the JVM with upstream and in JavaScript with cljc-flow.

Motivation

I wanted to write flow code that runs on the JVM and in JavaScript. Upstream runs only on the JVM, because each process runs on a thread. Because squint compiles an ^:async fn to a JavaScript async function, cljc-flow uses promises where upstream uses threads, and a go macro is not necessary.

If upstream makes flow cross-platform, this project is no longer necessary.

Install

npm install cljc-flow

(ns my.app
  (:require #?(:clj  [clojure.core.async :as a]
               :cljs ["cljc-flow/core" :as a])
            #?(:clj  [clojure.core.async.flow :as flow]
               :cljs ["cljc-flow/flow" :as flow])))

Use

Use the upstream documentation: the flow guide and the API docs. Where cljc-flow is different from upstream, the docstring has a note that starts with cljc-flow:.

The tests show how to write one source for the two platforms. A parity suite in test/cljc_flow/ runs against core.async on the JVM and against cljc-flow on squint. harness.cljc has the code that is different on each platform. On squint, ::flow/stop is not upstream's keyword. upstream_flow_test.cljc shows an :as-alias require that gives the correct keywords.

Tests

bb test           the parity suites on the JVM and on squint,
                  then the squint-only suite
bb test:browser   the channel suites in headless Chromium

Before the first bb test:browser, install a browser: npx playwright install chromium.

License

cljc-flow is a derivative work of clojure.core.async, under the same license.