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Comment by kbd | Hacker News Reader

The biggest thing keeping me from ever seriously learning Clojure is the JVM. Slow startup time means I'd never use Clojure for "scripts", and I certainly don't want to have to manage the JVM in production scenarios, so when would I use Clojure? If there was a native version that could produce static binaries like Go/Nim/Rust I'd be much more interested to learn it.

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I found managing production JVM is amazing. In fact, little other runtimes come close in my opinion. What don't you like about it?

For scripting, there's a lot of ways to script efficiently with Clojure, it's actually great for it as well. So, for most my scripts, I don't really mind waiting 1 second for them to start. That said, if you wanted them to start faster, using ClojureScript takes you under 100ms. And using Joker (https://github.com/candid82/joker) takes you under 50ms.

When I need even faster startup for scripts and also need performant runtime, I've been using GraalVM to compile to native binaries, those start in under 10ms, and execute much faster than ClojureScript and Joker. That's a good strategy if you want to write things like a grep tool, or ls, or a linter, code formater, etc.

By contrast, one principal reason I started learning Clojure was ClojureScript. Making stuff that can run in the browser or as a browser extension is awesome for cross-platform compatibility.

If you like "functional and runs on the JVM" you might like ScalaJS too. It's a mature transpiler, and the community has rallied to ensure that all the important libraries compile both to the JVM and to JS.

Lately GraalVM can be used to compile a native binary, since Clojure compiles down to Java bytecode.

https://www.innoq.com/en/blog/native-clojure-and-graalvm/

Sometimes the trade-off of slow startup vs. having a JIT'ed VM is better, since you get a lot more performance, if you're working w/ long-lived processes.

> I certainly don't want to have to manage the JVM

Of all the things I’m unfortunate enough to have to manage in production, the JVM has never caused me any problems.

I mean, yeah, I’d like static binaries too (graal is promising but not quite there yet), but managing the JVM has nothing to do with it (footprint and startup time are my primary reasons)

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