> I'm writing some Java at the moment for an Android app, and it's just killing me after doing Scheme and Python

Android isn't Java though. It's some frankenstein contraption made from a mutated version of Java from a decade ago.

> I were starting my own business now, I'd use Clojure or Scala.

I personally wouldn't ever choose Scala for anything. It's tooling is horrible (Sbt is a special hell, and scalac is as slow as a C++ compiler).

I'm currently in a code base like you describe, scala core with a switch to Java. It's not fun. Were stuck with these legacy library and framework choices that don't fit into the Java ecosystem and it slows down development considerably.

> ... and scalac is as slow as a C++ compiler

Scalac is as fast as Javac if you don't overuse Scala-specific features which are known to compile slowly - implicits and macros. But it is unfair to use these features and than complain on compile speed or compare it to a language that doesn't offer similar feature set.

Also, in our Java/Scala project it turned out that Scala+Bloop was way faster (10x-100x) at incremental compilation than Java+Gradle. Bloop is based on SBT libraries so there are some things that SBT does right.

Thanks for the compliment. But, as the author of Bloop, I must say that Bloop is definitely not based on sbt and it departs a lot from the design decisions sbt made.

Android is the worst implementation of Java projects - horrible architecture or lack thereof and really bad api design. If anyone wants to learn Java, focus on modern Java language and micro services based frameworks and you can get best of all.

Interesting, I've only read Scala. Personally I like Clojure but thought I should mention it as I see businesses mixing Scala with Java successfully in my work.

You can, but interoperability is not that great. It can work, but often it takes a lot of massaging/converting even basic data types.

Kotlin has wayyy better interoperability with Java

totally agree about sbt being gratuitously complex.

i wonder if Java is judiciously choosing the non crazily digressive parts of Scala, as they both evolve.

That is what Goetz said is the plan for Java. Move slow, let other languages experiment with language features, and then take the best features and implement them better.

Well, so far the “better” still remains to be seen... waiting for type-classes to represent monoids, functors, applicatives, monads and foldable.

So far I’ve just seen a complex and wild stream API that mimics it in practice, without all the mental model behind it.

Oh, and what’s this nonsense with Java Option?! Really?

We're yet to see if monoids, functors, and monads are worth it :)

For better I'd say you should look at things like virtual threads vs async/await or kotlins when vs switch expressions.

If you program modern Java or Kotlin map and flatMap are everywhere. I'd say the debate whether functors and monads are useful is over.

Java or Kotlin support functors or monads as design patterns, i.e. this is how a map/flatMap works with an Optional or a Stream.

The question is: if this support is enough or should the type system be enhanced so you can abstract over/compose a functor and/or a monad ?

The answer to this question is IMO still open.

No they are. Seriously, the mental effort I had to endure to hold all these wild APIs in my head! In hindsight it’s infuriating; the gatekeeping, the patronizing condescendence when I was struggling with what are mathematical trivialities.

Screw that... I should have been told sooner

Nice : as an ex Scala person for a few years, seems smart.

Sbt optional right? Can use maven or whatever else of you want.

Androidifed Java is the worst thing you can deal to be honest.

Can you just use Kotlin to avoid Android's Java, or are there instances where you need to dip into Java get stuff done?

Kotlin is like a tape on the ugly Android architecture, little helpful but still a monstrosity compared to iOS.

ok that makes me feel better. God it's awful.

Please use Kotlin on Android. Java on Android is a de-fanged and lame tiger with half the modern standard library and language features missing. Blame both Oracle and Google for this.

Having finished my first little app for Android in Java, I will certainly be switching. :-)

Why would you make technical decisions based on what hyponthenictal new owners would prefer in a hyponthenictal acquisition in 5 years?

Because that's how founders make money. The vast majority of exits now are purchases by private equity firms, and they will do a thorough technical due diligence and look at those decisions and what it will take to run the company the way they want to. (I do those diligences for a living) If you're doing a tiny lifestyle company with no exit plan, you wouldn't. Which ironically, is exactly what I'm doing on my own time, so I use Scheme for that. :-)

Most exits are purchases by private equity? I had no idea - are there any references for that available?

Here's one report I used for a presentation. The quote of interest:

"Over the last 12 months, 75 per cent of the most active “buyers” of $100m+ technology companies have been PE firms. This is despite the fact that the combined cash balances of the “Big Five” tech companies is an eye-watering $330 billion. Today’s most active tech buyers are private equity firms like Silver Lake, Francisco Partners, and Vista Equity. Not Google, Facebook or Amazon."

https://ftalphaville.ft.com/2019/01/07/1546862666000/Guest-p...

One of the things that is not obvious to people coming from the VC world is that once the company has gone from VC to PE, it's likely going to get flipped several more times from PE to PE. At a guess, I'd say 3/4 of what I look at are one PE to another. Depending on the firm, they will sell every 3 to 7 years or so.

iain

What's "hyponthenictal"?

You used it twice, but it's not on Google...

It's a misspelling of "hypothetical"

> I'm writing some Java at the moment for an Android app, and it's just killing me after doing Scheme and Python, but I have to admit, if that start-up had used Java or C#, they might have been better off in the long run.

that’s a logical fallacy. chances are that if they used Java or C# they might be dead by now (ie it sucks but usually it’s a good problem to have)

I know what you're getting at, and I agree with the sentiment very often, most of the time even. But in this particular case, I don't think so, and believe me, I spent a lot a of time thinking about that....

So what are your thoughts?

Uh hard. First, maybe don't buy companies with bad technical debt, just start from scratch? And always prefer two experts to 10 juniors in the beginning even if you move more slowly at first. I don't know what would have worked well in that particular situation, but if I were to do it again and could influence the original team, I'd use Clojure. I believe the immutability and control of side effects would have been more of a benefit than types. That was where the real problems came from, dynamic ability to create out-of-sight side effects and alter data in unexpected ways all over the damn place. Clojure's immutability plus spec would have been way better.