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From First Principles: Why Scala?

lihaoyi.com

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Re: From First Principles: Why Scala?

#31

Post by strulovich »

mwcampbell wrote: post #20

I dabbled with Scala several years ago, but I've been using Kotlin for a JVM-based project and am happy with it. My main reason for choosing Kotlin is smoother interop with the JVM world. For example: - Scala adds an Option type, whereas Kotlin adds nullability checking for existing object types. - Scala has its own convention for getters and setters, whereas Kotlin automatically turns JVM getters and setters into pr…

This is a good list, and this is why Scala for Android was a no starter. The huge standard library and awkward conversions with Java made it an expensive cost on early phones (and probably still today).

Kotlin also side steps the big standard library by using inline functions a lot (in addition to the mentioned advantage if extending existing Java classes).

To really appreciate Kotlin’s design, one should know some Scala.

Re: From First Principles: Why Scala?

#32

Post by bjarneh »

lihaoyi wrote: post #24
bjarneh wrote: post #17

Scala is one of those great languages with that one Achilles heel. The speed of that compiler: $ time scalac Hello.scala real 0m2,907s user 0m7,901s sys 0m0,308s $ cat Hello.scala object Hello{ def main(args: Array[String]){ println("hello world") } } Implicit type conversion can be debated I guess, but otherwise a very beautiful language.

Yeah cold compiles are slow, but most modern tools keep a hot compiler to re-use and once warm a hot compile of hello world is more like ~200ms. There's a bit of complexity managing these daemons, but that's something that the build tool normaly handles for you transparently

Yes it gets better, and the 'fsc' (Fast Scala Compiler) does improve on the situation somewhat; but I've always found it annoyingly slow. It should be mentioned that I haven't looked very hard at that language in many years for that very reason; so things could have improved somewhat. And from what I understand, the next version of Scala (Dotty) is going address this issue (build speed).

Re: From First Principles: Why Scala?

#33

Post by jolux »

playing_colours wrote: post #22
occupy_paul_st wrote: post #11

I definitely agree that many newer languages are strongly inspired by Scala, but I don't see a strong argument for why to choose Scala over one of a newer hybrid language. My own intuition is that these newer languages have had the benefit of being able to learn from Scala's mistakes. A lot of them have intentionally sacrificed some of the Scala's flexibility to be easier to learn and use. I found Scala to be an extr…

What newer hybrid languages besides Kotlin can cover the benefits you can get with Scala: a solid ecosystem (both for Scala and Java) for developing web applications, microservices, data processing, and good performance. Julia, Rust, and Elixir are all great, but popularity, ecosystem are not there yet.

F#

Re: From First Principles: Why Scala?

#34

Post by lmm »

occupy_paul_st wrote: post #11

I definitely agree that many newer languages are strongly inspired by Scala, but I don't see a strong argument for why to choose Scala over one of a newer hybrid language. My own intuition is that these newer languages have had the benefit of being able to learn from Scala's mistakes. A lot of them have intentionally sacrificed some of the Scala's flexibility to be easier to learn and use. I found Scala to be an extr…

> I definitely agree that many newer languages are strongly inspired by Scala, but I don't see a strong argument for why to choose Scala over one of a newer hybrid language. My own intuition is that these newer languages have had the benefit of being able to learn from Scala's mistakes. A lot of them have intentionally sacrificed some of the Scala's flexibility to be easier to learn and use.

I don't believe any of those new alternatives has made better choices; some of them haven't had time to accumulate as many warts as Scala yet, but all of the ones I've seen have design decisions that make them inevitable. Higher-kinded types still work much better than every other way of achieving the same things that's been found - and if you want both higher-kinded types and decent tooling/library support, Scala is still pretty much the only option. (Haskell exists, but even if you consider its tooling good enough, implicit pervasive laziness has huge costs).

Re: From First Principles: Why Scala?

#35

Post by lihaoyi »

bjarneh wrote: post #32
lihaoyi wrote: post #24

Earlier quoted context omitted.

Yeah cold compiles are slow, but most modern tools keep a hot compiler to re-use and once warm a hot compile of hello world is more like ~200ms. There's a bit of complexity managing these daemons, but that's something that the build tool normaly handles for you transparently

Yes it gets better, and the 'fsc' (Fast Scala Compiler) does improve on the situation somewhat; but I've always found it annoyingly slow. It should be mentioned that I haven't looked very hard at that language in many years for that very reason; so things could have improved somewhat. And from what I understand, the next version of Scala (Dotty) is going address this issue (build speed).

The compiler has sped up 3x in the past few years. That's a very big speedup, and the current experience is likely nothing like what you remember

Re: From First Principles: Why Scala?

#36

Post by MrPowers »

I am a Scala programmer & think it's a great language. Here are some arguments for why not Scala:

* Li's libs (os-lib, upickle, utest) have clean public interfaces, but most Scala ecosystem libs are hard to use, see the JSON alternatives for examples: https://www.lihaoyi.com/post/uJsonfastflexibleandintuitiveJS...

* The Mill build tool looks a lot better than SBT, but seems like everyone is still using SBT

* Scala minor version are binary incompatible, so maintaining Scala projects is a big pain. Upgrading Spark from Scala 2.11 to Scala 2.12 was a massive undertaking for example.

* Scala has tons of language features and lets people do crazy things in the code. Hard to win technical arguments with Scala geniuses that like using complicated language features.

* Scalatest is stil used by most projects and is annoying to use, as described here: https://github.com/lihaoyi/utest#why-utest. The overuse of DSLs in Scala is really annoying. Too many DSLs is another example of something I consider to be an antipattern, but there is no Scala community consensus on the responsible use of DSLs.

I'm optimistic about Scala. There are some folks that love the language and are continuously improving the ecosystem. Scala 3 will have to sell a better story about ditching legacy tooling and giving users a better default stack if it wants to compete with modern Go/Rust/Python.

Re: From First Principles: Why Scala?

#37

Post by occupy_paul_st »

playing_colours wrote: post #22
occupy_paul_st wrote: post #11

I definitely agree that many newer languages are strongly inspired by Scala, but I don't see a strong argument for why to choose Scala over one of a newer hybrid language. My own intuition is that these newer languages have had the benefit of being able to learn from Scala's mistakes. A lot of them have intentionally sacrificed some of the Scala's flexibility to be easier to learn and use. I found Scala to be an extr…

What newer hybrid languages besides Kotlin can cover the benefits you can get with Scala: a solid ecosystem (both for Scala and Java) for developing web applications, microservices, data processing, and good performance. Julia, Rust, and Elixir are all great, but popularity, ecosystem are not there yet.

I actually haven't seen a language that can do everything that Scala can do, so in a lot of senses I agree with you!

The alternative is to use multiple different languages to fill different niches. In theory this sounds suboptimal but I think it might actually be easier to learn multiple simpler languages than it is to learn Scala.

BTW according to PYPL: Swift, Kotlin, TypeScript, and Rust are now more popular than Scala.

https://pypl.github.io/PYPL.html

Re: From First Principles: Why Scala?

#38

Post by dominotw »

aynyc wrote: post #15

Is Scala used outside of Spark and Akka? Spark is my company chosen analytic engine, Scala was/is the main language for majority of the production workload. In the last two years or so, more devs are writing PySpark and SparkSQL jobs than Scala.

def mirrors my experience too. Vast majority of spark jobs were easily ported to sql/dbt and the remaining ones are in pyspark. I used to use a lot of scala spark in backend data processing in 2016 but now its almost down to zero.

scala is real big impediment to making data processing accessible to general public in your company. order of preference now at my company is,

1. sql 2. pyspark 3. java spark 4. scala spark

eg: shopify found that 70% of their pyspark could be converted to just sql https://shopify.engineering/build-production-grade-workflow-...

Re: From First Principles: Why Scala?

#39

Post by [deleted] »

aynyc wrote: post #15

Is Scala used outside of Spark and Akka? Spark is my company chosen analytic engine, Scala was/is the main language for majority of the production workload. In the last two years or so, more devs are writing PySpark and SparkSQL jobs than Scala.

[deleted]

Re: From First Principles: Why Scala?

#40

Post by dominotw »

MrPowers wrote: post #36

I am a Scala programmer & think it's a great language. Here are some arguments for why not Scala: * Li's libs (os-lib, upickle, utest) have clean public interfaces, but most Scala ecosystem libs are hard to use, see the JSON alternatives for examples: https://www.lihaoyi.com/post/uJsonfastflexibleandintuitiveJS... * The Mill build tool looks a lot better than SBT, but seems like everyone is still using SBT * Scala mi…

> Hard to win technical arguments with Scala geniuses that like using complicated language features.

I was on a team building good old crud apps using monads, monoids, categories, combinators, effects cats, seamless and bunch of other nonsense that i've now purged from my brain.

You could've easily mistaken our team for a programming language research group at a university.

This is literally the number one reason i would never choose scala. There is no upper bound to amount of stupidity one can indulge in. Our code was so convoluted that even intellij had trouble understanding what the hell was going on and would spit out compilation errors when there were none.

I now work with clojure team and i feel a sense of relief and weight taken off of my head from all the useless stuff i had to learn and use.

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