Well done on posting this! it's a great way to learn and share your experience of learning new languages and get feedback. (just take the comments by face value without any sentiments, you should learn from them, not make them discourage you, ignore "my eyes are bleeding" type of comments or "Scala is sooo complexxx" unless they have some really constructive criticism in them...)

One tiny cosmetic suggestion that popped to my eyes since you asked for comments :)

    def parseInputRange (s: String): Array[Int] = {
      val ab = s.split(":").map(_.toInt)
      (ab(0) to ab(1)).toArray
    }

the `to` method is inclusive on the end of the range, so it is the same as until x + 1

Good luck!

That has been removed from the Scala standard lib and is now distributed separately. I am unsure how well it will be maintained by the community. As the other commenter said, parboiled2 is a good choice using macros and it is lightning fast. A lighter weight, runtime choice that was released recently is fastparse[0].

0 - https://github.com/lihaoyi/fastparse

The Parboiled2 framework is often used for building parsers.

> The "Scala is slow to compile" meme needs to die in a fire.

Martin Odersky has commented many times [1] that scalac won't be as fast as javac. The only link I could find right now is http://stackoverflow.com/questions/3490383/java-compile-spee... which is rather old; but I remember watching more recent videos (< 2 years old) where he makes the same points.

> and much faster then my current gig's much smaller Gradle based Java 8 project

Yeah I call BS on that.

Scala's slow compilation doesn't really bother me that much but Java compiles at least ten times faster.

> The "Scala is slow to compile" meme needs to die in a fire.

Well said.

Additionally, I think people often forget that the same JVM tuning parameters available for production deployments are available for Scala compilations. These can make a huge difference in build times, especially since the default JVM parameters are understandably conservative.

> At my last job we had a large Scala codebase and it compiles faster then our similarly sized C# project, and much faster then my current gig's much smaller Gradle based Java 8 project

I never looked at that way before. We were a shop that used scala and Ruby.

So many of us come from interpretted languages and are used to code and tests reloading with no downtime. How does scalac match up to C# and Java compilation? I'd be interested in seeing the numbers.

Thank you!

scalac is definitely slower than javac, but I do wonder if half the complaints about speed are from people who don't realize you can leave SBT running but rather do an "sbt compile" every time and end up waiting for JVM initialization.