Wasabi – A Sinatra-inspired web framework for Kotlin

http://blogs.lessthandot.com/index.php/WebDev/ServerProgramming/wasabi-a-sinatra-nancyfx-inspired

by chrissie1 • 13 years ago

21 23 13 years ago

blogs.lessthandot.com

microtonal2• 13 years ago

I wrote some toy programs in Kotlin, can anyone who used it for serious projects weigh in on how it compares to e.g. Java 8?

hhariri4• 13 years ago

With the disclaimer out the way that I work for JetBrains, we are using it internally for several projects and some parts of our tools, including for instance the LiveEdit functionality in WebStorm is written in Kotlin. In terms of comparing to Java, yes Java 8 adds lambdas but Kotlin drastically reduces the amount of code required and adds several other features that are not in 8.

microtonal2• 13 years ago

I certainly think there is a place for a language that does not have the complexity of Scala, but reduces the boilerplate of Java. I also liked the support of non-null types in Kotlin.

qwerta3• 13 years ago

I wrote about 10kloc in Kotlin for internal testing framework. It is heavily multi-threaded and Kotlin aced here (compared to Scala).

Java8 brings lot of legacy stuff. It feels like authors just wanted to add 'functional' on feature list. No type inference or named arguments.

I think it is better to compare Kotlin to Groovy or Scala. In both cases it is simpler and more elegant language.

I found two problems with Kotlin:

Not mature yet. It is surprisingly stable and bug free (compared to Scala just 4 years ago). But some features are not designed yet and are missing (for example getters handling). Those will be added in some future milestones. Also I had to write some boiler plate code which should be in standard library.

Nullability handling is strictly required. Most of classpath API is already annotated, but I had to annotate external libraries I am using.

virtualwhys2• 13 years ago

Interesting, in what ways is Kotlin more elegant that Scala?

pron6• 13 years ago

I, too, have high hopes for Kotlin. It seems to achieve what I'd hoped Scala would but ended up failing miserably.

There's a lot of merit to the "Java philosophy": a gradual progression of what most programmers expect in a language. Google, for one, seems to have adopted the Java philosophy wholeheartedly in its new languages Go and Dart.

Kotlin is certainly in that camp: a gradual progression that will make programmers happier yet won't turn their world upside down. It's simply a better Java. So while Scala unfortunately evolved from being a better Java into the mother of all kitchen sink languages (assuming, of course, that your kitchen feeds a whole military base and has sinks the size of hot tubs), trying to cram Java, Haskell, Lisp and Javascript into a single compiler (I find it hard calling Scala "a language"; it's more like a compiler that compiles code written in any of several languages), Kotlin takes a few steps back and comes up with a coherent philosophy.

I think 99% of Scala users will find Kotlin to provide 100% of their requirements, and at a much reduced complexity and mental load. So Kotlin, I think, is not only a better Java, but a better Scala.

Yet, I think Java 8 will be the game to beat, for Kotlin as well as Scala. Java is hugely popular, and those that haven't migrated to other JVM languages so far, might be less likely to do so when Java 8 comes out. With lambda expressions and traits – the two killer features that attract many to Scala when it first came out – it gives Java a nice boost. Sure, Kotlin feels more like a fresh start, and has some other necessary features (properties), but will those be enough to switch people away from Java?

I think that one of the great achievements of Kotlin's design, though, is that the transition could be very gradual. Kotlin places a very strong emphasis on Java interoperability (leaps and bounds better than Scala's) and unlike Scala, Kotlin code is easily read by Java programmers. So teams would be able to easily replace individual Java classes with Kotlin code.

RazvanPanda2• 13 years ago

Why was the Issues tab removed? http://i.imgur.com/9jCrGY8.png

hhariri4• 13 years ago

We don't use GitHub issue tracker. Issues are tracked with YouTrack here:

http://hhariri.cloudapp.net:8080/issues/WA

Support is on Google Groups:

groups.google.com/forum/#!forum/wasabifx

RazvanPanda2• 13 years ago

Ah, I missed that in the description, thanks for reply.

pron6• 13 years ago

I see that you're using straight-up Netty as the http server. Why did you choose to take this path rather than use a servlet container (Jetty, Tomcat)? Are there performance advantages?

hhariri4• 13 years ago

I wanted the minimal viable that worked and proved concept and direction of API and then build on it. And while Netty seems to be seriously good performance wise , I will most likely add a layer to allow use of any servlet container. The dependency on Netty is minimal. Basically only one file with is the Request handler.

bhauer• 13 years ago

To what the author has said, I will add that in terms of performance, Netty is currently faster than the fastest production Servlet containers [1]. Presently, Undertow (the web server for the upcoming WildFly application server, which will have a Servlet container) is the only platform providing slightly faster request-processing performance. Until WildFly is production-ready, Resin is the highest-performance Servlet container I am aware of.

[1] http://www.techempower.com/benchmarks/#section=data-r6&hw=i7...

Wasabi – A Sinatra-inspired web framework for Kotlin

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