Scala as the new Java?

Question

I just started exploring Scala in my free time.

I have to say that so far I\'m very impressed. Scala sits on top of the JVM, seamlessly integrates with existing Java co

Answer 1

Well, the downside is that you have to be prepared for Scala to be a bit rough around the edges:

• you'll get the odd cryptic Scala compiler internal error
• the IDE support isn't quite as good as Java (neither is the debugging support)
• there will be breaks to backwards compatibility in future releases (although these will be limited)

You also have to take some risk that Scala as a language will fizzle out.

That said, I don't think you'll look back! My experiences are positive overall; the IDE's are useable, you get used to what the cryptic compiler errors mean and, whilst your Scala codebase is small, a backwards-compatibility break is not a major hassle.

It's worth it for Option, the monad functionality of the collections, closures, the actors model, extractors, covariant types etc. It's an awesome language.

It's also of great personal benefit to be able to approach problems from a different angle, something that the above constructs allow and encourage.

Answer 2

I don't think there are any downsides. Actually learning new language is very helpful for broadening your programming knowledge. You might gain from Scala such things as generic classes, variance annotations, upper and lower type bounds, inner classes and abstract types as object members, compound types, explicitly typed self references, views, and polymorphic methods.

Answer 3

Some of the downsides of Scala are not related at all to the relative youth of the language. After all, Scala, has about 5 years of age, and Java was very different 5 years into its own lifespan.

In particular, because Scala does not have the backing of an enterprise which considers it a strategic priority, the support resources for it are rather lacking. For example:

• Lack of extensive tutorials
• Inferior quality of the documentation
• Non-existing localization of documentation
• Native libraries (Scala uses Java or .NET libraries as base for their own)

Another important difference is due to how Sun saw Java and EPFL sees Scala. Sun saw Java as a product to get enterprise customers. EPFL sees Scala as a language intended to be a better language than existing ones, in some particular respects (OOxFunctional integration, and type system design, mostly).

As a consequence, where Sun made JVM glacially-stable, and Java fully backward compatible, with very slow deprecation and removal of features (actually, removal?), JAR files generated with one version of Scala won't work at all with other versions (a serious problem for third party libraries), and the language is constantly getting new features as well as actually removing deprecated ones, and so is Scala's library. The revision history for Scala 2.x, which I think is barely 3 years old, is impressive.

Finally, because of all of the above, third party support for Scala is incipient. But it's important to note, though, that JetBrains, which makes money out of selling the IntelliJ IDEA IDE, has supported Scala for quite some time, and keeps improving its support. That means, to me, that there is demand for third party support, and support is bound to increase.

I point to the book situation. One year ago there was no Scala book on the market. Right now there are two or three introductory Scala books on the market, about the same number of books should be out before the end of the year, and there is a book about a very important web framework based on Scala, Lift.

I bet we'll see a book about ESME not too far in the future, as well as books about Scala and concurrency. The publishing market has apparently reached the tipping point. Once that happens, enterprises will follow.

Answer 4

Beyond learning a new language, what's the downside to switching over to Scala?

Thinking, thinking, thinking..... nope, there is none :-)

Answer 5

The two, by which I mean four, biggest downsides I'm seeing are:

• Many working as developers in the professional community aren't trained and are unwilling to learn how to use a functional language, they won't even give it a go so they can understand why it's a better approach. This means you'll always be fighting an uphill battle getting adoption until it's mandated at the corporate level.

• RDBMS integration is still a bit spotty. Plenty of solutions, but nothing that really sticks out as becoming a standard. For me though, this might be an advantage rather than a disadvantage. JPA2 is a mess and causes more issues than problems it solves. Hibernate criteria queries aren't much better.

• IDE support is still lagging, but mostly in the area of debugging at this point. Code inspection is doing pretty good (at least in IntelliJ).

• You'll never want to write another line of Java again! Likely you'll want to punch a wall or break something when forced back into the awkward syntax of Java.

Answer 6

I was unshackled from the J2EE leash last year wanted to do something new after 12 years of Java in the enterprise building very large system for some of the worlds biggest companies.

I had tried Ruby on Rails in the past. After building a few sample apps I did not like the feel of it or the fact that I would have to write a ton of unit tests to cover stuff that is normally done by a compiler.

Groovy on Grails was my next port of call. I have to say I do like this but it suffers from the same dynamic typing problems as ROR. Don't get me wrong I am not putting Grails down as it is an excellent framework and I will still use it. Each has its own place IMO.

I then jumped on Scala and have now built a hybrid application based on Scala and Spring MVC. At first working with Scala is difficult but it gets easier and more productive the more time you put into it. I've reached a tipping point where I now want to invest time in Lift as well.

The combination of "Programming in Scala" and David Pollak's "Beginning Scala" books is good for learning the language, the latter with a less academic bent.

Scala is still young and has some way to go. I think it has a bright future and I see momentum is already picking up. Recently one of the creators of the Groovy language said in a blog post he would never have bothered designing Groovy if Scala had been around at the time.

I think some more work on better Java API integration/wrapping will give Scala the boost it needs to win more followers. The basic integration is there already but I think its could be polished a bit more.

Yes IDE support is there but it is basic at the moment. The powerfully refactoring support of Intellij is not there yet and I miss that a lot. The compiler + IDE support with a mix of of other plugins is not mature yet. I sometimes get very weird internal compiler errors caused by how Scala sits with JDO enhancement for the Goggle app engine. However these are little things that can be easily fixed. Early adaptation of new technologies and languages always comes with a little pain. But this bit of pain can produce great pleasure in the future.

If I look at the capabilities of Scala compared to early Java its miles ahead. When I moved from C++ to Java the JVM was not ready yet regarding scalability. There used to be lots of weird crash and burn JVM core dumps on various OSes. All of this has now been fixed in Java and the JVM is rock solid. Scals runs in the JVM so it has been given a massive head start on native platform integration. Its standing on the shoulders of giants!

After years of building and supporting enterprise applications my vote is for a language where a compiler can catch most of the non functional bugs before even unit tests are built. I love the type checking mixed with the power of functional programming. I like the fact that I am doing OO++.

I think the development community will decide if Scala is the future or not. The downside of adopting Scala now would be if it did not pick up momentum and adaptation. It would be very difficult to maintain an Scala code base with very few Scala developers around. However I watched Java come from the skunk works into the enterprise to replace C++ and it was all pushed from the bottom up by the developer community. Time will tell for Scala but currently it has my vote.