Twitter/Ruby/Scala/Blah

For some reason I feel compelled to chime in on this debate. I like both languages. I like Scala more, but Ruby is fun.

(Reader Beware: This post was written in one pass with little to no editing.)

I don't like how people get all steamed about their languages, as if it's part of them. But, if used properly, this energy can be channeled into creating better languages, so I guess its a necessary evil. The problem is, it not often used properly. Developers seem to just get mad at each other instead of talking through things civilly, and thinking critically and objectively. This is nothing new, and nothing that hasn't been said a thousand times I'm sure, but I think serves well as a nice introduction.

Maybe the problem is that so many of the elements of programming languages are based on feel, as opposed to simple fact. I wish we'd all think more logically and have nice intelligent debates, and I wish we could support our arguments more with fact.

Now for a debate. I was tweeting with Daniel Spiewak who said,

"Obie has once again decided to completely miss the point. Twitter's legacy code is bad *because* of Ruby, not in spite. The experiences described by @stevej and @al3x precisely mirror my own: it isn't impossible to write large, maintainable Ruby...just hard."

I asked him if he could elaborate on "because of", and to that he replied,

"Ruby makes it *hard* to architect a large infrastructure and to keep it maintainable. I think that dynamic typing is part of the problem, but not all of it. Possibly the way the module system works? It isn't impossible to do large apps in Ruby (as Obie and Ola remind us), but it takes more effort and more discipline. Java and Scala both make this sort of large scale code base much easier to create and maintain."

Now, I don't necessarily disagree with that (and recall that I do like Ruby). But I'd like to point out that I've been on a lot of Java projects that were completely unmaintainable. You could easily call them absolute disasters. In fact, the majority of the Java projects that I've been on have been disasters (yes, yes get your laughs in and tell me that its my fault...but its not. I did a lot to help those failing/flailing projects). Maybe that's because I've picked bad projects, and haven't many changes to work with great teams on applications built correctly from the start.

But, I think that emphasizes my point a little. Who has? How many projects are built correctly from the ground up, by talented, disciplined developers? I'd say not many. Most developers are horrible, and the language wouldn't make a shred of difference. And for those developers who are really good, the language probably doesn't make that much difference either. A group of solid developers could easily build something far more maintainable in Ruby than the garbage developers who are writing in Java.

But can those same developers build something more maintainable in Java or Scala? I think it depends on a whole number of things (listed at the end of the post). If there's a good chance of turnover on the project, then you probably want something with type information in the code because it serves so well as documentation. But if there's little chance of turnover it probably doesn't matter.

That said, even with turnover, because Ruby is inherently higher level that Java its probably more easy to maintain. Java is just not a good language anymore, it has not stood the test of time. It came about to fix some problems with C++, and had a syntax that appealed to those developers, but that was 1994. It has not evolved. Ruby is so much more expressive than Java that the lack of type information probably doesn't mean much at all.

Scala on the other hand, probably no contest for large projects. I think Twitter made the right decision. They get the type safety, the type documentation, and the high level expressiveness all together. I do like Ruby a lot, but Scala just feels better to me, and feel is very important, even if its not measurable.

But all that could be wrong. How many large projects have actually been built in Scala? Few. I said in the beginning that I want people to think critically and objectively. It would be nice if we could base some of these debates on fact. Are there any facts out there that large Java projects are more maintainable than Ruby? There may well be, and if so, we should get that information out there. Then again, there may be documentation that supports the opposite.

So I'm not really calling for comments here, though they are always welcome. What I am calling for is experiments, evidence, observations, or facts that support that one language is more maintainable than the other for any sized project.

Here are some questions whose answers would be helpful (in no particular order):

• What language was used?


• What was the size of the project:
  
  
  
  1. LOC? Production and Test code.
  
  
  2. Number of developers?
  
  
  3. Number of testers?


• How long did the project take?


• What was the amount turnover?


• What was the experience level of the developers?


• The amount of time the team has been together?


• The amount of time the developers have spent with the language used?


• Type of project? (Obviously if the language chosen was a horrible choice for the project, it makes a difference)

This information is probably pretty difficult to come by. The lack of it shouldn't impede intelligent debate, but the presence of it could help us as a community.