Saturday, May 17, 2008

My First Scala Presentation

I gave my first talk on Scala today, to my team at NYSE. It was an entirely informal, BYOL (Bring your own lunch) talk that I hadn't prepared for at all (I was hoping someone else would speak, but since no one else ever does, its always me, prepared or not). Anyway, there are some lessons learned from the talk.

The talk didn't really go over that well, and mostly because I didn't hit them hard with a great example up front. Next time I will. I finally won them over when I showed a List example, which I'll show here.

Say you want to create a List of integers containing the elements 1, 2, and 3. In Java there are a few ways to go about it, none of them very easy. I'll start with the most common example.

List<Integer> ints = new ArrayList<Integer>();

Like I said, there may be easier ways to do this, but I don't think many people will argue that this would be by far the most commonly used approach. There are several things wrong with it.

  • It's about a billion characters long.
  • The redundant type information in the first line is so frustrating.
  • The next three lines of code are almost identical.
  • The semi colons are pretty much pointless.

Here's how you do the same thing in Scala.

val ints = List(1,2,3)

Thats it.

  • Its 20 characters total (not including the unneeded spaces). 20 characters vs. A Billion! I pick 20.
  • There is no need whatsoever to put an absurd amount of type information. The compiler is perfectly capable of figuring that out thank you. As are humans; any second year college student could tell that thats a list of integers. Heck, any 7 year old could too.
  • There is absolutely no redundant code here.
  • There are no semi colons.
This example has probably been posted on the internet about a million times by now, and its not the point of this post. The point is this: If you want to give a talk on a language, hit the audience hard with a solid example immediately. Don't dilly-dally and give examples that are only slightly different than their current language and then give them the good stuff. You'll meet too much opposition up front. I thought I was doing them a favor by easing them into Scala but what really happened was quite the opposite. For some terrible reason Java developers are quite territorial. I was providing fuel for them to say, "I'll stick with Java."

Next time, I give the good example up front, then transition to the easy stuff once I've peaked their interest, and then make sure to finish up with a solid example too. And of course next time I'll be quite a bit more prepared.

Ok. Thats the gist of what I was wanting to talk about, now some sideline commentary.

One particularly odd complaint IMO was that most of this was just syntactic sugar. First off, I whole-heartedly disagree, but I can see why some people could incorrectly think that way. My colleague happily responded:

If you think it's just syntactic sugar, then I have a perfect language for you. It only contains 2 characters, 1, and 0. Using anything else, well thats just syntactic sugar.
Of course anyone can think that higher level languages are just prettier syntax, but they would be entirely missing the point. The point is to not have our primitive human minds bombarded with useless information so that we can better and more easily understand the meaning of each line of code. Thats not sugar, thats evolution, baby.

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