alvin's blog

A lot of people want to sell Scala as a functional programming (FP) language. That's fine, it certainly is, and FP has many benefits. But when I first started working with Scala I was just looking for a "better Java".

Personally, I grew tired of Java's verbosity. Ruby showed us a different way, and I loved it, but ... after a while I felt like many of my unit tests in Ruby wouldn't be necessary if the language had static types. I wished for a concise Ruby-like language with static types.

I just fired up my old 2006 MacBook Pro that runs Mac OS X 10.5.8, and it helped me realize why I don't like the Spaces feature in the newest versions of the Mac operating system: It used to be fun.

In case you were wondering about the status of the Scala Cookbook, we continue to roll along in the review process. We've found some reviewers who are helping to review the more difficult (or specialized) areas of the book, including chapters on the Play Framework, Actors & Concurrency, SBT, and others. While they're tackling those chapters, I'm working through all the previous review comments.

I ran into a situation this morning where I needed to use the Linux find command to (a) find all the MP3 files beneath my current directory and (b) copy them to another directory. In this case I didn't want to do a cp -r command or tar command to preserve the directory structure; instead, I wanted all of the files to end up in the same directory (so I could easily import them into iTunes).

Scala FAQ: How do I find the unique items in a List, Array, Vector, or other Scala sequence?

Use the distinct method. Here's a simple example using a List of integers:

scala> val x = List(1,1,1,2,2,3,3)
x: List[Int] = List(1, 1, 1, 2, 2, 3, 3)

scala> x.distinct
res0: List[Int] = List(1, 2, 3)

As you can see, res0 now contains only the unique elements in the list.