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Scala is more flexible (for better or worse) and less verbose (for better or worse). Because of this, it's possible to be much more expressive in Scala and it'

Scala is more flexible (for better or worse) and less verbose (for better or worse). Because of this, it's possible to be much more expressive in Scala and it's possible to be much more terse/obtuse. I like Scala's powerful type system -- I just have a hard time reading most other people's Scala. If you're sure you can get a consistency of style and approach in Scala among your team, sure, by all means. But if you believe that you're likely, at least in the short term, to have stylistic inconsistencies among your team, I'd lean a little more towards Java (just on "worse-is-better" principle).

scala8 11y ago
What do people mean when they say "powerful type system"? Does that mean it could potential be a downward spiral where everyone creates their own DSL? I use Ruby on Rails and Django - and in ruby and python, it's interpreted on the fly. How will a type system, let alone a "powerful type system", help improve ruby or python's web apps?
- ubertaco 11y ago
  By "a powerful type system", I mean a type system that allows you to flexibly express more-complex constraints in a way that the platform (either compiler or runtime) will catch. For example, Javascript's type system (such as it is) is not, in my opinion, as powerful as Java's -- since there's no compile-checking and the runtime coerces stuff all over the place and does basically no checking at any point. Python's is somewhat better: there's runtime-checking, but it's duck-typed -- so you could call some array methods on an instance of, say, "FootballField" just because the FootballField has a "__len__" property and the runtime wouldn't catch it. Java's type system is a tiny bit more powerful -- the compiler does a lot of checking for you (so you can enforce that a method must take an array or a List<something>), but it's not as flexible (until JDK8, there was almost zero type inference, so you had to be super-explicit everywhere). Scala's type system is more powerful still; traits allow you to describe similar classes in a duck-typed-esque way (without the classes themselves having to opt-in), and there's really good type inference. I'm not an expert in Scala, so I could be wrong about some of its features in particular, but that's the sort of thing that I mean by "powerful type system".

scala8 11y ago

What do people mean when they say "powerful type system"? Does that mean it could potential be a downward spiral where everyone creates their own DSL? I use Ruby on Rails and Django - and in ruby and python, it's interpreted on the fly. How will a type system, let alone a "powerful type system", help improve ruby or python's web apps?

ubertaco 11y ago
By "a powerful type system", I mean a type system that allows you to flexibly express more-complex constraints in a way that the platform (either compiler or runtime) will catch. For example, Javascript's type system (such as it is) is not, in my opinion, as powerful as Java's -- since there's no compile-checking and the runtime coerces stuff all over the place and does basically no checking at any point. Python's is somewhat better: there's runtime-checking, but it's duck-typed -- so you could call some array methods on an instance of, say, "FootballField" just because the FootballField has a "__len__" property and the runtime wouldn't catch it. Java's type system is a tiny bit more powerful -- the compiler does a lot of checking for you (so you can enforce that a method must take an array or a List<something>), but it's not as flexible (until JDK8, there was almost zero type inference, so you had to be super-explicit everywhere). Scala's type system is more powerful still; traits allow you to describe similar classes in a duck-typed-esque way (without the classes themselves having to opt-in), and there's really good type inference. I'm not an expert in Scala, so I could be wrong about some of its features in particular, but that's the sort of thing that I mean by "powerful type system".