I would pay good money to see Paul Philips' reaction to the sentence
> "the biggest benefit with Scala is correctness."
...before the author goes on to say
> "When I say correctness, I mean the ability to easily and consistently write code that works as inteded (not the academic definition of correctness)"
As someone who used to work on automatic proof of correctness systems, that irked me too.
It's quite reasonable to have a language where certain classes of errors cannot be generated from the source code. There are languages which can reliably detect or prevent subscript out of range errors, null pointer errors, dangling pointer errors, and race conditions. (C and C++ detect and prevent none of the above, which is the cause of most of the troubles in computing.) That's not full correctness; it's just language safety. It means you can't break the language model from inside the language. Most of the "scripting languages" have this property, or at least are supposed to.
Scala takes the null pointer issue a bit more seriously than most languages. That's good, but not enough to justify a claim that it offers "correctness".
> "the biggest benefit with Scala is correctness."
...before the author goes on to say
> "When I say correctness, I mean the ability to easily and consistently write code that works as inteded (not the academic definition of correctness)"