I see Java 8 more as an even better gateway drug to Scala than Java 6, so I expect adoption to accelerate. (Then again, I'm biased.)
Java-8-the-language is a pretty timid comeback. Functional programming is not just about lightweight syntax for function literals and some more type inference for polymorphic method calls. That's just the start.
An FP language should also:
* encourage immutability;
* make it easy to write and refactor code that uses combinators (generic higher-order methods) --> local type inference is essential (IDE support for type inference doesn't help, unless other refactorings automatically update the synthetic type annotations)
* encapsulating logic in functions rather than using dynamic dispatch (where it makes sense), naturally leads to pattern matching.
Also, Scala has great support for asynchronous/event-driven/reactive programming through extensible for-comprehensions, and the macro-based scala-async framework.
Then there's the OO side: interfaces with default methods are much more limited than traits,...
I'm very excited about the VM improvements and the potential of more functional libraries in our eco-system, though!
Having recently worked with a project employing Java 8, I whole-heartedly agree. The FP in Java 8 is so crippled as to be useless. Every time you use a lambda, you need to worry about checked exceptions and wrapping and unwrapping them. Also there is no Unit type, so you have to add `return null` everywhere.
Moreover, the Java collection library is now a hodge-podge of ancient cruft haphazardly mixed with a half-hearted FP interface. Java seriously needs to drop pre 1.5 compatibility, and revamp the whole API.
Java-8-the-language is a pretty timid comeback. Functional programming is not just about lightweight syntax for function literals and some more type inference for polymorphic method calls. That's just the start.
An FP language should also:
* encourage immutability;
* make it easy to write and refactor code that uses combinators (generic higher-order methods) --> local type inference is essential (IDE support for type inference doesn't help, unless other refactorings automatically update the synthetic type annotations)
* encapsulating logic in functions rather than using dynamic dispatch (where it makes sense), naturally leads to pattern matching.
Also, Scala has great support for asynchronous/event-driven/reactive programming through extensible for-comprehensions, and the macro-based scala-async framework.
Then there's the OO side: interfaces with default methods are much more limited than traits,...
I'm very excited about the VM improvements and the potential of more functional libraries in our eco-system, though!
[edited for formatting]