7 ms·

I agree that the criticism is fair. It does seem to come from someone with relatively little experience, but if anything, that makes it more valuable. Languages

by psuter 12y ago

I agree that the criticism is fair. It does seem to come from someone with relatively little experience, but if anything, that makes it more valuable. Languages need adoption and new adopters by definition have no experience. Regarding IDE support, which inevitably comes up when discussing Scala, an honest question: what are good IDEs for Ruby, Python, Clojure, JavaScript, Haskell, OCaml? Is there a good IDE for C++ besides Windows-only Visual Studio? For C? It seems that Scala always get compared to Java in that domain, but in my experience Java is the exception, not the norm. (Edit: I assume support for CLR languages is great too?)

bad_user 12y ago
If you compare IDE support with those languages, then Scala's IDEs are stellar. I would dare say that IntelliJ IDEA for Scala is better than Visual Studio.
- kasey_junk 12y ago
  It doesn't compare to Visual Studio with Resharper installed though.
akavel 12y ago
As to C++, Eclipse is good. (Not perfect, not certain if great, but it is good.)
- pkolaczk 12y ago
  And how long did it take Eclipse to get to that non-perfect-but-good state? Several years. When I checked 6 years ago, C++ support had been already there for a few years and was quite awful. And C++ type system is much less powerful than Scala's, so it should be theoretically much easier to provide good IDE support for.
  - lmm 12y ago
    The C++ template system is turing-complete and partial specializations are more or less equivalent to the way you do type-level programming in Scala with different priority implicits, so I don't see that it would be any easier to support than the Scala type system.
    - pkolaczk 12y ago
      If turing-completeness were the only criterion to judge programming languages, then we'd be all programming in Brainfuck. Indeed, C++ template system is turing-complete, as well as Scala's. But saying they are more or less equivalent is a complete misunderstanding. The main purpose of type-systems is to prove/disprove correctness-related properties of programs. The better the type system, the less frequently it rejects a valid program or accepts an invalid one. I could go on and list a number of features that Scala typesystem supports natively which C++ does not (e.g. type bounds, path dependent types, variance control, existentials, abstract types...), but there is no need to do that. There is one much bigger difference between them: C++ templates are not a first-class citizen of the C++ type system. They are just a (turing complete, but quite limited) macro-language bolted on top. Actually the compiler does not perform any typechecking of generic code. All the typechecking happens after macro expansion when generics are gone, and the typechecker needs to understand only concrete types. This is completely different than in Scala/Haskell/F#/C#/Java/OCaml typesystems, which can reason about generic types and can fully type-check generic code.
      - lmm 12y ago
        All true and all quite irrelevant to the problem at hand. An IDE does not need to know which properties a type system makes it easy or otherwise to prove. It just needs to understand the type system. And a useful C++ IDE absolutely does have to understand the template system and the way it interacts with the type system - maybe a compiler can get away with running them as two separate stages, but an IDE needs to do things with incorrect code as well as correct code.
        pkolaczk 12y ago
        "And a useful C++ IDE absolutely does have to understand the template system" I've never seen a C++ IDE that could fully type-check template-heavy library code before its actually used beyond just syntax checking and limited type-checking the non-generic types. This is something that can't be done just because of how C++ templates are specified ("duck-typing"), not due to an implementation detail in the compiler/IDE. This is also the reason why good error-messages from templates are so hard to make - type errors are detected at the concrete level (late), not at the generic level (early). This is going to change when C++ finally gets "concepts" and will be able to reason about generic types (but this would be still a very long way to something like Haskell or Scala has).
lemming 12y ago
what are good IDEs for... Ruby: RedMine/IntelliJ Python: PyCharm/IntelliJ Clojure: Cursive/IntelliJ JavaScript: IntelliJ + all JetBrains IDEs Haskell: Dunno OCaml: Dunno Is there a good IDE for C++ besides Windows-only Visual Studio?: CIDR undoubtedly will be, but it's still in beta right now. For C: AppCode Seriously, JetBrains just make fantastic IDEs.

by psuter 12y ago

bad_user 12y ago

If you compare IDE support with those languages, then Scala's IDEs are stellar. I would dare say that IntelliJ IDEA for Scala is better than Visual Studio.

kasey_junk 12y ago
It doesn't compare to Visual Studio with Resharper installed though.

akavel 12y ago

As to C++, Eclipse is good. (Not perfect, not certain if great, but it is good.)

pkolaczk 12y ago
And how long did it take Eclipse to get to that non-perfect-but-good state? Several years. When I checked 6 years ago, C++ support had been already there for a few years and was quite awful. And C++ type system is much less powerful than Scala's, so it should be theoretically much easier to provide good IDE support for.
- lmm 12y ago
  The C++ template system is turing-complete and partial specializations are more or less equivalent to the way you do type-level programming in Scala with different priority implicits, so I don't see that it would be any easier to support than the Scala type system.
  - pkolaczk 12y ago
    If turing-completeness were the only criterion to judge programming languages, then we'd be all programming in Brainfuck. Indeed, C++ template system is turing-complete, as well as Scala's. But saying they are more or less equivalent is a complete misunderstanding. The main purpose of type-systems is to prove/disprove correctness-related properties of programs. The better the type system, the less frequently it rejects a valid program or accepts an invalid one. I could go on and list a number of features that Scala typesystem supports natively which C++ does not (e.g. type bounds, path dependent types, variance control, existentials, abstract types...), but there is no need to do that. There is one much bigger difference between them: C++ templates are not a first-class citizen of the C++ type system. They are just a (turing complete, but quite limited) macro-language bolted on top. Actually the compiler does not perform any typechecking of generic code. All the typechecking happens after macro expansion when generics are gone, and the typechecker needs to understand only concrete types. This is completely different than in Scala/Haskell/F#/C#/Java/OCaml typesystems, which can reason about generic types and can fully type-check generic code.
    - lmm 12y ago
      All true and all quite irrelevant to the problem at hand. An IDE does not need to know which properties a type system makes it easy or otherwise to prove. It just needs to understand the type system. And a useful C++ IDE absolutely does have to understand the template system and the way it interacts with the type system - maybe a compiler can get away with running them as two separate stages, but an IDE needs to do things with incorrect code as well as correct code.
      - pkolaczk 12y ago
        "And a useful C++ IDE absolutely does have to understand the template system" I've never seen a C++ IDE that could fully type-check template-heavy library code before its actually used beyond just syntax checking and limited type-checking the non-generic types. This is something that can't be done just because of how C++ templates are specified ("duck-typing"), not due to an implementation detail in the compiler/IDE. This is also the reason why good error-messages from templates are so hard to make - type errors are detected at the concrete level (late), not at the generic level (early). This is going to change when C++ finally gets "concepts" and will be able to reason about generic types (but this would be still a very long way to something like Haskell or Scala has).

lemming 12y ago

what are good IDEs for... Ruby: RedMine/IntelliJ Python: PyCharm/IntelliJ Clojure: Cursive/IntelliJ JavaScript: IntelliJ + all JetBrains IDEs Haskell: Dunno OCaml: Dunno Is there a good IDE for C++ besides Windows-only Visual Studio?: CIDR undoubtedly will be, but it's still in beta right now. For C: AppCode Seriously, JetBrains just make fantastic IDEs.