I don't think the assertion that JavaScript's prototype-based OO is more expressive because it lets you fake partial implementations of class-based OO with relative ease is true.
Now, if we could reliably implement class-based OO systems comparable to, or even better than, those found in Java, C#, C++, Python, Ruby, and Smalltalk, for example, then maybe we could say prototype-based OO is more expressive.
However, all we end up with are multiple half-assed (for a lack of a better term) approaches, each of them critically incomplete in one way or another, and often incompatible with one another, too. This creates the integration and maintenance headaches that should be more than apparent to anyone who has worked on any sizable JavaScript code base.
In fact, I think we see the opposite in reality. It's much more effective to implement prototype-based OO systems using class-based OO languages. We see exactly this with the major JavaScript implementations (i.e., prototype-based OO systems) today being written in C++.
So prototype-based OO fails to deliver both in terms of expressiveness and maintainability. It is just a worse technique, when considering the facts. Trying to pretend it's good at things it clearly isn't good at doesn't make much sense to me.
And there's no "language war". C and C++ do the vast bulk of real work today. No other languages today can compare to them, and the ones that try still depend very heavily on one or both.
> So prototype-based OO fails to deliver both in terms of expressiveness and maintainability. It is just a worse technique, when considering the facts. Trying to pretend it's good at things it clearly isn't good at doesn't make much sense to me.
You are focusing too much on prototype OO.
The models offered by Smalltalk, Beta, CLOS, Haskell and quite a few others are different approaches to the classical model known to the average developer.
This is the main problem in the "offshore everything model" that looks for cheap dumb developers able to work like cogs and not required to think.
> And there's no "language war". C and C++ do the vast bulk of real work today. No other languages today can compare to them, and the ones that try still depend very heavily on one or both.
When I started developing (1986), C was just another language that most people did not care about. In fact I only cared to write some C code around 1993.
The current situation came to be due to UNIX's influence in the enterprise and the fact that any developer worth his salary isn't not going to rewrite the full stack from zero.
It has nothing to do with their suitability for OO development.
I focus on JavaScript and its attempt at prototype-based OO because there's a huge amount of such code that already exists, and more is being written each day. It poses practical problems affecting many developers today.
While Smalltalk, BETA, CLOS, Haskell and other languages do have their own approaches, we really don't see them being used anywhere near as much as JavaScript, C++ or Java are. Realistically, Haskell is seen rarely outside of academia, aside from some very isolated projects. C++, and then Java, put an end to any real momentum that Smalltalk had gained during the 1980s and 1990s. BETA and Common Lisp see very little usage these days, too. They are pretty much irrelevant in a discussion of applied software development.
I wouldn't attribute C's success and C++'s success purely to UNIX or enterprise users. In fact, many of the most significant users are open source projects. They're successful because what they offer is what developers need. Flexibility, performance, portability and in C++'s case, sensible and practical object-orientation. People go out of their way to use C and C++, even when it isn't as practical (such as under Windows and various embedded platforms). This is quite different from people using JavaScript, which is used mainly because it's the only practical option available for browser-based scripting.
That's true, but I just have to ask: so what? I, for one, don't subscribe to the theory that popularity equals quality. Although both C and C++ are immensely popular in terms of code written in them that doesn't mean they're the last word in language design.
> No other languages today can compare to them, and the ones that try still depend very heavily on one or both.
I don't understand what you mean by "compare to them". If you mean in terms of features - sure there are languages more advanced. If you mean in terms of popularity then I can only say I find such comparisons meaningless.
> Now, if we could reliably implement class-based OO systems comparable to,
> or even better than, those found in Java, C#, C++, Python, Ruby, and Smalltalk,
> for example, then maybe we could say prototype-based OO is more expressive.
We can do this (modulo "reliably", which I don't understand what you mean by) and that's the problem. You yourself explain this:
> However, all we end up with are multiple half-assed
That's exactly the case. Java, C++, Python and Ruby are extremely incompatible with each other. No wonder that JS implementations of ideas taken from those languages are still incompatible - although less so than originals between themselves. It's also not that strange that they are incomplete - given that everything you'd like to do in class-based system you can do with prototypes there is simply no need for frameworks being complete.
Can you post a few examples of what is possible in Java and not possible in JavaScript?
Also remember that language designers can alter syntax to better support their systems, so we need to exclude syntax from comparison.
> It's much more effective to implement prototype-based OO systems using class-based OO languages.
I don't know if it's impossible, but your examples are flawed. Of course you can write any language in any language, like JS VMs are. But that's completely different matter, I was talking about using the language itself in a prototype based manner. I suspect that, due to static and low-level nature of classes in C++ it's completely, utterly impossible to replicate JS object system inside C++. That you can write interpreter that implements this system is obvious and not interesting at all.
As a counter example, in Python you could, with careful use of metaclasses and implementation details of classes and objects create objects whose methods lookup order and semantics of would be the same or close to those of prototype based JS - in the language itself.
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Your arguments fail to prove that prototype based-ness somehow fails. It does not, in itself, fail in any way. As I wrote above, show what can be done with classes (single inheritance model) that cannot be replicated using JS or better IO prototype semantics - that would be convincing. The fact that JavaScript development is a mess - I won't deny it - proves nothing about prototypes and only a bit about JS.
By the way, have you tried Haskell, OCaml or F# and Erlang?
Now, if we could reliably implement class-based OO systems comparable to, or even better than, those found in Java, C#, C++, Python, Ruby, and Smalltalk, for example, then maybe we could say prototype-based OO is more expressive.
However, all we end up with are multiple half-assed (for a lack of a better term) approaches, each of them critically incomplete in one way or another, and often incompatible with one another, too. This creates the integration and maintenance headaches that should be more than apparent to anyone who has worked on any sizable JavaScript code base.
In fact, I think we see the opposite in reality. It's much more effective to implement prototype-based OO systems using class-based OO languages. We see exactly this with the major JavaScript implementations (i.e., prototype-based OO systems) today being written in C++.
So prototype-based OO fails to deliver both in terms of expressiveness and maintainability. It is just a worse technique, when considering the facts. Trying to pretend it's good at things it clearly isn't good at doesn't make much sense to me.
And there's no "language war". C and C++ do the vast bulk of real work today. No other languages today can compare to them, and the ones that try still depend very heavily on one or both.