I've gone back and forth between dynamic and static and strict and loose in every combination and I don't find the dynamic/loose to be particularly freeing anymore. The problem is you can't really rely on anything. It doesn't so much as solve the problem that Crockford is talking about, it just moves it somewhere else. You don't have to refactor but you're going to end up with two (or more) different things that exist at the same time instead of one.
> Look at the mocking libraries for JavaScript. They're sooooooooo much easier to write than anything for classical languages because it's so easy to do in JavaScript.
This is a great point and it's a perfect example of the advantages and the horrors of the JavaScript model. A mock is supposed to be an object that does something completely different (typically nothing) but otherwise looks and functions like the real thing. Maybe just in one slight exceptional way. JavaScript makes this easy. But it also makes it easy to make those same changes outside of mocking and tests and that is just debugging hell waiting to happen.
And note I'm specifically calling out JavaScript. Other dynamic languages IMO haven't provided the same benefits because they're still following old models.
When you truly grok JavaScript and stop trying to use it like your other languages it really starts to shine. It's not perfect but it is different.
That does not follow from what you quoted, and what you quoted is a non-sequitur to start with.
What you're raving about can be achieved just as easily in any dynamically typed language. Hell you probably get 80~90% of that in a structurally typed language (OCaml objects, Go).
> In JavaScript you can build objects on the fly.
Which you can do in many other languages, including statically typed ones. Here's an object in Ocaml:
# let s = object
val mutable v = [0; 2]
method pop =
match v with
| hd :: tl ->
v <- tl;
Some hd
| [] -> None
method push hd =
v <- hd :: v
end
> The problem with 'class' in ES6 is that it will prevent people from learning this new, easier, faster, simpler way of working because instead they just bring the classical baggage to JavaScript.
That's patent nonsense, not to mention ES6's class shortcuts apply to object literals as well, the only thing the class statement does is remove the bullshit and mostly useless boilerplate Javascript demands when creating a reusable prototype due to it being a garbage language, and its "prototypal" object system being there not because it's good and going to save the masses but because it was the easiest way to have an object system working in a week. It's just a sad and pitiful shadow of Self's object system from which it draws so little you have to know the relation's there to find it.
Getting stuff done until the code base grows and others have to adapt or build up on the code you've written : the idea of bringing in structure is to encode knowledge about the problem you are solving and keeps it all maintainable (admitted, if done right).
> In C++ (and similar classical languages) in order to be able to pass in different implementations of a class you need to create a base class or interface.
And that is a good thing IMHO, see above. However I agree that, particularly in C++, an interface definition is very verbose. Unfortunately it has no pure Interface concept.
That's basically what they are.
> You can still create anonymous objects quickly, and use any object as prototype for another.
Hell you can create anonymous objects even faster with ES6 since object literals also get the short method notation and computed properties.
You can do that in a language with classes and even one with optional types e.g. you can use jasmine perfectly well to mock typescript objects (because they are just JavaScript dynamic objects)
" I have to make classes and meta classes and all kinds of other indirection just so I can make an Event system that is generic."
I remember reading Gilad Bracha saying somewhere that enabling exactly this kind of system was exactly one of the use cases for Dart which is class based with optional types. You can have your cake and eat it too!
function base(spec) {
var that = {},
member,
method = function() {
// spec, member, method
};
that.method = method;
return that;
}
function derived(spec) {
var that = base(spec),
member,
method = function() {
// spec, member, method
};
that.method = method;
return that;
}
That's also very memory inefficient. The method function gets made for every instance. With prototypes there would be only 1 function in memory. This stuff matters at scale.
You've got a gig of ram in your pocket. Memory doesn't matter for 99.99999% of apps. The memory taken by your objects isn't where your memory goes. It goes to images and other big stuff. A few extra bytes per object isn't going to kill you. Optimize for programmer time not memory, especially not in memory on things that don't matter.
Why are you using "instanceof". The whole point of inheritance is you shouldn't have to ask. If you are asking your doing it wrong
In C++ (and similar classical languages) in order to be able to pass in different implementations of a class you need to create a base class or interface. You don't need to do this in JavaScript.
In JavaScript you can build objects on the fly. In fact he goes on to say
> so I used to think that the important thing in JavaScript was prototypal inheritance I now think it is Class Free object oriented programing. I think that is JavaScript’s gift to humanity. That’s the thing that makes it a really interesting important language, is that it did that. That we can use functions in order to create objects and it simple and elegant and powerful and fast...
And it's true. Look at the mocking libraries for JavaScript. They're sooooooooo much easier to write than anything for classical languages because it's so easy to do in JavaScript. In my own experience I have a mutli-user networking system written in JavaScript and a library in C#. To reimplement the same things in JavaScript in C# is a huge amount of code bloat. I have to make classes and meta classes and all kinds of other indirection just so I can make an Event system that is generic. In JavaScript that's 2 or 3 lines
That we don't actually need all the structure to get shit done is what people are finally coming to realize.
The problem with 'class' in ES6 is that it will prevent people from learning this new, easier, faster, simpler way of working because instead they just bring the classical baggage to JavaScript. That's in fact what most programmers from classical languages do. It's what I did for years until I started actually grokking JavaScript. ES6 "class" will only make it take longer for people to actually get pass their old ways.