I was always wondering why HN crowd is ok with TS and so prejudiced against Dart - Dart has NG2, await async in older browsers and good tooling (webstorm, vscode) and much saner package system. When doing lot of small web apps - it's easier to mantain.
At least in my view, there's a couple of big things: Dart doesn't introduce that many advantages over JS for all of its differences, and TS introduces many of them with a smaller diff; there's also the presentation of it—Dart was originally presented as a wholesale replacement of Dart, to ship in all browsers, the language more or less as a fait accompli, which rubs plenty of people the wrong way.
> Dart doesn't introduce that many advantages over JS for all of its differences
As someone with experience in both languages, I could not disagree more.
> Dart was originally presented as a wholesale replacement of Dart
I think you meant replacement of JS here. I guess it depends entirely on what you think of JS as a language. I, for one, would rather a language that fixes core issues with JS, instead of just being a superset of JS.
> I think you meant replacement of JS here. I guess it depends entirely on what you think of JS as a language. I, for one, would rather a language that fixes core issues with JS, instead of just being a superset of JS.
If I were aiming to replace JS, I'd fix what Dart does, but I wouldn't stop with merely fixing what Dart does.
Dart, despite being an entirely new language, has a less expressive type system than TS. It's transpiler (and it's VM) also does no optimisation based on the type system, instead heavily relying on the JIT to infer what the types already imply (e.g., it would be nice to do things like LICM at compile-time).
As for the rest of your comment, I'm with ya. I guess they're reasoning behind that was they thought a lot of development would start out untyped with additional types added as development progressed. I think that assumption didn't pan out, at least that's not how I do it.
"Q. But don’t you need sound typing information to get high performance?
Sound types can help with performance but aren’t essential. What we need are uniform, simple semantics. Modern VMs can use actual runtime behavior as a valuable signal for optimizations."
Typescript also has structural types, like Go and OCaml, which many people find nicer than nominal types. Structural types mean if I have an interface Blaz with two methods Foo and Bar, if I have an object MyObject with Foo and Bar methods of the same types then my object counts as a Blaz, while nominal types mean I have to write something like MyObject extends Blaz.
That's how dart2js works today but the goal for Dart 2.0 is to move to a sound type system. The beginning of this is available today as "strong mode" and the Dart Dev Compiler.
Your view seems to be from someone who hasn't used Dart extensively, because no one who had would minimize its advantages this way. Being different from JS is the whole point. Dart introduces all the advantages of TS and more, while leaving the baggage and bullshit of JS behind.
What do you mean "fait accompli"? Was the Dart team supposed to give the community a chance to abort the language from existing, and the community was upset that it was completed and published without the input of people who wanted it not to be?
>Was the Dart team supposed to give the community a chance to abort the language from existing
No, he means that the Dart team was supposed to solicitate opinions on how to build Dart and what the best objectives for it would be, but instead they showcased it in "almost done" form, and only then tried to attract a community.
This. While yes, it was a long way from "standardised" and a lot changed between what Google initially published and the Ecma standard, many fundamental design decisions were made internally and there was never any real influence externally over that. Those are fundamental design decisions where to change them you essentially need to start from scratch.
The other big problem was that it was done with the VM being a major part of the project with the intent of getting it into Chrome, obviously without having talked that much with several of the people who have significant influence over such things in (then) WebKit, even those within Google. That the VM was going to be outright objected was entirely predictable.
TS seemed more willing to interoperate with the rest of the JS ecosystem - gradual typing, external .d.ts files for popular libraries, working with existing build tools and module systems. Whereas Dart felt like more of a gated community where you were expected to do things the Dart way and there wasn't much support for traditional JS.
> working with existing build tools and module systems
I'd say they replaced it with a better tool, pub.
The one good argument you have there is .d.ts files. Dart lacks them, but there are tools to generate js bindings from those same .d.ts files.
https://github.com/jirkadanek/definitely_typed
I haven't used it though, so I can't say if it works as advertised.
> I'd say they replaced it with a better tool, pub.
Right but that route ends in forcing people to leap to a whole different ecosystem before they can even try your thing. Whereas with typescript you could put a single .ts file in your existing project without messing with anything else.
I consider the small hop to TS its greatest disadvantage, personally. JS's ecosystem is a horribly broken mess, and any sane person would welcome a leap to another, better designed one. Dart has JS-interoperability for those times when you just can't get away, but TS is like an anchor holding you down in the mire of the JS world.
What's awesome about `pub`? If you're talking to someone like me who uses `npm`, `webpack`, and is now considering `rollup` ... what am I missing if I don't look at `pub`?
It puzzles me also. Dart is solid language with great libraries, good tooling and still it is ignored by most developers. The truth is people from JS world seems to like 'cool' languages, but the one who want to be productive just uses boring Java/Dart etc.
I want to give Dart a chance, because most of it's features seem quite appealing. I decided to start learning JS/Jquery and then move onto to Dart. The fact that everything comes bundled into Dart as a whole dev environment (IDE, compiling,packaging,) and the interoperability with JS make it quite attractive.
What is your experience doing web dev with and without Dart (JS vs Dart, pros and cons)? I'd be really interested in your feedback!
I started off with C/C++, Java, then AS3 writing Flash games. Then js/jquery and I instantly hated it (js). There were just too many quirks, bizarre, unexpected behavior. Sure, I could learn it inside out and avoid these pitfalls, but why would I when there were better alternatives?
I did use CoffeeScript after that, a beautiful little language, but only suitable for smallish projects. I need static typing for large projects.
After that, I learned Dart, and coming from C/C++, Java, AS3, it was a breeze. I find there are no quirks, everything behaves as you'd expect. Other team members were productive in Dart in about a week, without having seen a line of Dart code.
I mostly write HTML5 games and server-side with Dart, so I can't really talk too much about any client-side frameworks.
As for Dart cons, I guess one would be you have to use a different browser for web dev, but it's not really a big deal, I'm kinda reaching here. There aren't as many 3rd party libraries as some other languages. Depending on what you want, you might have to get your hands dirty and issue some pull requests for features/bug fixes for those libs. JS interop can still be a bit tricky too, depending on what you're doing.
I'm going to try it on my Linux box. The only disadvantage I can see for my eventual needs after a second reading is the lack of 3D support. I can get by with 2D for most of my stuff, but for games, I need the 3D hook.
I'll have to see how easy it is to customize the Dart-provided widgets. Might be easier than creating them from scratch in OpenGL via the NDK.
TS is more of an evolution of what exists. In that sense it's a possible "future" implementation of JavaScript -- still keeping the same semantics, but in a more structured way.
Dart is a different language so it's a different path. It's no different than, say, using C# or Java or C or whatever language that can be transpiled to JavaScript.
I've been a long time fan of Dart but I've recently (this week) given up on it for my purposes, which are write browser SPA's that need to run in different browsers. My sense is that after the Chrome team decided not to include the Dart VM in Chrome, Dart started looking for a new story. That story is Flutter, which is Dart running in the Dart VM on mobile devices [1] It is not Dart converted to JavaScript so it can run in any browser, despite the awesome work of the dart2js authors and the relatively new dev_compiler project [2]. The latter will be awesome when done, because the goal is to convert Dart to ES6/ES2015. However, it is my impression that Google really doesn't care that much about transpiling Dart to JavaScript. I was willing to put up with the huge file size dart2js produced, because Dart made my life easier and something better was coming. However, it's been a long time and the pace of Dart transpiling work is too slow. I converted my Dart app to TypeScript (size dropped from 650kb to 60 kb) and am happy for that, but sad that Google does not put more people on the dev_compiler team to keep long term enthusiasts like me on board. I'm sure Flutter is fantastic and will take a look when I have a need for that kind of solution. I can't really blame Google, because the JavaScript community turned it's back on Dart, but I wish they would just state the new goals and not leave us hanging.
Dart is not structurally typed and so only provides help typing the parts of your program you have actually modified to use Dart. TS and Flow both provide structural typing that makes it far easier to convert existing code. Just annotate it (no need to even modify the existing code, just plop a `.d.ts` or `.flow` file in the right place) and immediately start to see benefits.
Sorry for my ignorance, but does that amount to loading a library on demand? If so, yes, Dart can do this:
import 'package:deferred/hello.dart' deferred as hello;
// When you need the library, invoke loadLibrary() using the library’s identifier.
greet() async {
await hello.loadLibrary();
hello.printGreeting();
}
