REPL for Dart | Hacker News Reader

REPL for Dart

github.com

116 pointstosh66 comments

There is so much cool stuff at various stages of landing in the Dart pipeline at the moment. A few things that come to mind include:

1. Dart now supports the native Web platform APIs and offers a really compelling alternative to TypeScript now thanks to their their latest generation of JS interop. Example for how the code looks here: https://github.com/kevmoo/kevmoo.com/blob/main/web/main.dart

2. Compile to WASM now on the web also with future work to also align itself with the emerging WASI standards both as a compile target and the ability to embed WASI runtimes into Dart programs (technically already possible through their C interop)

3. Lots of great work on cross language interop with C, C++, Swift, Rust, Go, JavaScript, Objective C, Kotlin and Java here https://github.com/dart-lang/native

4. Upcoming Macros feature which gives fully static type safe automatic and fully debugable code generation.

5. Potentially looking at bringing Shared Memory Multithreading to the language https://github.com/dart-lang/language/blob/2662d252b7fa93175...

6. Also some early work on a bytecode compiler it seems but I’ve not seen any kind of announcement about it here https://github.com/dart-lang/sdk/tree/main/pkg/dart2bytecode

7. This REPL

It’s really a good time to be a part of the community. It’s a very bright looking future for it.

I wasn't aware of that bytecode compiler, even though I work with Flutter/Dart on a daily basis. How did you find out?

Nonetheless, that’s some low level stuff that I have little experience with haha.

I spend some time each week just browsing the various repos under the Dart account to see what’s going on in the ecosystem and that turned up recently but as I said there no kind of announcement so I would take them very literally when they say it’s an experiment.

Where is JS Interop used in the first example? (It's a bit hard to tell with the wildcard imports how much of that is actually coming from web.dart.)

Web.dart is basically designed to give you the equivalent of any of the browser based APIs you would find on MDN essentially unchanged so things like document.querySelectorAll and things like that would just work as though you were using JavaScript (and you technically are in the background) but without otherwise needing to ever leave Dart.

Well, sure, but web.dart is one of the original packages that came with Dart. That part isn't new.

That’s not actually correct I don’t know where you got that from. This is from this year and was built on top of a wider rewrite of their JS interop using new language features to make it essentially a zero cost abstraction.

Dart has had browser support and DOM APIs before but never had the same APIs you have in the web platform before.

I think I had it confused with dart:html, which looks almost the same. I don't see a big difference in the example code.

> It’s a very bright looking future for it.

Err... At Google? After laying off the core maintainers? Not bright at all.

That literally never happened.

https://www.reddit.com/r/FlutterDev/comments/1cduhra/more_la...

Yes, there were layoffs. But "core maintainers" is not a term they use, and kind of fuzzy since people come and go; some early team members left well before then. People didn't all leave (or get laid off) at the same time, and they never laid off the entire team as far as I know.

https://www.reddit.com/r/FlutterDev/comments/1cduhra/comment...

Sure, whatever.

The one major company backing a project lays off a number of the team working on the project.

That is not exactly the signal of a bright future.

It would be cool if you could apply even the most basic reading comprehension here where it says there was zero change in team size and stop spreading nonsense.

Ok.

Here’s the top comment from the Reddit post that was linked

> Hey folks! Kevin, product manager on Flutter and Dart here.

> The layoffs were decided AT LEAST a couple of layers above our team and affected a LOT of teams. (I think I can say that). Lots of good folks got bad news and lots of great projects lost people. Flutter and Dart were not affected any more or less that others. It was a tough day...tough week.

Can you comprehend that?

Did you see the comment below the post?

> Hey folks! Kevin, product manager on Flutter and Dart here.

> The layoffs were decided AT LEAST a couple of layers above our team [...]

> Flutter and Dart were not affected any more or less that others.

That's exactly the post that confirms the layoffs and that Google moved some clueless extras to fill the gap. Which means the core maintainers were laid off. If one think that removing the main team of a project won't affect its speed and quality, one is absolutely delusional.

JFC how many times do you need to be told that what you’re claiming didn’t happen. You’ve been caught multiple times just straight up making up entire story lines that exist only in your head rather than just admitting that you had some bad information.

It’s genuinely one of the weirdest things I’ve seen on here in some time.

You seem to have issues with anger management and frustration related to people disliking Google because of how they often kill products they use. Screaming "It didn't happen" don't change thevfact that a big part of the team was laid off. Adding "headcount" doesn't change that.

Also, if you can't talk without offending and going out of your mind, you can just respect this forum guidelines and say nothing.

> a big part of the team was laid off

This didn’t happen the Flutter / Dart team specifically. You are portraying this as an issue with Flutter only.

Dart's only reason it is still among us is Flutter, if Google ever gets fed up with Flutter, it will fizzle out.

Meanwhile other programming language ecosystems have plenty of domains that keep them relevant no matter what.

I’ve seen you specifically make this exact same argument in almost every single thread that’s ever about Dart of Flutter for I think at least two years now. It’s a really weird fixation you seem to have.

It’s never come true, you’re talking nonsense just like every other time people try to politely explain it to you.

And yet you felt attacked to waste time replying, interesting....

If there’s a point in here I can’t find it.

I don’t “feel attacked” more frustrated that you’re here yet again to make the same crappy points knowing full well you have zero interest in having a real conversation or changing your mind.

It’s more akin to dealing with the drunk uncle at Christmas who tries to trap you into the same argumentative conversations that he did the past 3 years.

IMHO, some people just really want Dart and Flutter to fail, so they post the same tired doom prophecy in hope it will become self-fulfilling.

What is also annoying is that they come to normal Dart/Flutter related threads just to spoil them.

Meanwhile, the ecosystem grows, more and more people and companies choose Dart and Flutter and have fun creating software with this excellent toolchain.

The dogs bark, but the caravan goes on, as they say.

He posts a boilerplate comment slightly rephrased hundreds of times for several subjects, not just Dart. e.g. see any time Proton games on Linux comes up.

I hear this a lot. I don't really see Google getting fed up with flutter, due to what they have invested in it, but for the sake of argument let's say that did happen. Google abandons flutter. What happens next? Will it fizzle out?

To take your point about the domains, flutter's, and by association dart's, domain is cross platform development from one codebase. As far as I can tell nothing else comes close just now, that domain makes flutter relevant no matter what. Surely as opensources projects, both survive?

Open source only helps so much, depending on how many skilled developers are willing to take it forward.

How many programming languages and frameworks are out there as open source, that in reality are only limping along?

True enough, but I think flutter/dart have enough traction beyond Google that they'd survive. I like dart as a general purpose language too.

Even though I don’t use Dart myself I very much approve of this initiative.

I live in my Python REPL (ipython) and I couldn’t live without my hot reloading without losing state. Allows for hacking about a bit directly in the REPL. Once something starts to take shape you can push it into a file, import it into your REPL then hack about with it in a text editor.

The hot reloading is great when you have a load of state in classes and you can change code in the editor and have that immediately updated on your existing objects in the REPL.

After learning how to do this in lisp I've been missing it in python. Do you use anything alongside ipython to make this happen?

  from importlib import reload

Reload paired with inotify are the building blocks, to wire up yourself.

Config file here with a couple of lines to add it to ipython automatically.

https://github.com/aidos/dotfiles/blob/master/_config/ipytho...

Thanks!

jupyter-dart-kernel: https://github.com/vickumar1981/jupyter-dart-kernel :

  pip install jupyter-console jupyterlab -e https://github.com/vickumar1981/jupyter-dart-kernel#egg=jupyterdartkernel
  jupyter console --kernel jupyterdartkernel
  jupyter kernelspec --list

IPython/extensions/autoreload.py: https://github.com/ipython/ipython/blob/main/IPython/extensi... docs: https://ipython.readthedocs.io/en/stable/config/extensions/a...

Dart is really nice to write in, with far less mental overhead than some of its would-be competitors that couldn't possess the same wisdom and foresight at the time of their creation, so an interactive shell for it is pretty cool. In general I think it's slowly trying to carve its place in the world other than Flutter's language (for which many great packages have been made), but it doesn't have any other forefront project or library, and probably still carries a bit of prejudice from the Dartium mayhem and being a language looking for some purpose that could be orphaned by a blind-sighted Google at any time, the Ads story about it still comes up often. I'd like to see it around more.

I somewhat disagree.

Dart is a decent language for Flutter, but I’m not sure why you’d want to use it off of the flutter path. Maybe for CLI or other client-side tools? Either way, if you’re not re-using a dart package or using flutter, you absolutely should not pick it as your tool of choice.

The language seems nice syntactically, but I find it really frustrating in practice. It’s good enough for the “happy path” that was envisioned - basic UI hierarchies. It’s clear some team designed the language by first writing examples of what they wanted it to look like when making a UI. I think Swift UI caused similar complexities on Swift. You can confirm that even the contributors think this from reading controversial PRs in GitHub.

The nice thing about flutter, and Dart, is that it’s starting to take a life on outside Google. Google should hand off ownership to a foundation or other organization - especially now that their newest thing is Kotlin Multiplatform. I hear more and more companies writing flutter backends for their UI work, so hopefully it could survive alternative stewardship. I believe some TVs and car navigation systems now use flutter, plus all the google stuff.

Kotlin is a Jetbrains product, not a Google one.

I don't think the OP was making that point just that Google is now USING Kotlin.

Dart is my favourite language, it is the flutter framework I'm not so fond of. People literally designed better GUI frameworks than flutter 20 years ago. They did all sorts of weird things, probably for "performance" reasons, that forces the user to do things that kinda undo many of those "gains". Language wise, I love the fact that it comes with NULL safety out of the box, the number one feature I miss in GO-lang is NULL safety. NULL safety has very low cost to syntax or compile efficiency, and literally takes away half your program crash possibilities.

> People literally designed better GUI frameworks than flutter 20 years ago.

Which ones? Flutter is quite good, especially compared to things like Java Swing or GTK.

Delphi VCL, Windows Forms, WPF, Cocoa,

exactly. Borland era OOP gui code was amazingly well thought out. The flaws in the flutter framework are soooo many, a lot of half baked things are made standard. Try to get 2-way scrollbars working decently (try to nest them, or go watch the video tutorials that supposedly explain how to do this - it was an absolute horror show). There are so many hassle factor things that one googles or searches the github for, find tons of other smart people beg for it with examples and use cases and just watch the team say they won't implement for some or other reason. But even the simplest thing, that when you create a component (say with mutable state) - you don't create one class to get one widget defined, noooo you have to create two, one stateful and one stateless. All of these little weird decisions that were made for bs reasons eventually add up to a ton of incidental complexity. Oh we made part immutable for "performance" reason, but the real reason is that people don't understand when to avoid functional style programming idioms. All the weird ways the layout system can bite you, the way they designed constraints being passed down and sizes passed back up - boy are they forcing you to do a lot of thinking about incidental complexity, and the different containers and how thy interact in ways you would not expect by default. The fact that you cannot on a per container basis disable overflow displays in dev (many people have asked for this). That silly debug ribbon your app gets until you disable it LOL who thought that was a good default. In the end though one can make it do a lot, and it is reasonably performant. But the pitfalls are many, and basic stuff that it doesn't solve well for you.

Golang doesn't have an alternative ownership structure. Kotlin doesn't have an alternative ownership structure. Why is it important for dart and flutter? This feels like moving goal posts.

If there were major other entities seeking to participate in its development and advancement I could see a reason to change things, but that doesn't seem to be the case.

First, I was defending Dart/Flutters ownership structure - Google's support seems weak, but many other companies are taking a stronger interest in the ecosystem, so that's encouraging to it's long-term future. Meanwhile, Google seems to be turning to non-flutter tools in their approach to cross-platform development, so it is questionable how much support Google will give it long-term, as their needs change.

I think that Google should explicitly encourage and support the ecosystem by moving key tooling to a third party foundation, even if staffed by their employees - eg. the pub.dev package manager could be maintained independently and get a team dedicated to it. Google would be then free to drop support, or change direction, without dragging this great ecosystem down to stagnate.

Golang/Kotlin are seeing strong, and continued, support amongst their owners, and their support isn't questioned. That said, many people have questioned the direction of Golang because the only maintainers are Google employees, and they don't listen to much outside opinions for direction.

Not strictly related (because it doesn't have a working REPL yet) but may also find ClojureDart of interest.

https://github.com/Tensegritics/ClojureDart

This is the same author as the awesome flutter rust bridge: https://github.com/fzyzcjy/flutter_rust_bridge

Thanks for everything you've done for the dart community!

From the same author that did flutter_rust_bridge :) https://github.com/fzyzcjy/flutter_rust_bridge

Really nice work!

Isn't there any fix for this? https://github.com/fzyzcjy/dart_interactive?tab=readme-ov-fi...

dart's syntax is very easy to pick up, sadly it's defined as a 'client-side language', instead of a general purpose one, otherwise I would invest more time into it.

while flutter is cross platform I think for the web, WASM is its focus, which I dislike, not sure what JS interop mentioned in the comment here really does. can Dart be compiled to readable JS?

https://dart.dev/interop/js-interop

They dropped that “client side” framing a while back thankfully. It’s considered a general purpose language at this point.

One of the postgresql client packages (posgres) is roughly 8 years old. That's how "client side" it ever was...

Is there any way this can be used to evaluate code at runtime (e.g in a Flutter app)?

If you want to evaluate code at runtime, check out “flutter remote widgets”.

This is the “built in” way to do runtime evaluation. It lets you dynamically load things. Google used this in some LLM demo where an AI created a UI in response to a user query.

I love repl and I hope more languages implement it.

Reply on news.ycombinator.com