[dart-misc] What's the status of NNBD (and Strong Mode)?

[Danny Tuppeny]

There are a bunch of cases on GitHub relating to non-null by default, but
they don't seem to have had any activity in over a year :(

Is any effort going into this? Not being able to opt-out of nulls is my
biggest gripe with basically every language ever. Typescript now has it
(along with a bunch of other great stuff, like union types and a type
checker that narrows a union type based on the code)..

Also; is Strong Mode now "done" or still experimental? I found this page
<https://github.com/dart-lang/dev_compiler/blob/master/STRONG_MODE.md> but
not much more; so it's hard to tell where it's at.

Thanks!

[Mark Nordine]

I, too would love to know if any work has been done on NNBD. I think it
would be a great language feature to have.

Post by Danny Tuppeny
There are a bunch of cases on GitHub relating to non-null by default, but
they don't seem to have had any activity in over a year :(
Is any effort going into this? Not being able to opt-out of nulls is my
biggest gripe with basically every language ever. Typescript now has it
(along with a bunch of other great stuff, like union types and a type
checker that narrows a union type based on the code)..
Also; is Strong Mode now "done" or still experimental? I found this page
<https://github.com/dart-lang/dev_compiler/blob/master/STRONG_MODE.md>
but not much more; so it's hard to tell where it's at.
Thanks!

['Bob Nystrom' via Dart Misc]

Post by Danny Tuppeny
There are a bunch of cases on GitHub relating to non-null by default, but
they don't seem to have had any activity in over a year :(

Heh, my initial proposal is from 2011:
http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-null-safety-in-dart/
:-/

Post by Danny Tuppeny
Is any effort going into this?

Right this second, no.

Post by Danny Tuppeny
Not being able to opt-out of nulls is my biggest gripe with basically
every language ever. Typescript now has it (along with a bunch of other
great stuff, like union types and a type checker that narrows a union type
based on the code)..

Yeah, there's a lot of really neat stuff in TypeScript. I wish we done a
bunch of it first.

Post by Danny Tuppeny
Also; is Strong Mode now "done" or still experimental?

This is a great question.

Over the past several months, many on the team have been focused on getting
strong mode and DDC production-ready and migrating as much existing code to
be strong mode clean as possible. I believe the majority of code inside
Google is now strong mode clean and is being analyzed with strong mode
enabled.

We've gotten a ton of feedback from users and it's almost all positive.
(Not exactly a surprise to the people who created strong mode in the first
place, but a very nice confirmation.) Given that, I wouldn't say it's an
*experiment* anymore. I think almost the entire team is convinced that
strong mode is where it's at.

At the same time, it's not *done*. We are still tweaking the type rules.
One of the things that's really difficult about adding a stricter type
system later is keeping existing corpuses happy and minimizing user pain.
So the first release of strong mode wasn't as strong as we might like. For
example, it still allows implicit downcasts, and implicit casts from
dynamic. As we get more and more code strong mode clean, we can gradually
tighten those type rules to something closer to a conventional static type
system.

The end goal is not to get to a language that statically guarantees no type
errors with *zero* runtime checks, because that isn't practical in an
object oriented language. (In Java, C#, etc. explicit casts can fail at
runtime.) But it would be good to get to a point where it's pretty clear to
a user *where* one of those errors might occur and give them confidence in
the type safety of their code outside of those regions.

We are making a lot of progress on this. Once the basic foundation of
strong mode is stable, there's a list of type system additions we want to
investigate. Non-nullable types is, I think, the first one we will
investigate.

Cheers!

– bob

[Danny Tuppeny]

Post by Danny Tuppeny
Is any effort going into this?
Right this second, no.

That is super-specific, how about this month? ;P


Yeah, there's a lot of really neat stuff in TypeScript. I wish we done a

Post by Danny Tuppeny
bunch of it first.

Better late than never. TS is open source and compiles to JavaScript; you
can probably just copy/paste theirs and tweak it; be done in an afternoon!

Post by Danny Tuppeny
(Strong mode... <Snip>)

We are making a lot of progress on this. Once the basic foundation of

Post by Danny Tuppeny
strong mode is stable, there's a list of type system additions we want to
investigate. Non-nullable types is, I think, the first one we will
investigate.

Thanks for all the info! Shame about NNBD but the strong mode stuff sounds
positive, especially if non-nulls might follow on.

I remembered there was another dealbreaker with Dart for me... no
deserialisation of JSON (!)... maybe I can live with the nulls if that
works better now - seems the new build/source_gen stuff might address this,
I'll have to have a play...

But really; all I want is a nice portable language that runs on Windows,
ChromeOS and Linux (x86 and ARM), runs in all browsers, can be used to
build native Android apps, has strong type guarantees, can deserialise JSON
and has no concept of nulls. Is that really so much to ask? :P

[Don Olmstead]

And a unicorn. Don't forget the unicorn.

Post by Danny Tuppeny
Is any effort going into this?

Post by 'Bob Nystrom' via Dart Misc
Right this second, no.

That is super-specific, how about this month? ;P
Yeah, there's a lot of really neat stuff in TypeScript. I wish we done a

Post by 'Bob Nystrom' via Dart Misc
bunch of it first.

Better late than never. TS is open source and compiles to JavaScript; you
can probably just copy/paste theirs and tweak it; be done in an afternoon!

Post by 'Bob Nystrom' via Dart Misc
(Strong mode... <Snip>)

We are making a lot of progress on this. Once the basic foundation of

Post by 'Bob Nystrom' via Dart Misc
strong mode is stable, there's a list of type system additions we want to
investigate. Non-nullable types is, I think, the first one we will
investigate.

Thanks for all the info! Shame about NNBD but the strong mode stuff
sounds positive, especially if non-nulls might follow on.
I remembered there was another dealbreaker with Dart for me... no
deserialisation of JSON (!)... maybe I can live with the nulls if that
works better now - seems the new build/source_gen stuff might address this,
I'll have to have a play...
But really; all I want is a nice portable language that runs on Windows,
ChromeOS and Linux (x86 and ARM), runs in all browsers, can be used to
build native Android apps, has strong type guarantees, can deserialise JSON
and has no concept of nulls. Is that really so much to ask? :P
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['Bob Nystrom' via Dart Misc]

Post by Don Olmstead
And a unicorn. Don't forget the unicorn.

Unicorns are on the roadmap, though they are currently blocked on ponies
and magic. Once we have the latter two, unicorns should be a
straightforward addition.

– bob

[Don Olmstead]

Replace unicorns with Union Types and magic with NNBD and thats a nice
roadmap. Ponies already exist.

On Thu, Jul 28, 2016 at 1:06 PM, 'Bob Nystrom' via Dart Misc <

Post by 'Bob Nystrom' via Dart Misc

Post by Don Olmstead
And a unicorn. Don't forget the unicorn.

Unicorns are on the roadmap, though they are currently blocked on ponies
and magic. Once we have the latter two, unicorns should be a
straightforward addition.
– bob
--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
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[kc]

Post by Danny Tuppeny

Post by Danny Tuppeny
But really; all I want is a nice portable language that runs on Windows,

ChromeOS and Linux (x86 and ARM), runs in all browsers, can be used to
build native Android apps, has strong type guarantees, can deserialise JSON
and has no concept of nulls. Is that really so much to ask? :P

Why not? This is exactly what Google needs. A modern language that comes
between Java/C# and JS which is fast, secure and expressive, and runs on
the major modern hardware and software platforms (either directly or via
transpilation).

Dart 1.x didn't come off because it wasn't ambitious enough (mobile!) and
Google didn't seem to have it's weight behind it.

K.