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Comment by papa0101 | Hacker News Reader

That was google's original plan with Dart.

I believe Dart was originally gradually typed, and then abandoned the gradual typing for strict-typing-by-default? That doesn't quite sound properly type-safe to me although still safer than how Javascript is by default.

My only reference is a memory of this talk by Richard Feldman but I might be wrong or misremembering. https://www.youtube.com/watch?v=Tml94je2edk

Released 22 February 2018

Dart 2.0 implemented a new sound type system

Dart's type system, like the type systems in Java and C#, is sound.

https://dart.dev/language/type-system

Thanks for the link. I'm aware Dart currently has static typing similar to Java and C#, and has had it for some time,

My question was different though and I was asking (quoting comments further up the chain) whether "google's original plan with Dart" really was to allow for a programming language "which can be properly type-safe from the beginning".

It seems that claim about the original intent is false. I checked Wikipedia [0] which states "Dart 2.0 was released in August 2018 with language changes including a type system" and the reference they link seems to corroborate that, before 2.0, Dart didn't have a sound type system.

Thanks for prompting me to dig deeper (I probably wouldn't have done it without seeing your comment).

[0] Quote found under the history section. https://en.m.wikipedia.org/wiki/Dart_(programming_language)

Thanks, I was probably responding to “That doesn't quite sound properly type-safe to me” in isolation.

Is Dart sound these days? When I tried it, it was pretty easy to trigger type errors at runtime.

These days Dart — considers all variables non-nullable — enforces sound null safety."

https://dart.dev/null-safety

Well, null safety is a good start.

But I seem to remember that the type-checker got confused rather easily with nested closures, for instance, or co/contra-variance.

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