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.
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).
Care to elaborate on that?
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.
Official answer from https://www.dartlang.org/faq:
"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."
I'm not the OP, but TypeScript supports union types (A | B ; a type that can be either type A or type B) and intersection types (A & B ; a type that is both A and B), while Dart doesn't. https://www.typescriptlang.org/docs/handbook/advanced-types....
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.
Elaborate then. Because one's major advantages can be another's (and sometimes, objective) trivialities...
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.
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.