Programming

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[–] olafurp@lemmy.world 5 points 1 year ago (1 child)

Gradually typed is a great description because it's neither fully static or dynamic. TS does allow you to circumvent the types too easily to be called statically typed.

const strings: string[] = ([1] as any[])

Is ok in TS land so the type of strings is not really static so to speak because you can assign whatever to it. Writing this in Dart would give

error - The argument type 'List<dynamic>' can't be assigned to the parameter type 'List<string>'. - argument_type_not_assignable

if I'm not mistaken.

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[–] hikaru755@lemmy.world 3 points 1 year ago (1 child)

I get your point, but that's not a great example. Kotlin is a statically typed language, and this compiles (and runs!) just fine:

val test: List<String> = listOf(1) as List<String>
println(test) // prints "[1]"

Even val test: String = 1 as String will compile, but at least gives you an exception at runtime, which the equivalent typescript wouldn't.

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[–] olafurp@lemmy.world 2 points 1 year ago (1 child)

That's crazy, I thought that would be an invalid cast or something.

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[–] hikaru755@lemmy.world 2 points 1 year ago

Unfortunately not. You do get a warning that it's an unchecked cast at least.

Granted, the issue here is generic type erasure, which was a tradeoff that was decided on for backwards compatibility when generics were first introduced to Java, so it's not like an actually desirable feature of the language. But the point is that this wouldn't be reason for anyone to not call Java and Kotlin not statically typed, their type system is just a bit weaker than others in certain aspects