Ask HN: JS++ ? Why not make a new, strongly typed JavaScript ?
Javascript has a nice syntax but needs to be faster and more reliable.
With strong typing JS++ would eliminate many runtime bugs. Without all the crazy implicit conversions, boxing, 'eval', etc... fantastic speeds could be achieved.
Lots of electricity and developper hair could be saved.
JS++ would break backward compatibility but this could be softened by retaining the old syntax as largely as possible. With implicit and explicit typing.
It should be easy/automated to convert js to js++.
Inb4 ActionScript 3 : yes, something like that.
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[ 3.8 ms ] story [ 89.7 ms ] threadIf you've ever written typescript, you can see how a strongly typed JS gives you the worst of both worlds.
Typescript adds static typing to JS, but it’s still weakly typed. This post is about strong typing in JS, which I’m still scratching my head about.
I'm no type theorist and - per wikipedia - 'strong' is not precisely defined.
'Static' may be closer to my idea : a JS where `typeof` and Number.isInteger are of no use.
const o = {}; o.prop = "something"; // oh, actually, o.prop = 5;
and being able to do if( typeof o.prop === 'number' ) ...
I don't particularly care for the attitude that because something can be used to write horribly unmaintainable messes, it must necessarily be bad and have few practical applications.
No, if you get horrid unmaintainable messes it's because you're either inexperienced or a bad programmer, you may be able to hide that in layers and layers of corporate Java that adheres to every guideline, but the second anyone tries to touch it, you'll be found out anyway. I'm going to take a wild guess that you're also imbued with a similarly low opinion of PHP based on that (insightful if somewhat one-sided and flawed) article that guy wrote.
In my opinion, the flexibility and elegance you can get out of exploiting, not abusing or misusing, the dynamic nature of JS, is the main appeal of the language, it's really damn fast to get stuff done, and even done in a nice and safe way, provided you have some idea what you're doing.
There are terrible things that you can do in JS, and those are terrible even in the context of JS, but, what is a terrible thing to do in one language may be just fine(tm) in another, so trying to force some Java or C++ ideas onto any other language is just not a good way of going about things. Every language must be considered on its own.
What is reasonable to do when writing machine code may not be reasonable in assembler, and what is reasonable in assembler may not be reasonable in C and up you go.
Care to share some examples / use cases where using these language characteristics can result in better, more expressive, more readable code?
(Not saying there aren't. I've been wondering about it myself and am genuinely curious)
Thanks!
Nope they use const to define immutable references, the same way that val/var define mutable references.
If you don't understand the difference between mutability of a reference and mutability of the value it refers to, JavaScript is far from the only language you’ll have a problem with.
No, you clearly don't.
> The problem is that you can completely change the shape of the object that’s “const”
“const” is not a feature of objects, but of the reference to a value (which may or may not be an object).
You can't change the reference at all (unlike a var/let references), hence it is constant.
Object immutability is orthogonal to reference immutability and is attained by Object.freeze().
In C for ex.
means the value pointed at can't change, but means you can't reaffect pClean and elegant are certainly debatable, but, yes, code that is explicit in its preconditions (whether through explicit runtime checks or explicit static declarations or other mechanism) is pretty clearly more expressive than code that relies on the developer “knowing implicitly” the same information.
The above comments point to (a) not using classes or declared properties at all, and regardless JavaScript has no support for automatic type checks on properties or function arguments.
Strong typing usually describes the combination of compile and runtime typing; Haskell code doesn't have types after compilation, so there is no runtime enforcement of typing, but no one calls it weakly-typed, because the static typing prevents any of the conditions which would display weak typing behavior fromm happening.
Not in the browser.. Nor in the app/server.
See what I mean ?
JS matters most client-side anyway.
dealing with http queries, strings, regexp, json... is a lot of (unsafe) work..
You can absolutely write server web apps in C (there are even web app frameworks in C), though I wouldn't want to, or...
> The one in Node/Go/Python where you will write your business logic then `http.listen()`.
You definitely can link and call C code from Node, Go, and Python; they'd be much less useful otherwise; it's not at all hard in Python, and I assume the same is true of Node and Go.
WebAssembly as a target is a thing, so, yes, C is available there.
> Nor in the app/server.
How is C not available on the backend?
Actually, no. I genuinely think Typescript is amazing and I would love if there was native support one day.
That makes JIT a complicated business, for you still have to accept any value. So two versions of the func would have to coexist ? One strong and one weak ? I'm no JS/JIT expert..
It is like I thought : holding different optimisation versions of the same code... that is overly complicated in my (naive) view.
Because I -and everyone- need a faster, less energy-wasting JS.
> Are type errors the most common source of errors in JS?
They happen. And could be caught at compile-time under a stronger type system.
JS is used client-side in many banking/crypto webapps. I know everything is validated on the server but still presentation is done by JS with its nutty casts/coercions...
There are a good number of programming languages. Why not something like Go? I heard Go compiles to JS, but never tried it. Why is JS even used for banking, and why would converting to a JS++ be easier than adopting something else?
It may be possible to keep duck typing for objects while introducing fast unambiguous primitives like int64_t ?
> Why not something like Go?
Because JS syntax is very nice - that's my premise. Moreover, client side has to be JS, no other choice yet.
Want to accept muck? Leave it as is. Want to accept something specific? Specify the class to accept, or even specify the shape if you want to go the duck typing route.
If you are going to break from JS semantics by using strong typing rather than JS’s mostly-very-weak typing, I don't see what the point is of making code deceptively look like JS.