Clojure and clojurescript are both dynamically typed, but clojure is strongly typed (type errors throw exceptions), and clojurescript is weakly typed (type errors are technically valid code). Too many clojure enthusiasts act like they're both the same language, but that is an absolutely massive difference.
Try the following code out in each: (+ "1" 1). In clojure you get an exception, in clojurescript you get "11" (maybe a warning at compile time which won't show it's face at runtime when the data is fed to you from an API call).
That bug silently corrupted analytics data for 3 months for a service I worked on. That alone was the reason I stopped using dynamically typed languages.
> That alone was the reason I stopped using dynamically typed languages.
Nitpick, but weakly typed not dynamically typed is the problem here. Python would throw an exception (though I know mostly prefer JS with TypeScript to Python nowadays.)
Yes, in this particular instance that would be correct. But tracking down that bug made me realize something. A well tested program, fed improperly typed inputs, will fail in different places depending on it's type discipline.
With the weakly typed language, it will fail anywhere within your codebase and won't tell you that it is doing so.
With the strong/dynamic types, it will still fail anywhere, and while it will fail loudly, it still leaves you with the work of tracking down why. You won't know that it is due to improperly typed IO until you've traced that data flow all the way back from the point of the failure. For large apps, this can be a nightmare.
With a static/strong typing discipline, type errors can only occur in one place: exactly at the point where objects are constructed during IO.
And let's say that that upstream API provider (that you have no control over) silently switched to bignum strings instead of floats, your strong type system caught the problem immediately, and now you have to accommodate. You change the object, and get a stream of type errors in your IDE, and you go around fixing them all until they disappear. Almost like magic, your program works again. No new tests, no running multiple times until you track down all the type errors. With a dynamically typed language you'll have no such luck.
Frustratingly many statically typed languages are not very strongly typed since they don't force you to check for null values. Kotlin/Swift/Rust really are a huge improvement over Java/Go/C#.
At it's best TypeScript feels very similar to programming in one of these OCaml like languages, though you're still vulnerable to errors in untyped dependencies or people on your project abusing the `any` escape hatch.
(+ 1 “1”) is not a type error for CLJS, because it’s not a type error for JS. Clojure is designed as a hosted language and it shares all the basic types and operations with the host platform.
That's perfectly fine. In fact, it would probably have too much overhead to try to build a dynamic/strong runtime on top of javascript, so adopting the platform's type discipline was probably a wise choice.
However, the type discipline is a fundamental aspect of the definition of a programming language, and you can't exactly call it the same language if it has a completely different type discipline on different platforms. And it would be nice if clojure advocates stopped lying to people about how it is the same language. Be transparent about how different it really is, even if it looks the same on the surface.
Clojure and clojurescript are both dynamically typed, but clojure is strongly typed (type errors throw exceptions), and clojurescript is weakly typed (type errors are technically valid code). Too many clojure enthusiasts act like they're both the same language, but that is an absolutely massive difference.
Try the following code out in each: (+ "1" 1). In clojure you get an exception, in clojurescript you get "11" (maybe a warning at compile time which won't show it's face at runtime when the data is fed to you from an API call).
That bug silently corrupted analytics data for 3 months for a service I worked on. That alone was the reason I stopped using dynamically typed languages.