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My blame of Crystal is still lacking of discriminated union (like in Rust) and the hard to use macros system (while powerful)

Other than that, it's powerful.

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There are union types, which despite being untagged might be enough in a lot of situations, and I believe has language support in things like switch statements.

https://crystal-lang.org/reference/latest/syntax_and_semanti...

Crystal union types are tagged as the actual type a variable contains is tracked.

I honestly have no idea how anything could work if they were not tagged. Like how on earth would you know what method to invoke?

You should look into the union keyword in C :)

(Basically the programmer has to figure out how discrimination works - you’re kinda on your own).

But eh, that is not the case in crystal. You are not on your own - the language knows what a variable is during runtime and you have plenty of ways to dispatch between the types.

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