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by grumpyprole 2570 days ago
From a type-theoretic point of view, Python is unityped: https://existentialtype.wordpress.com/2011/03/19/dynamic-lan...

Python has a lot of merit as an easy to use language, a modern BASIC, but "strongly typed" is marketing that confuses rather than enlightens (to quote Prof. Harper). The term "strongly-tagged" is perhaps more apt, but sadly that ship has sailed.
1 comments
codr7 2570 days ago
So what you and Harper are saying is that Python only has one static type? While that is sort of true, I can't see how its leading anywhere. Many static languages have no dynamic types, I think that's worse.

Strongly typed used to mean safe, as in you can't add strings to ints or reinterpret values. As opposed to C and others where anything goes. I think that's a useful distinction.

Imagine all that lovely energy poured into understanding the compromises involved in designing realistic type systems. But its messy, and you don't become famous from dealing with messy problems.

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willtim 2570 days ago
> Many static languages have no dynamic types, I think that's worse.

I can't think of a static language that doesn't support a dynamic type, it's just that most require explicit casts or unpacking to use with existing typed interfaces, e.g. "Object" in Java.

> Strongly typed used to mean safe

It still does, it's just that type theory doesn't distinguish between a runtime failure with a nice error message versus a segfault, both are programs that "go wrong".

I would be in favour of "strong dynamic types" instead of "strongly typed".

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codr7 2569 days ago
I don't know enough Haskell or Rust to claim its impossible (outside of unsafe of course), but it clearly goes against the design of the language and is meant as fallback more than option.

Yes, you can write Java using nothing but Object. And no, the experience won't be comparable to using a dynamically typed language.

Map is not terrain, if theory doesn't match reality then changing the former is the only thing that makes sense.

Categories are generalizations, making them more specific weakens them. A RISC approach works better from my experience, where categories are kept trivial and members belong to multiple categories.

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