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by CyberDildonics 1011 days ago
In Haskell you can provide your own prelude, which uses unsafe functions without bounds checks by default.

So your solution is to rewrite the haskell standard library yourself?

With CPP or cabal tricks

I don't know what cabal tricks is supposed to mean here.
2 comments
one-punch 1010 days ago
(Can't resist this one line rebuttal)

> So your solution is to rewrite the haskell standard library yourself?

No need--the simplest solution is to pass flags correctly to the dependent library (set all flags BoundsChecks, UnsafeChecks, and InternalChecks to false for the vector package) for release builds.

Explanation after the one-line rebuttal:

This exactly matches the C++ behavior: no bound checks for release builds, but with bounds checks for debug builds. This shows that Haskell can do what C++ can do, very easily, just by passing compiler/cabal/stack flags correctly.

With this rebuttal, I think the issue is completely settled, at least for reasonable readers.

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CyberDildonics 1010 days ago
No need--the simplest solution is to pass flags correctly to the dependent library (set all flags BoundsChecks, UnsafeChecks, and InternalChecks to false for the vector package) for release builds.

If performance is an issue, why not just do this instead of dealing with "Liquid Types".

And with this rebuttal, the issue is now settled for all readers and even those differently abled that are using voice readers.

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one-punch 1009 days ago
Safety.

For pointer checks.

https://news.ycombinator.com/item?id=37440896

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CyberDildonics 1009 days ago
But why have a separate type system instead of just building it into the language. C++ could build in pointer checks and it would be in the same type system.

And with this rebuttal, the issue is now double settled.

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one-punch 1006 days ago
> But why have a separate type system instead of just building it into the language.

Excellent question. The existing "mainstream" languages (C++, Rust, Julia, or even Haskell) are not designed to support such applications as bound checks or pointer checks in their type systems, where certain runtime values/checks can affect/refine the types (as in dependent types, or refinement types which Liquid Types are based on).

It could be done (in some newer languages: Idris, Agda, Lean), but people have not figured out an ergonomic way to do so in more "mainstream" languages (e.g., not hurting type inference, light and maintainable proof burdens). Liquid Haskell is an attempt to bring refinement type to Haskell, as an extrinsic type system.

> C++ could build in pointer checks and it would be in the same type system.

People have not figured out how to do so (and I doubt if it is possible at all). Suffice to say:

* Rust is an attempt to build in lifetime-and-ownership-checks into the type system of C++, and Rust is a new language,

* Liquid Rust is an attempt to add pointer checks (refinement types) to Rust, and even then it is not built into Rust.

> And with _this_ rebuttal, the issue is now double settled.

People are still researching solutions (see Rust and Liquid Rust over C++) to this problem (building in pointer checks in the type system of C++), and they would love it if you can settle their problems.

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tome 1011 days ago
> With CPP or cabal tricks

> I don't know what cabal tricks is supposed to mean here.

It means conditional compilation, i.e. what the C preprocessor also gives you (but somewhat more principled).

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