Hacker News with Generative AI: Type Systems

What would it take to add refinement types to Rust? (yoric.github.io)
A few years ago, on a whim, I wrote YAIOUOM. YAOIOUM was a static analyzer for Rust that checked that the code was using units of measures correctly, e.g. a distance in meters is not a distance in centimeters, dividing meters by seconds gave you a value in m / s (aka m * s^-1).

Rust, Programming Languages, Static Analysis, Type Systems

136 points by Yoric 26 days ago | 94 comments

What would it take to add refinement types to Rust? (yoric.github.io)
A few years ago, on a whim, I wrote YAIOUOM. YAOIOUM was a static analyzer for Rust that checked that the code was using units of measures correctly, e.g. a distance in meters is not a distance in centimeters, dividing meters by seconds gave you a value in m / s (aka m * s^-1).

Rust, Programming Languages, Static Analysis, Type Systems

26 points by leosarev 26 days ago | 3 comments

Nominal for Storing, Structural for Manipulating (bearblog.dev)
Something that comes up sometimes in programming languages is the difference between nominal and structural type systems.

Programming Languages, Type Systems

49 points by todsacerdoti 59 days ago | 32 comments

Adding row polymorphism to Damas-Hindley-Milner (bernsteinbear.com)
Damas-Hindley-Milner (HM) is a type system for Standard ML and the ML-family languages.

Programming Languages, Type Systems, Functional Programming

211 points by surprisetalk 87 days ago | 56 comments

Damas-Hindley-Milner inference two ways (bernsteinbear.com)
Damas-Hindley-Milner (HM) is a type system for the lambda calculus (later adapted for Standard ML and the ML-family languages) with parametric polymorphism, aka generic functions. It sits at a sweet spot in PL design: the type system is quite expressive, and there are well known type inference algorithms that require absolutely no annotations from the programmer.

Programming Languages, Type Systems, Lambda Calculus

139 points by todsacerdoti 94 days ago | 11 comments

A dictionary of single-letter variable names (jackkelly.name)
Haskell’s expressive type system means that type signatures can carry a lot of information. Haskell’s polymorphism means that you sometime write a function that works across an enormous range of types, and are often left wondering “what do I actually call my variables?”. It is often the case that there’s nothing to say beyond “this variable is a Functor”, or “this variable is a monadic action”, and so a single-letter variable name is appropriate.

Haskell, Programming Languages, Type Systems, Variable Names, Best Practices

110 points by todsacerdoti 98 days ago | 91 comments

Flux: Refinement Types for Rust (youtube.com)

Rust, Programming Languages, Type Systems

6 points by todsacerdoti 148 days ago | 0 comments

Higher-kinded bounded polymorphism in OCaml (2021) (okmij.org)

Programming Languages, Functional Programming, OCaml, Type Systems

141 points by tinyspacewizard 173 days ago | 10 comments

A type system for RCL, part 2: The type system (ruudvanasseldonk.com)

Programming, Type Systems, RCL

30 points by todsacerdoti 183 days ago | 8 comments

Counterexamples in Type Systems (counterexamples.org)