Stop overcalculating a mess out of junk, learn Rust and see what a Typesystem should and shouldn't have to do.
Show HN: Conway's Game of Life in TypeScript's type system
41–48 of 48 posts
Re: Show HN: Conway's Game of Life in TypeScript's type system
#42Sometimes I think I don't understand TypeScript's type system and then I see something like this and I realize I know even less than I thought
Typescript has conditional types, which means it can be used as a programming language itself. In theory you can write any arbitrary program - game of life is just an example. You have to define numbers and arithmetics from scratch though, so it is not very practical.
Conditional types are probably rarely used in practial code, but it opens the door for a lot of geekery.
Re: Show HN: Conway's Game of Life in TypeScript's type system
#43This is probably the slowest Game of Life ever.
Re: Show HN: Conway's Game of Life in TypeScript's type system
#44Sometimes I think I don't understand TypeScript's type system and then I see something like this and I realize I know even less than I thought
Typescript has conditional types, which means it can be used as a programming language itself. In theory you can write any arbitrary program - game of life is just an example. You have to define numbers and arithmetics from scratch though, so it is not very practical. Conditional types are probably rarely used in practial code, but it opens the door for a lot of geekery.
We’re using conditional types for type inference in garph (https://garph.dev)
Re: Show HN: Conway's Game of Life in TypeScript's type system
#45Love it! Reminds me of the hilarious "Typing the technical interview" [1] and "Typescripting the technical interview" [2], a couple of my favorite blog posts of all time. [0] https://aphyr.com/posts/342-typing-the-technical-interview [1] https://www.richard-towers.com/2023/03/11/typescripting-the-...
Don't forget "Rewriting the technical interview":
https://aphyr.com/posts/353-rewriting-the-technical-intervie...
Re: Show HN: Conway's Game of Life in TypeScript's type system
#46Earlier quoted context omitted.
this is exactly what I want from the Types as Comments proposal[0] as I think it's the only way that types can feasibly become part of the language. It's hard to imagine how all of the concepts TS introduces via special syntax can be covered otherwise. [0] https://tc39.es/proposal-type-annotations
I mean this seems like a nice proposal, but I guess I’m missing something, how does it relate to my comment?
That proposal aims to allow type annotations as part of JS, but to do that the parser needs to know when a type annotation starts (easy) and ends (hard), the only realistic ways that can be done at the moment is explicitly supporting all of the syntax TS introduces (which is bad for other type checkers) or restricting to a limited subset which would mean a lot of what TS supports would not be allowed, negating the usefulness of the proposal.
What I'm saying is that if instead we said that all type annotations must follow existing JS grammar rules, with perhaps a couple of small additions, then we'd be able to support all sorts of complex type annotations in JS directly, using existing syntax. This would mean that TS's grammar would end up changing a bit, but that's a small price to pay for ongoing interoperability.
For example, instead of
type UserProperties = keyof typeof User;
type UserProperties = keyOf(typeOf(User));Re: Show HN: Conway's Game of Life in TypeScript's type system
#47At this point, TypeScript should just let us define types using plain imperative TS code that will execute during static analysis. Might as well. type MyType = someFunc(T) Of course these functions might be typed too…
I recently had the insight- surely induced by reading something on HN or listening to some podcast- that types are simply functions from the set of all possible "values" to a logical value...
Yeah, a type is really just a set (in the mathematical sense). And a set can be defined by a function to {0, 1}. I don’t know if this function has a formal name, byt you can think of it as a “is this value a member of the set?” function.
Re: Show HN: Conway's Game of Life in TypeScript's type system
#48Earlier quoted context omitted.
commenting for future reference. that's a great quote.
Thanks. The Shen language takes this to its logical conclusion (pun intended) and implements a fully Turing complete type system. Types are specified with sequents which are essentially Prolog relations using a slightly different notation.[1] 1: https://shenlanguage.org/OSM/Recursive.html
Yes! I have played with Shen before.
IIRC the type checker is literally a Prolog.