Compiler Reminders

#1

Post by jfmengels1 » Sun, Apr 27, 2025, 7:40 AM UTC

Re: Compiler Reminders

#2

Post by JonChesterfield » Sun, Apr 27, 2025, 12:43 PM UTC

Exhaustive compile time checking of dispatch statements is a wonderful thing, sorely missing from the languages that decided "sum types" are a bit weird and niche.

Re: Compiler Reminders

#3

Post by swiftcoder » Sun, Apr 27, 2025, 1:16 PM UTC

Elm Rust

Best buds on this front

Re: Compiler Reminders

#4

Post by gitroom » Sun, Apr 27, 2025, 2:35 PM UTC

Tbh, missing those checks in other languages bugs me so much - it's like why leave me hanging?

Re: Compiler Reminders

#5

Post by fredrikholm » Sun, Apr 27, 2025, 6:15 PM UTC

JonChesterfield wrote: post #2

Exhaustive compile time checking of dispatch statements is a wonderful thing, sorely missing from the languages that decided "sum types" are a bit weird and niche.

They make it near impossible to extend from the outside.

I can pass a Reader interface to your function, but I cannot (easily) add a

> | UnusualProtocol(Socket)

as a third party consumer.

Other than that, sum types are the better abstraction. With exhaustive first class pattern matching (eg. with proper matching on destructuring), nothing comes close in terms of ergonomics.

Re: Compiler Reminders

#6

Post by hermanradtke » Mon, Apr 28, 2025, 2:13 AM UTC

fredrikholm wrote: post #5

JonChesterfield wrote: post #2

Exhaustive compile time checking of dispatch statements is a wonderful thing, sorely missing from the languages that decided "sum types" are a bit weird and niche.

They make it near impossible to extend from the outside. I can pass a Reader interface to your function, but I cannot (easily) add a > | UnusualProtocol(Socket) as a third party consumer. Other than that, sum types are the better abstraction. With exhaustive first class pattern matching (eg. with proper matching on destructuring), nothing comes close in terms of ergonomics.

That is a feature. Compose instead of extending.

Re: Compiler Reminders

#7

Post by Yoric » Mon, Apr 28, 2025, 7:33 AM UTC

fredrikholm wrote: post #5

JonChesterfield wrote: post #2

Exhaustive compile time checking of dispatch statements is a wonderful thing, sorely missing from the languages that decided "sum types" are a bit weird and niche.

They make it near impossible to extend from the outside. I can pass a Reader interface to your function, but I cannot (easily) add a > | UnusualProtocol(Socket) as a third party consumer. Other than that, sum types are the better abstraction. With exhaustive first class pattern matching (eg. with proper matching on destructuring), nothing comes close in terms of ergonomics.

OCaml has extensible sum types. They work very nicely for some ranges of problems.