cakeml VS F#

If I understand what you are asking about correctly, then I do think you are mistaken.

As a sibling comment observed, you would be proving something about a program, but proving things about programs is both possible and done.

This ranges from things like CakeML (https://cakeml.org/) and CompCert (compilers with verified correctness proofs of their optimizations) to something simple like absence of runtime type errors in statically strongly soundly-typed languages.

Of note is that you are proving properties of your program, not proving them perfect in every way. The properties of your program that you prove can vary wildly in both difficulty and usefulness. A sufficiently advanced formally verified compiler like CakeML can transfer a high-level proof about your source code to a corresponding proof about the behavior of the generated machine-executable code.

> A single IR with multiple passes is a good way to build a compiler

https://mlir.llvm.org/, which is using, is largely claiming the opposite. Most passes more naturally are not "a -> a", but "a -> b". data structures and data structures work hand in hand, it is very nice to produce "evidence" for what is done in the output data structure.

This is why https://cakeml.org/, which "can't cheat" with partial functions, has so many IRs!

Using just a single IR was historically done for cost-control, the idea being that having many IRs was a disaster in repetitive boilerplate. MLIR seeks to solve that exact problem!

You may want to look at [CakeML](https://cakeml.org) done in HOL4, there is also a nice proof pearl about a more .. minimalistic verified bootstrapped compiler also in HOL4.

CakeML

There is also Cake ML which is a formally verified functional programming language compiler and runtime.

There is also a CakeML -> Standard ML compiler though it seems to have been built to translate benchmarks and sort of old so I'm not sure how comprehensive it is: https://github.com/CakeML/cakeml/tree/master/unverified/front-end

> One guess is that lisps cope with being minimal through use of macros and metaprogramming, it's difficult for a typed language to support that level of metaprogramming while maintaining the various guarantees that one wants from such a system.

Difficult, but certainly not impossible [0].

[0] https://cakeml.org/

If this interests you, I'd highly recommend checking out CompCert (docs here) and CakeML.

F# F*

This year I've been attempting Advent of Code in my favourite programming language, F#. This is a beginner(ish) centered post about making incremental changes from the smallest possible solution to something more robust.

I can recommend polyglot notebooks in vs code, so you can mix different languages.Take a look athttps://fsharp.org/ for some project ideas and frameworks.

I have many less followers on Mastodon than in the Birdsite (40 vs 341), yet my activity has generated many more interactions than there. Not only that, among the users who decided to interact with me I counted: a co-discoverer of the Laniakea supercluster, one of the lead developers behind F#, the author of many important books on Java & JVM, plus many others. I'm literally a nobody, but this time there was no algorithm relying on relevance and engament metrics to decide what to present to each one of us.

FP devs differ based on language here. Elm, like F#, tends to encourage "a bunch of functions and types in a file". While Elm supports modules, we don't really care where it came from; they're all pure, all deterministic, the compiler tells us if it works.

The builtin fsharp collections actually are just "immutable", not persistent as you mention. (Ref: https://github.com/fsharp/fsharp/blob/master/src/fsharp/FSharp.Core/map.fs. This is just an AVL tree that returns a copy on mutations: https://github.com/fsharp/fsharp/blob/577d06b9ec7192a6adafefd09ade0ed10b13897d/src/fsharp/FSharp.Core/map.fs#L118)

You can dive into .NET ecosystem by trying F#. It's functional-first language so this should be familiar.

ReScript code is just like F# or OCAML; it doesn’t have a function parse phase like JavaScript, so we have to define our functions and types first before we can use them. That’s fine, but makes explaining the code backwards (meaning you start at the bottom of the file and work your way up), so we’ll start at our lambda handler and explain each part, regardless of where it’s defined.

F# is a JavaScript and .NET language for web, cloud, data-science, apps and more.

Also a programming joke