Giraffe VS dafny

Giraffe is another interesting one to explore: https://giraffe.wiki/

Giraffe is nice because it is itself built "just" as ASP.NET Core Middleware so it plays a bit more nicely than Suave with a mixed stack of C#-defined Middleware.

It's more likely you accidentally fall back into just translating C# patterns to non-idiomatic F# with Giraffe, but it's also nicer when in that case of needing to live in both worlds and use a mixture of libraries built for C# ASP.NET projects.

There are also some F# frameworks built on top of ASP.NET core like https://giraffe.wiki

If you have an interest in F#, I highly recommend diving in because (1) it has a ton of things you might learn to appreciate in C#; (2) it has things C# cannot have. I do like some of the suggestions people have made regarding mixing your code bases, but I'll also say that building, say, endpoint routing in Giraffe is (to repeat myself) easy, simple, and elegant.

Bix is a micro-framework designed with F# in mind and that runs on both Deno and Bun! and in theory it also should even run in a service worker! (intercepting fetch requests) although I haven't tested that yet, it offers a general purpose handler that coupled with a set of route definitions it can bring a Giraffe/Saturn like framework to life in JavaScript runtimes which is incredibly awesome! useful? maybe not 😅, but awesome indeed. Let's see some code for it

Backend: Most likely it would be a toss between https://saturnframework.org or https://giraffe.wiki. They both combins the extremely good type system in F# combined with the ease of a minimal API.

I was wondering if its possible to simultaneously run a C# core MVC project in combination with https://github.com/giraffe-fsharp/Giraffe

By default Giraffe, the framework which I use as a web server, uses Newtonsoft.Json to serialize results to JSON. However, for discriminated union, it generates quite a lot of JSON so I've switched to System.Text.Json which is built into newer versions of .Net Core. In combination with FSharp.SystemTextJson package allows serializing discriminated unions more gracefully. All we need is to decorate Branch type with JsonFSharpConverter(JsonUnionEncoding.BareFieldlessTags) attribute.

Giraffe is a library that sits atop ASP.NET Core and allows developers to build web applications in a functional style; dotnet new giraffe is literally my starting point when I begin a new web application project. (Rather than write three more sentences filled with effusive praise, I’ll just leave it at that; it’s great.) It also provides a view engine (that builds upon Suave‘s “experimental” view engine) which uses an F# DSL to define HTML in a strongly-typed way. It has been incredibly efficient for a while, but with .NET’s work over the past two releases at improving performance, and Giraffe’s adoption of those techniques, it is lightning fast.

Wrapping ASP.NET Core to be easier and more idiomatic with F# seems to be a common domain. Out of curiosity, did you look at any existing projects? If so, what was lacking from them that made you decide to write WebFrame?

Giraffe: https://github.com/giraffe-fsharp/Giraffe

Code correctness is a lost art. I requirement to think in abstractions is what scares a lot of devs to avoid it. The higher abstraction language (formal specs) focus on a dedicated language to describe code, whereas lower abstractions (code contracts) basically replace validation logic with a better model.

C# once had Code Contracts[1]; a simple yet powerful way to make formal specifications. The contracts was checked at compile time using the Z3 SMT solver[2]. It was unfortunately deprecated after a few years[3] and once removed from the .NET Runtime it was declared dead.

The closest thing C# now have is probably Dafny[4] while the C# dev guys still try to figure out how to implement it directly in the language[5].

[1] https://www.microsoft.com/en-us/research/project/code-contra...

[2] https://github.com/Z3Prover/z3

[3] https://github.com/microsoft/CodeContracts

[4] https://github.com/dafny-lang/dafny

[5] https://github.com/dotnet/csharplang/issues/105

I don't think something that specific exists. There are a very large number of formal methods tools, each with different specialties / domains.

For verification with proof assistants, [Software Foundations](https://softwarefoundations.cis.upenn.edu/) and [Concrete Semantics](http://concrete-semantics.org/) are both solid.

For verification via model checking, you can check out [Learn TLA+](https://learntla.com/), and the more theoretical [Specifying Systems](https://lamport.azurewebsites.net/tla/book-02-08-08.pdf).

For more theory, check out [Formal Reasoning About Programs](http://adam.chlipala.net/frap/).

And for general projects look at [F*](https://www.fstar-lang.org/) and [Dafny](https://dafny.org/).

Dafny and Whiley are two examples with explicit verification support. Idris and other dependently typed languages should all be rich enough to express the required predicate but might not necessarily be able to accept a reasonable implementation as proof. Isabelle, Lean, Coq, and other theorem provers definitely can express the capability but aren't going to churn out much in the way of executable programs; they're more useful to guide an implementation in a more practical functional language but then the proof is separated from the implementation, and you could also use tools like TLA+.

https://dafny.org/

https://whiley.org/

https://www.idris-lang.org/

https://isabelle.in.tum.de/

https://leanprover.github.io/

https://coq.inria.fr/

http://lamport.azurewebsites.net/tla/tla.html

> I think we can assume it won't be as efficient has hand written code

Actually, surprisingly, not necessarily the case!

If you'll refer to the discussion in https://github.com/dafny-lang/dafny/issues/601 and in https://github.com/dafny-lang/dafny/issues/547, Dafny can statically prove that certain compiler branches are not possible and will never be taken (such as out-of-bounds on index access, logical assumptions about whether a value is greater than or less than some other value, etc). This lets you code in the assumptions (__assume in C++ or unreachable_unchecked() under rust) that will allow the compiler to optimize the codegen using this information.

Most of the proof assistants out there: Lean, Coq, Dafny, Isabelle, F*, Idris 2, and Agda. And the main concepts are dependent types, Homotopy Type Theory AKA HoTT, and Category Theory. Warning: HoTT and Category Theory are really dense, you're going to really need to research them.