csharplang
dafny
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csharplang | dafny | |
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262 | 31 | |
10,868 | 2,665 | |
1.3% | 1.5% | |
9.6 | 9.7 | |
3 days ago | 3 days ago | |
C# | C# | |
- | GNU General Public License v3.0 or later |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
csharplang
- Discriminated Unions: Essa feature faz falta no CSharp
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DevDocs
Certain parts of Microsoft Learn are permissive, for example the .NET BCL documentation is Creative Commons Attribution: https://github.com/dotnet/dotnet-api-docs as is ASP.NET Core: https://github.com/dotnet/AspNetCore.Docs (a good hint if documentation is permissively licensed and on GitHub is if there's an edit button at the top.)
The C# language specification is unfortunately a bit fuzzier: https://github.com/dotnet/csharplang/discussions/4855
The updated unified C# language specification is CC, but it's still catching up to modern C#: https://github.com/dotnet/csharpstandard
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The golden age of Kotlin and its uncertain future
No OP, but for example you still see the C# folks still struggling to add discriminated unions to the language because of complex interactions due to its too many features[1]. Virtual threads are easier to use than async/await is another example.
[1] https://github.com/dotnet/csharplang/issues/113
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When static types make your code shorter
For example, C# had a research fork called Spec# that had compile-time support for contracts, with keywords such as requires (for arguments) and ensures (for return values), all the way back in 2004. While still being discussed, it doesn't seem to be shipping any time soon.
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.NET 8 – .NET Blog
Hi there. I'm the language designer who created the 'Collection Expression' design/specification: https://github.com/dotnet/csharplang/issues/5354
You can see the entire history of the proposal there. To answer you specific question, we went with `..` because that's what the language already uses for the complimentary 'pattern matching deconstruction' form for collection patterns.
In other words, you can already say this today:
if (x is [var start, .. var middle, .. var end]) { ... }
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What's new in C# 12: overview
You must specify concrete type.
There was a plan to have "natural type" so "var list = [1,2,3]" would be of type "List" but it was postponed to C# 13 (https://github.com/dotnet/csharplang/issues/5354#issuecommen...)
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Robust Design through Value Objects in C#
While C# currently lacks direct support for this kind of functionality, there's a glimmer of hope with an active proposal under discussion that aims to bring this feature to the language. This potential addition promises a future where C# can natively offer similar robust type narrowing.
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The combined power of F# and C#
Given few people anticipated ValueTuple and C# adding a more direct tuple syntax, I feel like it is only a matter of time before C# adds discriminated unions.
(There are multiple proposals tracking the idea. This seems the most comprehensive and "central": https://github.com/dotnet/csharplang/issues/7016)
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Should i quit Django and move to asp.net
I always liked list abbreviations in python, but I absolutely love Linq. I believe there is a feature proposal for C# 12, which makes collection initialization better imo.
- Can constructor parameter assignment be made less verbose?
dafny
- Dafny is a verification-aware programming language
- Candy – a minimalistic functional programming language
- Dafny – a verification-aware programming language
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Lean4 helped Terence Tao discover a small bug in his recent paper
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
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The Deep Link Equating Math Proofs and Computer Programs
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
- The Dafny Programming and Verification Language
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In Which I Claim Rich Hickey Is Wrong
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
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Programming Languages Going Above and Beyond
> 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.
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What are the current hot topics in type theory and static analysis?
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.
What are some alternatives?
language-ext - C# functional language extensions - a base class library for functional programming
tlaplus - TLC is a model checker for specifications written in TLA+. The TLA+Toolbox is an IDE for TLA+.
jOOQ - jOOQ is the best way to write SQL in Java
FStar - A Proof-oriented Programming Language
SharpLab - .NET language playground
rust - Rust for the xtensa architecture. Built in targets for the ESP32 and ESP8266
SQLDelight - SQLDelight - Generates typesafe Kotlin APIs from SQL
koka - Koka language compiler and interpreter
runtimelab - This repo is for experimentation and exploring new ideas that may or may not make it into the main dotnet/runtime repo.
Rust-for-Linux - Adding support for the Rust language to the Linux kernel.
.NET Runtime - .NET is a cross-platform runtime for cloud, mobile, desktop, and IoT apps.
interactive - .NET Interactive combines the power of .NET with many other languages to create notebooks, REPLs, and embedded coding experiences. Share code, explore data, write, and learn across your apps in ways you couldn't before.