G# – A modern .NET language with Go, Kotlin, and Swift ergonomics

https://davidobando.github.io/gsharp/

by serial_dev • 11 days ago

118 104 11 days ago

davidobando.github.io

Looks nice, congratulations.

I feel like we've done full circle. Languages are back to being (mostly) procedural. I'm not sure I like it, but it seems that this is what people prefer.

Personally, I'd rather see something like dependant types on a dotnet language. An addition, not just a simplification.

demosthanos• 7 days ago

I feel like we've done full circle. Languages are back to being (mostly) procedural. I'm not sure I like it, but it seems that this is what people prefer.

Is this an actual shift, or is this just what happens when LLMs make it possible for anyone to build a language quickly?

This one feels less like someone thought carefully about what semantics they wanted to have and more like someone without a lot of familiarity with the design space of programming languages decided to build one that had all their favorite features from the languages that they already know:

G# brings Go-, Kotlin-, and Swift-style ergonomics — packages, func, data class, nullable handling with if let, structured concurrency with scope — to the .NET runtime.

Nothing wrong with that at all, I love to see the increased interest in language design, but I wouldn't read a shift in preferences into this wave of PLs. It's a shift in who is writing PLs, not a shift in preferences.

chews• 7 days ago

dupe: https://news.ycombinator.com/item?id=48876506

gnabgib2• 7 days ago

You've been tricked by the SCP, this is the dupe - check the IDs (it's older than the one you linked to.. although there's also the one 31 days ago /w 9 points/2 comments from the OP)

onlyrealcuzzo• 7 days ago

Just trying to offer some help here, not an attack:

``` G# brings Go-, Kotlin-, and Swift-style ergonomics — packages, func, data class, nullable handling with if let, structured concurrency with scope — to the .NET runtime. Source compiles directly to managed assemblies. ```

This is a decent description - but as someone also building a language in a similar space - who isn't super familiar with the .NET runtime... My first question is... Why not C#?

I'm by no means a C# expert, but I thought most of this was supposed to be in C#. C# is not terribly un-ergonomic, and Go is simple, but not really ergonomic except for Goroutines...

`packages` and `func` being the first two selling points is alarming. Sure, people probably prefer `fn foo() -> Dog` over `Dog foo()`. No one's picking a language for that. C# has namespaces... C# has `record` and `record struct`. C# has not-ideal nil handling, but it still has it. I'm not convinced `if let` is better enough to be a selling point - a lot of people don't like that!

Your main selling point seems like `scope` and your concurrency model vs C#, but C#'s is not exactly terrible...

Rich Hickey has a joke about semi-colons in language design, and your main pitch seems to sell yourself short.

Btw, I think your GitHub page does your language a lot better justice.

Syzygies• 7 days ago

Rich Hickey has a joke about semi-colons in language design

I didn't see semicolons, but I saw plenty of {} braces, and I can't explain why they're needed.

https://github.com/Syzygies/Compare

"I'm already quite sure how I will die: I'll read another article on Hacker News about a new programming language where I see nothing new, and I'll read that they included {}; to make C programmers comfortable. I'll have a massive stroke."

AdieuToLogic2• 7 days ago

I didn't see semicolons, but I saw plenty of {} braces, and I can't explain why they're needed.

"Curly braces" (a.k.a. "{}") make lexicographical scope simpler to manage for lexers and parsers. Alternate grammars increase compiler complexity, excluding trivial token replacement.

As for semicolons, they are only a linguistic requirement for supporting multiple executable statements on the same source-code line.

narnarpapadaddy• 7 days ago

It’s probably too little too late in the age of Claude…

C# grew all those features over time. It had to leave syntax to support old patterns to preserve backwards compatibility. Thus, the syntax has grown a bit noisy over time to support all those features. This is reboot keeping the newer ergonomics and streamlining the syntax.

I probably wouldn’t adopt it for existing projects or use .Net for any future project, but it looks really nice for what it is.

Kuyawa• 7 days ago

I like it. I consider myself picky with regards to weird syntax in new languages and this is terse and very readable. Approved!

achr2• 7 days ago

What is it bringing from those languages? The FAQ reads like it is just altered syntax for C#, no difference in semantics or function.

gwbas1c• 7 days ago

How is this different than C#? What new concepts does this bring that C# doesn't?

20 years ago there was some momentum behind Visual Basic .Net; but the language was so similar to C# that it just wasn't worth using. There was a joke that .Net was a "skinnable language."

BTW, there's a whole nitpicky/semantic argument that C# isn't null safe because of the null forgiving operator. That will probably come into play with G# if the null forgiving operator can be used from C# to pass null into G# code that doesn't expect it.

AdieuToLogic2• 7 days ago

20 years ago there was some momentum behind Visual Basic .Net; but the language was so similar to C# that it just wasn't worth using.

IronPython[0] and IronRuby[1] would like a word... Largely so they could be remembered.

0 - https://en.wikipedia.org/wiki/IronPython

1 - https://en.wikipedia.org/wiki/IronRuby

fulafel2• 7 days ago

And F# - though that's alive and well.

userbinator• 7 days ago

There was a joke that .Net was a "skinnable language."

I remember the MS documentation had sample code in all the variants of .NET languages they created (C#, F#, VB.NET), and of course there were decompilers that let you choose which one to target, with many other translation tools available between them.

ygra• 7 days ago

They still do.

Foobar8568• 7 days ago

The momentum behind VB.NET was mainly because most enterprises using VB6 assumed it was the natural replacement.

gnabgib2• 7 days ago

Your humble opinion? Nobody likes giving up what they know.. Perl, Python, Ruby, VB6 (can be moved to c#), Pascal (still relevant)

WorldMaker4• 6 days ago

To be fair, VB.NET itself also thought itself the natural replacement/direct continuation. Its compiler version started at 7.

fulafel2• 7 days ago

I think it would be more valuable if it had less concepts than C# but it doesn't seem clear if they succeeded in that.

truncate• 7 days ago

I wish README is clear whether they are using AI or not, and if so what the guidelines are. Not that anything wrong with using it, but given anyone with $$$ for tokens can do it, its nice to know what their process is etc etc. Gives me more confidence that its worth checking out.

afavour• 7 days ago

Agreed... the commit log looks very much AI generated to me. And the project was started on May 22 so it's just under two months old.

Not that either of these things is disqualifying but AI really has make it difficult to know how established a project actually is.

Bnjoroge• 7 days ago

It’s a pretty safe assumption that most recent projects use AI in some capacity. Models have gotten pretty good

hbcdbff2• 7 days ago

It’s slop

ed_elliott_asc• 7 days ago

Could you expand on that?

IshKebab• 7 days ago

This should be a standard section in READMEs now. I've started adding it to mine. Even if you don't use AI, please add a section saying that! It can be one sentence.

  # Use of AI

  No AI was used. / This is entirely written by Claude and I didn't even read the code. / ...

torginus3• 7 days ago

If you look at the list of contributors, you see Claude and Copilot, but on the other hand, You can see a huge, functional codebase going back to as far as 2024, so its safe to say its not vibecoded.

https://github.com/DavidObando/gsharp/tree/9579dd6626801f089...

Areading314• 7 days ago

New programming languages? Doesn't seem needed anymore

stevekemp3• 7 days ago

Things like Zig, D, Odin, Rust, etc, are outliers. Most new programming languages are used only by their creators.

It's hard for a new language to find its feet, and make a name for itself. Unless its created by a big company with a lot of clout and internal users. (e.g. Rust, Go).

People keep creating new languages because it's educational, interesting, and sometimes even fun. Doesn't mean they'll get used, and it doesn't mean they're pointless.

Of course you learn very little if you make an LLM write the damn thing. But that's a different story.

phplovesong2• 7 days ago

There is gleam that is popular, and not backed by a huge company. Then there is also lisette for Go, thats very similar but targets Go instead of the beam.

New languages have space, and its just stupid "to stick to the only one i ever tried", then you just end like a PHP dev who just refuses to learn anything other than PHP.

seabrookmx3• 7 days ago

Here I am wanting the opposite. I want C# compiled into a static binary like with the GoLang toolchain!

Maybe .NET AOT will get there one day..

sedatk• 7 days ago

What's missing in .NET AOT?

dotschnet• 7 days ago

That’s a dishonest question, take any code base >10000 slices, it will not work with aot ootb.

Read the docs of what’s missing, if you are honestly interested in what’s missing.

https://learn.microsoft.com/en-us/dotnet/core/deploying/nati...

Reflection, is one thing. Of course some runtime stuff are missing, but the problem is that no one is using source generators before trying out aot, so as soon you try aot you just meet a wall of compilation errors. Most people just want to be able parse a json file without jumping through hoops. Bad DX

seabrookmx3• 5 days ago

Lots of replies to this comment but a simple answer from my side: compatibility with ASP.NET attribute routing.

borland2• 7 days ago

I used it recently to write a useful utility related to OpenTelemetry file processing. .NET AOT produced a single-file static binary which is similar in size to what Go would produce, and can be dropped into any target system and run without dependencies, just like Go does.

It was nice. Feel free to take a look

https://github.com/OctopusDeploy/OtelImporter

PinkMilkshake• 7 days ago

It exists! https://flattened.net/

fabian2k3• 7 days ago

You don't need AOT for a single self-contained binary. This already works with C#, but it's still JIT-based.

seabrookmx3• 5 days ago

Self-contained != static compilation though. The self-contained binaries still have pretty poor startup time and are large since they contain the whole JIT.

jdw64• 7 days ago

Looks pretty good to me.

borland2• 7 days ago

Yuck. I like both Go and C# a lot, and use them both professionally.

In my experience the strengths of Go are mostly - Deployability via single-file static binaries - Simple syntax that anyone can learn (no exceptions, no classes or inheritance) - Wicked fast compile times

And the strengths of C# are - Powerful language with null-safety and lots of syntax sugar - Runtime-level coroutines so you don't need `async/await` everywhere

G# seems like it has the _worst_ of both worlds, not the best. It's fun to write compilers, and good on them for doing it, but no thank you for real use

rmuratov• 7 days ago

C# has single-file static binaries

littlecranky673• 7 days ago

Exactly. To add to this, is called ahead-of-time compilation, and bundles required parts of the .net runtime into the single-binary. Deployment targets thus don't need to ship any .net environment or libraries.

magicalhippo• 6 days ago

Yes but no. It's essentially a self-extracting executable, so adds significant start-up time. It also doesn't work in all cases, for example the database driver files to the DB we use aren't compatible with the single-file deployment method.

sideway• 7 days ago

And the strengths of C# are [...] Runtime-level coroutines so you don't need `async/await` everywhere

If I'm not mistaken, that isn't the case. Could you elaborate?

n4r9• 7 days ago

They might have meant to put that point in the Go section?

Quothling• 7 days ago

I've worked with C# for a decade, and Go for the past 5ish years and I think the biggest difference between them is in the philosophical design on implicity and explicity. I have a strong dislike for C# like languages these days, but it's not for technical reasons. I think C# is supperior to Go in many ways, but I absolutely hate the implicity in it's design, and this is a personal opinion that is not objective. In this context I can't imagine how you would create a mix of the two that wouldn't violate either approach. Looking at something like this:

@DllImport("libc", EntryPoint: "strlen", CharSet: CharSet.Ansi)

I would argue that they made something I suspect many Go developers will dislike. I know I absolutely hate it. If I wanted to do things like that I might as well use C#. Then again, these days I'm shifting more and more of my development to either Python (which is objectively an awesome language that also sucks) or Rust. While one of my favorite features of any programming language is the Go modules with single folders and upper and lower cases for private/public. I am becoming a fan of how rust does structs with impl methods.

Anyway...

mhh__3• 7 days ago

C# is a pretty bad language when you take away the stack it sits atop of. I do mostly like the async but developers put up with a lot of shit to e.g. use the msft networking stack and containers

anton_gogolev• 7 days ago

Care to elaborate on what would make C# a bad language?

Anvoker• 7 days ago

I feel the opposite. It is one of the genuinely competent languages out there, if you're the kind of person that isn't upset about it being a "kitchen sink". Instead, I feel like the ecosystem, community and reputation hold it back. There are nowhere as many useful and popular packages to reach for as Python for example. Unity3D always lags behind in runtime and language version and had amazingly bad package management -- this further hamstrung C#, because the language is never used in a vacuum.

aryehof• 7 days ago

Does this support new programming abstractions, or just another remix of existing ones?

captainbland• 7 days ago

I'm less familiar with Swift but from a design point of view Go and Kotlin have really different ergonomics. Kotlin leans in really hard to creating DSLs etc. whereas Go avoids all that stuff like the plague. To me this makes the tag line a little confusing, like what does this imply for the design of this language?

Kitajima• 7 days ago

I lived long enough to see a programming language called G#.

What a great era.

andyferris• 7 days ago

I was hoping from the tagline it would have sum types (rust-like payloads on enums, like Swift).

hbcdbff2• 7 days ago

“Width-bearing”, wow, Claude really loves that “bearing” suffix doesn’t he

vivzkestrel• 7 days ago

- stupid question: how do you make a programming language like this from scratch?

- what is the thought process that goes into making a programming language

- what is this field of study or discipline called?

- why do we have so many programming languages? what purpose do they intend to solve and how do we know what purpose a programming language was made for?

- for example, why was swift made if objective c exists and why was objective c made if c++ exists?

tinco• 7 days ago

When I was in university the course was called compiler construction. Making a language like G# is very simple and about the level that the final project of the course would be if the team was working together really well and went for maximum bonus points.

We have so many programming languages because it's a fun and relatively easy thing to start, and lots of people have differing opinions of how it should be done. Also making a programming language seems like a difficult thing from the outside so it has a certain allure.

Swift exists because objective c has archaic language design that modern developers reject. Objective C exists because as far as I know at the time smalltalk style object oriented programming was hip and C++ made the wrong decisions in their eyes. It could also be that C++ wasn't popular enough yet at that point for Apple to commit to it. In that period basically all major operating systems went different ways. The Unix derivatives went all in on plain C, Microsoft went C++ and Apple objective c, though I think OSX itself is plain C for the most part.

Scaevolus• 7 days ago

- it's easy to prompt an LLM to do it for you, especially if you're targeting a pre-existing runtime like CLR or transpiling to another language. previously you'd have to grind out the parser and compiler for a new language, but a lot of that work is mechanical

- "I want a language that works a little differently"

- programming language theory (PLT), generally

- languages are tools. the authors should explain what their languages are best suited for

- Obj C and C++ were both developed around the same time as extensions of C. Obj C was focused on message passing and Smalltalk's object system, while C++ was focused on adding as many abstractions as possible to C. Neither language has good support for avoiding null pointer dereferences, one of the primary things Swift addresses with its richer type system and Optionals.

Deukhoofd• 7 days ago

For your first two questions, I can't recommend Crafting Interpreters enough, it's probably one of the best entry-level books that goes into that entire process.

https://craftinginterpreters.com/

stevekemp3• 7 days ago

Making new programming languages is something a lot of people do for fun, and it's also covered in most CS degrees too, albeit briefly.

We have so many programming languages because they tend to have a particular niche in which they're useful. Many languages are still in use even though they're very old (C, FORTRAN, COBOL), and others just keep getting updated over time and have a large userbase (Java, Perl, Ruby, Python).

99.99% of all new programming languages never get a critical mass of users. People create a new language to learn something, and they're the only user. e.g. I've written a few FORTHs, have spent the past few weeks on writing a lisp compiler, and in the past wrote BASIC interpeters for fun.

If you want to make your own "crafting interpreters" is a good read:

https://craftinginterpreters.com/contents.html

But there are a million other tutorials on writing a simple lexer/parser/interpreter/compiler, and a lot of academic literature (e.g. The Dragon Book).

phplovesong2• 7 days ago

Why was c created when we had asm? Actually why even bother with asm when punch cards did the job just fine.

brabel• 7 days ago

how do you make a programming language like this from scratch?

Write a parser from your language’s syntax to an AST (Abstract Syntax Tree) which is the representation of the code in memory. Now write a function from the AST to the compiler output format. That can be some executable binary format (see https://en.wikipedia.org/wiki/Comparison_of_executable_file_...) or some other language, like C (a common target) or something made exactly for that like LLVM (used by clang and Rust), Java or C# bytecode if you don’t mind requiring a VM to run the application. I’ve written Java bytecode generators and it’s surprisingly easy! Getting a simple language off the ground is a lot of fun and not a huge challenge.

bjoli4• 6 days ago

i have made a language that xompiles to c#. I wrote a lexer. then a parser. then a type checker (hindley milner, function local so that top level functions must have type signatures) a match compiler.

the hardest part was what came next: the code generation. despite producing c# instead of MSIL. The features I use are: static and dynamic traits, pattern matching, and a concurrentML.

It is actually quite simple when you don't have to do closure conversion yourself.

rerdavies• 6 days ago

I've done that for transpilation from SAOL (an MPEG 4 historically curious language) to C++. It does make it incredibly easy to write the compiler.

The big drawback that I never managed to sort out is how to integrate with visual debuggers. How to generate GDB source mappings (or .PDB source mappings) that reference the original LanguageX source files.

So you end up with a toy language that is un-debuggable. Which is not nearly as much fun as it should be.

raphinou• 7 days ago

Is the familiar syntax so important? I learnt f# being used to algol syntax, and the syntax was not a hurdle.

peter_retief2• 7 days ago

I love Go but am not a fan of .NET

Have to ask what is the point of .NET is it even needed being the navel gazing MS fraternity?

tuwtuwtuwtuw• 7 days ago

C# is a great programming language. It's cross platform, and I personally find it fun and efficient to use.

According to Tiobe index and stack overflow developer survey, it's also a lot more used than Go, so there's that.

peter_retief2• 7 days ago

Yes even I have used C#

My anti MS is a reflex from many years of torment!

ctenb• 7 days ago

Looking at the code and the commit log, this is a large pile of slop

mapcars2• 7 days ago

Go, C# and .Net? And here I am wishing for typescript-like language for backend systems.

psd12• 7 days ago

F# is nice, i like it.

mapcars2• 7 days ago

Interesting, I have been skeptical about .net as a platform, is it really open and doesn't lock you with microsoft in any way?

YuechenLi2• 7 days ago

So... the verbosity of Go without the compile speed of Go? Go is not a language I would associate with ergonomics, and this doesn't even have most of modern C#'s best features: does xUnit.NET work? Does immutable records work? Do collection expressions work? Does LINQ work?

Calling a language with `let` instead of `const` and async/await and iterators and classes "Go" is plain just incorrect. This G# is more similar to TypeScript than Go.

The ONE feature that C# really needs is payload enums with `match` instead of C#'s current pattern matching with `switch` anyways, and Rust is more similar to Go anyways so why not copy from Rust instead? I'm honestly baffled.

orphea5• 7 days ago

  modern C#'s best features: does xUnit.NET work? Does immutable records work? Do collection expressions work? Does LINQ work?

xUnit and LINQ are not C# features, why should they not work in another .NET language?

tcfhgj• 7 days ago

Micro$oft's wiki:

Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language.

torginus3• 7 days ago

I don't find Go especially verbose - in fact, due to the economy of syntax, Go code without the usual syntax sugar features ends up similar in length to other curly brace languages. I tested this with C# and Typescript, where I migrated projects from these languages to Go - the overall volume of code stayed roughly the same.

BadBadJellyBean• 6 days ago

  err := do_something()
  if (err != nil) {
    return nil, err
  }

  err = do_something_else()
  if (err != nil) {
    return nil, err
  }

  err = do_something_more()
  if (err != nil) {
    return nil, err
  }

...

So very concise. And this is not even including the error wrapping that is recommended.

GoblinSlayer• 7 days ago

I think C# switch supports type matching.

mmusc• 6 days ago

https://learn.microsoft.com/en-us/dotnet/csharp/language-ref...

they're coming

YuechenLi2• 6 days ago

Yeah, I still don't understand why they don't just use enums and have to invent a special "union" keyword instead. C#'s enums are extremely underpowered to begin with and the syntax they designed here way more convoluted and uglier to say:

    enum Pet { 
    Cat,
    Dog,
    Bird
    }

    var description = Pet switch
    {
        Dog d => d.Name,
        Cat c => c.Name,
        Bird b => b.Name,
        _ => "no pet"
    }

The other issue is they introduced `null` to pattern matching on their union example when the whole point of pattern matching is that you can pretty much mostly remove `null` from the language altogether with Result<T, E> available, as Rust has shown.

cmoski• 7 days ago

for i in 1 ... 5 { sum = sum + i }

Means "for 1 to 4". Kill me now.

bjoli4• 6 days ago

if the language specifies all ranges to be the same this matters very little.

if a ranges are inclusive, you get used to it. if it is arbitrary it is awful.

bjoli4• 6 days ago

why doesn't anyone just jump the gun and introduce proper parallelism primitives? SML/NJ got it right in 1991. ocaml5.0 has domains and effect handlers.

why do people still accept CSP? It is simple to do some things in it, bit please just give me concurrentML with "simple" channels for that kind of work , and proper channels for any kind of hard stuff. I have had to write things in go that took me days to get straight that would have been 20 trivial lines in any concurrentML implementation.

G# – A modern .NET language with Go, Kotlin, and Swift ergonomics

Related Stories