[mike_hearn]

C# and Go are direct competitors and the advantages of Go that were cited are all features of C# as well, except the lack of top level functions. That's clearly not an actual problem: you can just define a class per file and make every method static, if that's how you like to code. It doesn't require any restructuring of your codebase. There's also no meaningful difference in platform support, .NET AOT supports Win/Mac/Linux on AMD64/ARM i.e. every platform a developer might use.

He clearly knows all this so the obvious inference is that the decision isn't really about features. The most likely problem is a lack of confidence in the .NET team, or some political problems/bad blood inside Microsoft. Perhaps he's tried to use it and been frustrated by bugs; the comment about "battle hardened" feel like where the actual rationale is hiding. We're not getting the full story here, that's clear enough.

I'm honestly surprised Microsoft's policies allowed this. Normally companies have rules that require dogfooding for exactly this reason. Such a project is not terribly urgent, it has political heft within Microsoft. They could presumably have got the .NET team to fix bugs or make optimizations they need, at least a lot easier than getting the Go team to do it. Yet they chose not to. Who would have any confidence in adoption of .NET for performance sensitive programs now? Even the father of .NET doesn't want to use it. Anyone who wants to challenge a decision to adopt it can just point at Microsoft's own actions as evidence.

[neonsunset]

Thanks, this is a good way to frame it, someone else also phrased similar sentiment which I'm in total agreement with: https://x.com/Lon/status/1899527659308429333

It is especially jarring given that they are a first-party customer who would have no trouble in getting necessary platforms supported or projects expedited (like NativeAOT-LLVM-WASM) in .NET. And the statements of Anders Hejlsberg himself which contradict the facts about .NET as a platform make this even more unfortunate.

[mike_hearn]

I wonder if there's just some cultural / generational stuff happening there too. The fact that the TS compiler is all about compiling a highly complex OOP/functional hybrid language yet is said to use neither objects nor FP seems rather telling. Hejlsberg is famous for designing object oriented languages (Delphi, C#) but the Delphi compiler itself was written largely in assembly, and the C# compiler was for a very long time written in C++ iirc. It's possible that he just doesn't personally like working in the sort of languages he gets paid to design.

There's an interesting contrast here with Java, where javac was ported to Java from C++ very early on in its lifecycle. And the Java AOT compiler (native image) is not only fully written in Java itself, everything from optimizations to code generation, but even the embedded runtime is written in Java too. Whereas in the .NET world Roslyn took quite a long time to come along, it wasn't until .NET 6, and of course MS rejected it from Windows more or less entirely for the same sorts of rationales as what Anders provides here.

[neonsunset]

> Roslyn

It was introduced back then with .NET Framework 4.6 (C# 6) - a loong time ago (July 2015). The OSS .NET has started with Roslyn from the very beginning.

> And the Java AOT compiler (native image) is not only fully written in Java itself, everything from optimizations to code generation, but even the embedded runtime is written in Java too.

NativeAOT uses the same architecture. There is no C++ besides GC and pre-existing compiler back-end (both ILC and RyuJIT drive it during compilation process). Much like GraalVM's Native Image, the VM/host, type system facilities, virtual/interface dispatch and everything else it could possibly need is implemented in C# including the linker (reachability analysis/trimming, kind of like jlink) and optimizations (exact devirtualization, cctor interpreter, etc.).

In the end, it is the TypeScript team members who worked on this port, not Anders Hejlsberg himself, which is my understanding. So we need to take this into account when judging what is being communicated.

[magicalist]

> In the end, it is the TypeScript team members who worked on this port, not Anders Hejlsberg himself, which is my understanding

no? https://github.com/microsoft/typescript-go/graphs/contributo...

[neonsunset]

Ah, I see. Thanks for the clarification. Well, doubly unfortunate then. I wonder if we'll ever know what happened behind the scenes.

[mike_hearn]

Ah C# 6 not .NET 6, thanks for the correction. Cool to hear that the NativeAOT stuff follows the same path.

[i_s]

Yea, I came here to say the same thing. Anders' reasons for not going with C# all seem either dubious or superficial and easily worked around.

First he mentions the no classes thing. It is hard to see how that would matter even for automated porting, because like you said, he could just use static classes, and even do a static using statement on the calling side.

Another one of his reasons was that Go was good at processing complex graphs, but it is hard to imagine how Go would be better at that than C#. What language feature that Go has, but C# does not supports that? I don't think anyone will be able to demonstrate one. This distinction makes sense for Go vs Rust, but not for Go vs C#.

As for the platform / AOT argument, I don't know as much about that, but I thought it was supposed to be possible now. If it isn't, it seems like it would be better for Microsoft to beef that up than to allow a vote of no confidence to be cast like this.