Allow creating full stand-alone C# programs in a single .cs

[olfek]

Reopening #3502 by @mythz here

Idea 💡
#3502 (comment)

Be practical everyone ...

We want:

dotnet run main.cs

Without needing to specify any package references.

1. dotnet in a script mode parses the using statements and looks for relevant packages in the global .nuget packages folder.
2. dotnet passes main.cs to the Roslyn compiler along with references to the relevant packages found in the global .nuget packages folder.
3. dotnet program runs executable emitted by Roslyn compiler.
4. Profit

[bernd5]

It is not actually a language but a tooling thing.
Maybe the runtime or sdk repo would be better

[olfek]

can this be transferred there?

[olfek]

https://github.com/dotnet/sdk

[olfek]

@marcpopMSFT ⬆️⬆️⬆️

[marcpopMSFT]

We don't use discussions in the SDK repo so I can't just transfer. I know that this suggestion has come up before but I can't seem to find a related issue. CC @richlander and @baronfel in case they are aware of a tracking issue or could write one up in the SDK repo.

[TahirAhmadov]

https://www.cs-script.net/

[marcospgp]

Looking into this now and it seems like there are ways to run C# standalone scripts, at least according to ChatGPT (not incredibly official). Is there documentation available on this maybe?

[colejohnson66]

AFAIK, there are no official plans to add scripting support to C#. The best we can get now is top-level statements in a Program.cs file. If you want scripting, CS-Script exists. LINQPad is also pretty neat. It can handle single expressions all the way to full programs. It does come with a pretty hefty cost, however. Lastly, for a "REPL", dotnet-script is great.

[sharpchen]

for a "REPL", dotnet-script is great.

Consider trying out CSharpRepl as well.

[DamianEdwards]

This is now available in .NET 10 preview 4: https://www.youtube.com/watch?v=98MizuB7i-w

[TahirAhmadov]

This is such an important addition. Kudos to the team for working on this. C# is a great language and needs to be easy to teach to beginners. Keep them coming 👍

[The-Futurist]

Very helpful stuff.