Locating a Nuget package from its fully qualified name

Question

I'm trying to compile the C# code from this post:

using System;
// < ... omitted ... >
using Roslyn.Compilers;
using Roslyn.Compilers.CSharp;
using Roslyn.Services;
using Roslyn.Services.CSharp;

• Usually, when I use pip or npm the package name is easily found from the FQN
• With nuget I can't find the corresponding package (neither with google search nor with Nuget search)

$ nuget install Roslyn.Compilers.CSharp # <--- use raw fqn, doesn't work         
# ... omitted ...
Unable to find package 'Roslyn.Compilers.CSharp'

$ nuget install Microsoft.Net.Compilers.Toolset  # <--- 1st result Nuget search
$ nuget install Microsoft.CodeAnalysis.Compilers # <--- 2nd result Nuget search
$ nuget install Microsoft.CodeAnalysis           # <--- 3rd result Nuget search

I (semi) blindly tried some other packages but none worked:

main.cs(5,7): error CS0246: The type or namespace name `Roslyn' could not be found. Are you missing an assembly reference?

How can I systematically infer the Nuget relevant package from the fqn?

Answer 1

The nuget package you are looking for is Microsoft.CodeAnalysis.CSharp. Add it to your project with:

dotnet add package Microsoft.CodeAnalysis.CSharp

Also, some things have changed, the code from the post you linked works with .NET 6 if changed like this:

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;

namespace gettingstarted2
{
    class Program
    {
        static void Main(string[] args)
        {
            SyntaxTree tree = CSharpSyntaxTree.ParseText(
                @"using System;
                using System.Collections;
                using System.Linq;
                using System.Text;

                namespace HelloWorld
                {
                    class Program
                    {
                        static void Main(string[] args)
                        {
                            Console.WriteLine(""Hello, World!"");
                        }
                    }
                }");

            var root = (CSharpSyntaxNode)tree.GetRoot();
        }
    }
}