Are Roslyn's ".WithFooToken()" calls superfluous?

Question

I'm trying out Roslyn's code-generation capabilities using LinqPad to run fragments. LinqPad's .Dump() extension method renders a formatted view of the object to the Result pane.

The code generated by http://roslynquoter.azurewebsites.net/ includes a lot of code that doesn't seem to do much other than add bloat. The following code outputs return null; whether the .WithFooToken(...) calls are commented out or not.

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

var syn =
    SyntaxFactory.ReturnStatement(
        SyntaxFactory.LiteralExpression(SyntaxKind.NullLiteralExpression)
//          .WithToken(SyntaxFactory.Token(SyntaxKind.NullKeyword))
    )
//  .WithReturnKeyword(
//      SyntaxFactory.Token(SyntaxKind.ReturnKeyword)
//  )
//  .WithSemicolonToken(
//      SyntaxFactory.Token(SyntaxKind.SemicolonToken)
//  )
;
syn.NormalizeWhitespace().ToFullString().Dump();

Are such calls optional for all languages or only for languages which have sensible defaults built into their Roslyn support libraries?

Answer 1

@svick's answer is correct. I just forgot to re-enable that code because Roslyn Scripting wasn't available.

Now that Scripting is public, I have re-enabled that code and updated the website: http://roslynquoter.azurewebsites.net/

Try out the website right now, and redundant calls like you mention above should be gone (they'll still appear when they're needed to modify trivia/comments/etc).

Answer 2

Yes, in simple cases, those calls are not necessary. The code of RoslynQuoter has the RemoveRedundantModifyingCalls option, which I believe is supposed to do exactly what you want. But it's not implemented, the only usage is commented out:

private void AddModifyingCall(ApiCall apiCall, MethodCall methodCall)
{
    // TODO: this needs scripting
    ////if (RemoveRedundantModifyingCalls)
    ////{
    ////    var before = Evaluate(apiCall, UseDefaultFormatting);
    ////    apiCall.Add(methodCall);
    ////    var after = Evaluate(apiCall, UseDefaultFormatting);
    ////    if (before == after)
    ////    {
    ////        apiCall.Remove(methodCall);
    ////    }
    ////}

    apiCall.Add(methodCall);
    return;
}