TypeNameFormatter.Sources 1.0.0-beta

TypeNameFormatter is a small .NET library for formatting type names à la C#.

What is this good for?

Have you ever stumbled over the cryptic formatting of Type objects?

var someType = typeof(IEnumerable<int[]>);

Console.WriteLine(someType);
// => System.Collections.Generic.IEnumerable`1[System.Int32[]]

If you'd rather see something that looks more like a C# type name, then this library might be for you:

using TypeNameFormatter;

var someType = typeof(IEnumerable<int[]>);

Console.WriteLine(someType.GetFormattedName());
// => IEnumerable<int[]>

Formatting any Type involves more special cases than you might expect (such as generic types, nested types, multi-dimensional and jagged arrays, by-reference and pointer types). This library deals with all of those, so that you don't have to.

How do I use it?

By importing the TypeNameFormatter namespace, the following extension methods become available:

• stringBuilder.AppendFormattedName(Type type, [TypeNameFormatOptions options]):
  Appends a C#-formatted type name to the given StringBuilder.

• type.GetFormattedName([TypeNameFormatOptions options]):
  Returns a C#-formatted type name as a string. (This is a convenience method that does exactly the same as the above, using a throw-away StringBuilder.)

Both methods allow you to specify any combination of the following TypeNameFormatOptions flags:

• GenericParameterNames:
  Parameter names of an open generic type should be included. (For example, IEnumerable˂T˃ instead of IEnumerable˂˃. Note that this setting does not affect closed generic types; their arguments are always included.)

• Namespaces:
  Namespaces should be included. (For example, System.Action instead of Action.)

• NoKeywords:
  Primitive types should not be mapped to their corresponding C# language keywords. (For example, Int32 instead of int.)

• NoNullableQuestionMark: Nullable types should not be formatted using C# question mark syntax. (For example, Nullable˂int˃ instead of int?.)

But it doesn't format <some type> correctly!

If you think you've found a bug, please raise an issue so it can be looked into. (Make sure to mention the type that doesn't get formatted as expected.)

Alternatives

• If you're targeting the .NET Framework, you can use good old System.CodeDom (which isn't particularly fast, however):

  using Microsoft.CSharp;
  using System.CodeDom;
  
  static string GetFormattedName(this Type type)
  {
       using (var provider = new CSharpCodeProvider())
       {
           var typeReference = new CodeTypeReference(type);
           return provider.GetTypeOutput(typeReference);
       }
  }
  

• You could perhaps use Microsoft's .NET Compiler Platform (Roslyn), but that is a large library that can do much more than is needed.