Getting all public constants from the main and nested classes

Question

I wrote this recursive function to get all constants from a class and its subclasses. Can it be simplified?

private static IEnumerable<FieldInfo> GetPublicConstants(Type type)
{
 var subtypes = type.GetNestedTypes(BindingFlags.Public);
 foreach (var subtype in subtypes)
 {
 foreach (var constant in GetPublicConstants(subtype))
 {
 yield return constant;
 }
 }
 var publicStaticFields = type.GetFields(BindingFlags.Public |
 BindingFlags.Static | BindingFlags.FlattenHierarchy)
 .Where(fi => fi.IsLiteral && !fi.IsInitOnly);
 foreach (var fieldInfo in publicStaticFields)
 {
 yield return fieldInfo;
 }
}

For example, it would return 6 constants for the following class:

public static class MyClass
{
 public const string AAA = "";
 public static class A
 {
 public const string Aaaaa = "";
 public static class AB
 {
 public const string ABaaa = "";
 }
 }
 public static class B
 {
 public const string Baaa = "";
 public const string Bbbb = "";
 }
 public static class C
 {
 public const string Caaa = "";
 }
}

What I don't like is the fact I'm having 2 loops where I yield return 1 item because of inability to yield return a list of items.

Answer 1

How about this:

private static IEnumerable<FieldInfo> GetPublicConstants(Type type)
{
 return GetPublicClassConstants(type)
 .Concat(type.GetNestedTypes(BindingFlags.Public).SelectMany(GetPublicConstants));
}
private static IEnumerable<FieldInfo> GetPublicClassConstants(Type type)
{
 return type
 .GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy)
 .Where(fi => fi.IsLiteral && !fi.IsInitOnly);
}

OR, as I do enjoy playing PGA Pro Code Golf:

private static IEnumerable<FieldInfo> GetPublicConstants(Type type)
{
 return type
 .GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy)
 .Where(fi => fi.IsLiteral && !fi.IsInitOnly)
 .Concat(type.GetNestedTypes(BindingFlags.Public).SelectMany(GetPublicConstants));
}

• Иван Грозный: sorry, didn't understand the PGA reference however 2nd solution is ace!
• Jesse C. Slicer: @Tsar "Professional Golfers Association" and code golf is the art/game of making the code as small as possible.