Don't generate docs for private types. Cuts doc generation time in half.

lib/dartdoc/dartdoc.dart

Index: lib/dartdoc/dartdoc.dart
diff --git a/lib/dartdoc/dartdoc.dart b/lib/dartdoc/dartdoc.dart
index 22456bad8209c0fecffa53db3c7d36763535f996..90d7e1004f9c3adc7536797cda6a47624e8a798a 100644
--- a/lib/dartdoc/dartdoc.dart
+++ b/lib/dartdoc/dartdoc.dart
@@ -532,7 +532,9 @@ class Dartdoc {
     endFile();
 
     for (final type in library.types.getValues()) {
-      if (!type.isTop) docType(type);
+      if (type.isTop) continue;
+      if (type.name.startsWith('_')) continue;

[nweiz, 2012/03/15 21:04:43]

I personally like using continue here, but isn't it contrary to the preferred
style?

[Bob Nystrom, 2012/03/15 22:14:28]

I don't think so. I know some people aren't a fan of continue, but I'm not aware
of any prescription against using it.

+      docType(type);
     }
   }