No support for type parameters that extend types.

[rickyclarkson]

Foo = Bar | Baz // works fine

Foo< T > = Bar< T > | Baz // works fine

Foo< T extends CharSequence > = Bar< T > | Baz // doesn't parse

The following doesn't parse and could be hard. Also my real use case, from swingflow.

Progress< E extends Enum< E > & Localized > = InProgress(final int numerator, final int denominator, final E brief, final String detail) |
Complete(final E brief, final String detail) |
Failed(final int numerator, final int denominator, final E brief, final String detail)