Nested types for F#
I don't think F# supports nested type definitions yet.
The idea was posted here:
Two other references on nested types:
Gauthier Segay commented
I concur that we need fuller support of .net type system.
James Freiwirth commented
This would be great. Also allowing 'open' statements in the same way that you can with nested modules would help to make large codebases more organised and easier to maintain.