[racket] init and init-field

On 2013-01-09 16:37:17 -0500, Asumu Takikawa wrote:
> Fields are always public unless you use `define-local-member-name`, so
> if you don't want to expose your state you are better off with the
> internal definition (which is private). There may be other reasons too.

To be a bit more precise, a field declared with `field`/`init-field` is
always public. A field declared with `define` is private.

Cheers,
Asumu