On Wed, Apr 15, 2015 at 9:35 PM, Alexander D. Knauth <[email protected]> wrote: > > On Apr 15, 2015, at 2:29 PM, Jon Zeppieri <[email protected]> wrote: > >> I'm trying to provide a struct, the struct type of which uses >> prop:procedure and prop:match-expander, and I'd like the procedure to >> have a contract. >> >> If I simply (provide <identifier>) > > Is this identifier the constructor function, or an instance of this struct? > If it’s the constructor function, then couldn’t you use (provide > (contract-out [struct id ([field contract] …)])) for that? > If it’s an instance, then are you doing something different to define it as a > transformer binding? >
It's an instance of a struct. Here's the background: I have a struct type, created with `struct`, which has its own constructor and match expander. However, I don't want to use that constructor or match expander as part of the public interface. (The struct contains some fields that should be treated as private.) Now, the only way I know to provide a single identifier that can act as both a struct constructor and a match expander is to use a struct. So, in this case, I need to use a *different* struct type, an instance of which can be used, on one hand, as a procedure to construct an instance of the original struct type, and on the other, as a match expander (also for the original struct type). -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
