In the text below, you refer to the “public” interface. Can I ask what you mean by “public” in this context?
John > On Oct 29, 2021, at 11:16 AM, Brian Beckman <[email protected]> wrote: > > I believe that run time will be the most plausible use case. I may write > macros that refer to struct-procedure names at macro-writing time, but I > don't expect to invoke the struct procedures at macro-expansion time. My > primary issue is "discoverability:" how can I find out the interface of any > struct? > > On Thursday, October 28, 2021 at 1:00:15 PM UTC-7 [email protected] wrote: > Are you intending to use the struct procedure names at compile time (such as > in a macro) or runtime? > > On Tuesday, October 26, 2021 at 5:02:46 PM UTC-7 [email protected] wrote: > I understand why structs are opaque, by default, but I want to discover the > public interface of some struct type, that is, a list of the procedures > defined by the struct. > > Here is an example. Suppose I want to find out all the procedures defined on > an instance of the syntax struct > > #'42 > > Dr. Racket shows an expander clicky that shows some formatted information > inside the instance : > > > > Uncapitializing the names in the display reveals the interface: > > (syntax-position #'42) ~~> 790 > (syntax-span #'42) ~~> 2 > (syntax-original? #'42) ~~> #t > > etc. > > I want to discover those procedure names in my racket program, not manually > by visually inspecting graphics in Dr Racket. > > I found this trick for structs that I define: > > #lang racket > (require (for-syntax racket/struct-info)) > (require racket/pretty) > > (struct foo (a b)) > (begin-for-syntax > (displayln > (extract-struct-info > (syntax-local-value > #'foo)))) > > ~~> > > > > but it doesn't work for the syntax type > > (begin-for-syntax > (displayln > (extract-struct-info > (syntax-local-value > #'syntax)))) > > ~~> > > > > I'd be grateful for advice and an example of how to get the interface of > "syntax" without Dr Racket and without grovelling docs. > > -- > 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]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/8e4ca03e-e276-4c42-a662-4fcf7c994387n%40googlegroups.com. -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/281a49f3-7870-48ca-888b-d3e5002b0f24%40mtasv.net.
