Thank you. Maybe I can make the question a tiny bit less dumb (though still really dumb).
In this example, when I use the syntax macro 'public-proc', it keeps the 'private-proc' binding from the 'inner' submodule. Q: How could I invoke 'public-proc' for its syntax-generating effect in the main module, yet have it adopt the binding of 'private-proc' in the main module? I gather roughly that it requires tampering with the lexical information of the syntax objects. Then things get hazy. ;;;;;;;;;;;;;;;;;;;;;;;;; #lang racket (module inner racket (provide public-proc) (define-syntax-rule (public-proc x) (private-proc x)) (define (private-proc x) (format "Inner private proc says ~a" x))) (require 'inner) (define (private-proc x) (format "Outer private proc says ~a" x)) (syntax->datum (expand #'(public-proc 'hi))) ;> '(#%app private-proc 'hi) (public-proc 'hi) ;> "Inner private proc says hi" (syntax->datum (expand #'(private-proc 'hi))) ;> '(#%app private-proc 'hi) (private-proc 'hi) ;> "Outer private proc says hi" ;;;;;;;;;;;;;;;;;;;;;;;;; On Feb 26, 2014, at 10:22 AM, Matthias Felleisen <[email protected]> wrote: > > That's precisely the behavior you want: > -- what's exported is the public name, which would usually check/do things > before it calls private > -- while the unprotected private one is not provided and should not be > visilble. > > How does the mechanics work? Well it delivers path names to these private > identifier that in principle you can find too. So you can get around > provided/not-provided but you don't want to > > -- Matthias > > > > > > > On Feb 26, 2014, at 11:51 AM, Matthew Butterick <[email protected]> wrote: > >> In this example, why can syntax produced via macro reach the private >> function, while the ordinary syntax cannot? >> >> >> ;;;;;;;;;;;;;;;;;;;;;;;; >> ;; one.rkt >> #lang racket/base >> >> (provide public-proc) >> >> (define (private-proc x) >> (format "The private proc says ~a" x)) >> >> (define-syntax-rule (public-proc x) >> (private-proc x)) >> ;;;;;;;;;;;;;;;;;;;;;;;; >> >> ;;;;;;;;;;;;;;;;;;;;;;;; >> ;; two.rkt >> #lang racket/base >> (require "one.rkt") >> ;;;;;;;;;;;;;;;;;;;;;;;; >> >> Running two.rkt: >>> (public-proc 'hi) >> "The private proc says hi" >>> (private-proc 'hi) >> private-proc: undefined >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users > ____________________ Racket Users list: http://lists.racket-lang.org/users
