I'm not sure what you mean by "adopt the binding of `private-proc`", but besides the directions mentioned by others, it sounds like `rename-out` might be relevant:
#lang racket (module inner racket (provide (rename-out [private-proc public-proc])) (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" At Wed, 26 Feb 2014 10:54:41 -0800, Matthew Butterick wrote: > 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 ____________________ Racket Users list: http://lists.racket-lang.org/users
