Thanks Jens and Ryan for your answers! I’ll experiment. — Éric
> On Aug 10, 2020, at 11:13 AM, Ryan Culpepper <[email protected]> wrote: > > You can use the functions from macro-debugger/expand to do this (within > limits). Here's a very rough example program that reads one term from stdin > and shows its expansion with the given hiding policy (discarding hygiene > information---beware). > > usage: racket expand.rkt < your-example-file.rkt > > Ryan > > > On 8/10/20 3:44 PM, Éric Tanter wrote: >> Hi, >> I’d like to use the Racket macro expander to translate programs from a given >> source language to a target language (both scheme-ish). >> However, the expansion that `raco expand` does is too violent for my >> purposes---I would need a way to specify macro hiding (as in the macro >> stepper), in order to control the level of abstraction of the expanded code. >> Is that possible? >> [see example below] >> Thanks, >> — Éric >> ; test.rkt >> (define-syntax-rule (swap x y) >> (let ([tmp x]) >> (set! x y) >> (set! y tmp))) >> (define a 10) >> (define b 20) >> (swap a b) >> ; I’d like to obtain: >> …prelude… >> (define a 10) >> (define b 20) >> (let ([tmp a]) >> (set! a b) >> (set! b tmp))) >> ; but raco expand gives me the full story: >> (module test play >> (#%module-begin >> (module configure-runtime '#%kernel >> (#%module-begin (#%require racket/runtime-config) (#%app configure >> '#f))) >> (#%provide b swap a) >> (define-syntaxes >> (swap) >> (lambda (user-stx) >> (let-values (((arg) user-stx)) >> (let-values (((rslt) >> (#%app >> (lambda (e) >> (if (#%app stx-pair? e) >> (if (#%app (lambda (e) null) (#%app stx-car e)) >> (#%app >> (lambda (e) >> (if (#%app stx-pair? e) >> (#%app >> cons/#f >> (#%app stx-car e) >> (#%app >> (lambda (e) >> (if (#%app stx-pair? e) >> (let-values (((mh) (#%app stx-car >> e))) >> (if mh >> (if (#%app >> stx-null/#f >> (#%app stx-cdr e)) >> mh >> '#f) >> '#f)) >> '#f)) >> (#%app stx-cdr e))) >> '#f)) >> (#%app stx-cdr e)) >> '#f) >> '#f)) >> arg))) >> (if rslt >> (let-values (((sc1) (#%app unsafe-car rslt)) >> ((sc2) (#%app unsafe-cdr rslt))) >> (let-values () >> (#%app >> syntax-protect >> (let-values (((loc) (#%app check-loc 'syntax/loc user-stx))) >> (#%app >> t-subst >> loc >> (quote-syntax (let _ (set! _ _) (set! _ tmp))) >> '(1 recur 2 recur 3) >> (#%app >> t-resyntax >> '#f >> (quote-syntax STX) >> (#%app >> t-list >> (#%app t-subst '#f (quote-syntax (tmp _)) '(1) sc1))) >> (#%app list '(1 2) sc1 sc2) >> (#%app list '(1) sc2)))))) >> (let-values (((rslt) (#%app (lambda (e) null) arg))) >> (if rslt >> (let-values () >> (let-values () (#%app pattern-failure user-stx '(x y)))) >> (#%app raise-syntax-error '#f '"bad syntax" arg)))))))) >> (define-values (a) '10) >> (define-values (b) '20) >> (#%app >> call-with-values >> (lambda () (let-values (((tmp) a)) (set! a b) (set! b tmp))) >> print-values))) >> -- >> 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] >> <mailto:[email protected]> >> <mailto:[email protected] >> <mailto:[email protected]>>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/racket-users/94E20736-F1F7-4073-B3FA-505ADD71DB4F%40dcc.uchile.cl >> >> <https://groups.google.com/d/msgid/racket-users/94E20736-F1F7-4073-B3FA-505ADD71DB4F%40dcc.uchile.cl> >> >> <https://groups.google.com/d/msgid/racket-users/94E20736-F1F7-4073-B3FA-505ADD71DB4F%40dcc.uchile.cl?utm_medium=email&utm_source=footer >> >> <https://groups.google.com/d/msgid/racket-users/94E20736-F1F7-4073-B3FA-505ADD71DB4F%40dcc.uchile.cl?utm_medium=email&utm_source=footer>>. > > -- > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/767ebe77-95ed-d9f7-4d00-6391482d15a9%40gmail.com > > <https://groups.google.com/d/msgid/racket-users/767ebe77-95ed-d9f7-4d00-6391482d15a9%40gmail.com>. > <expand.rkt> -- 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/847A9DD6-A5BE-42EA-BE0F-290792023E49%40dcc.uchile.cl.
