Without have read this carefully, are you maybe looking for https://docs.racket-lang.org/reference/syntax-util.html#%28def._%28%28lib._racket%2Fsyntax..rkt%29._format-id%29%29? If you just pass string->symbol and then use datum->syntax you will get binding errors. Tom
On Tue, Aug 13, 2019 at 7:03 PM Jonathan Simpson <jjsim...@gmail.com> wrote: > I have a bug I'm trying to fix in #lang magic( > https://github.com/jjsimpso/magic). I'm pretty sure I know what the cause > is and I know what I want to do, but I don't know how to do it. The > situation is this: > > In the following magic code, a new function(called a named query in magic) > tga-image is defined and later used inside the definition of the function > test-scope. The issue is that tga-image is an unbound identifier in > test-scope. If tga-image is used outside of a function there isn't a > problem because the syntax object passed to use has the binding. What I > would like to do is define tga-image at the top level. When test-scope is > being expanded it doesn't find the binding for tga-image and tags it with > #%top, so I think putting tga-image at the top level will solve my problem. > I also think that this is not a bad solution for my use case. > > #lang magic > > > # display tga bitmap image information > 0 name tga-image > >2 byte <34 Targa image data > > > 0 name test-scope > >2 byte <34 Test Scope > >0 use tga-image > > After parsing, this code becomes: > > (module magic-mod magic/expander > (magic > #f > #f > (named-query > (name-line (offset 0) (name-type "name") "tga-image") > (level) > (line (offset 2) (type (numeric "byte")) (test (numtest "<" 34)) (message > "Targa image data"))) > (named-query > (name-line (offset 0) (name-type "name") "test-scope") > (level) > (line (offset 2) (type (numeric "byte")) (test (numtest "<" 34)) (message > "Test Scope")) > (level) > (line (offset 0) (type (use "use")) (test (use-name "tga-image")))))) > > This is the most relevant code in my expander (I highlighted creation of > name's binding in red): > > (define-syntax (named-query stx) > (syntax-case stx (name-line) > [(_ (name-line (_ 0) (_ "name") magic-name)) > (with-syntax ([name (datum->syntax stx (string->symbol > (syntax->datum #'magic-name)))]) > #'(define name > (lambda (new-offset) (void))))] > [(_ (name-line (_ 0) (_ "name") magic-name) . rst) > (with-syntax ([name (datum->syntax stx (string->symbol > (syntax->datum #'magic-name)))] > [modified-rst (cons (datum->syntax #'rst > always-true-line) #'rst)]) > #'(define name > (lambda (new-offset) > (syntax-parameterize ([name-offset (make-rename-transformer > #'new-offset)]) > ;(printf "name: offset = ~a~n" name-offset) > (query . modified-rst)))))])) > > (define-syntax (magic-module-begin stx) > (define (query? expr) > (if (and (pair? expr) > (equal? (car expr) 'query)) > #t > #f)) > (define (named-query? expr) > (if (and (pair? expr) > (equal? (car expr) 'named-query)) > #t > #f)) > (define (wrap-with-delimiter-print expr) > (list 'when* expr '(printf "*** "))) > > (let ([exprs (cdadr (syntax->datum stx))]) > ;(display queries) > (let ([queries (filter query? exprs)] > [named-queries (filter named-query? exprs)]) > #`(#%module-begin > #,@named-queries > (define (magic-query) > (or #,@queries)) > (define (magic-query-run-all) > ; any-true? creates a binding for last-level-offset which we > probably don't want here. investigate. > (any-true? #,@(map wrap-with-delimiter-print queries))) > (provide magic-query magic-query-run-all))))) > > The full code is at > https://github.com/jjsimpso/magic/blob/master/expander.rkt. > > If there isn't an easy way to pass the top level syntax object into > named-query, then I may have to do something with syntax parameters. I > think that would be more complicated since I'm potentially defining lots of > functions. > > Any help is appreciated! I thought this would be an easy one, but I've > spent a while on it already. Hopefully there is a simple solution. > > -- Jonathan > > -- > 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 racket-users+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/ee664882-1dec-4bb8-b66b-bd6ee80316dc%40googlegroups.com > <https://groups.google.com/d/msgid/racket-users/ee664882-1dec-4bb8-b66b-bd6ee80316dc%40googlegroups.com?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 racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CA%2BG3_PO6OrRfFaqrCTrO%3D7a904TGp3ROuyq6m3Gbco%2BC5XPYxw%40mail.gmail.com.
