The following program should work. It uses a "syntax parameter" to reserve the name bar, then redirects that name to the argument to the lambda inside each use of foo. The reference material on syntax parameters is at:
http://docs.racket-lang.org/reference/stxparam.html #lang racket (require racket/stxparam) (define-syntax-parameter bar (make-set!-transformer (lambda (stx) (raise-syntax-error #false "cannot use bar except in an argument to foo" stx)))) (define-syntax-rule (foo form ...) ((lambda (arg) (syntax-parameterize {[bar (make-rename-transformer #'arg)]} form ...)) "ARG")) (foo "Hello") (foo bar) -- Carl Eastlund On Fri, Sep 16, 2011 at 3:46 PM, Daniel MacDougall <[email protected]> wrote: > Is there any way to define a macro that expands out to a lambda, and then > access the arguments passed to that lambda from outside the macro in the > calling context? > Here's an example of what I mean: > > #lang racket > > (define-syntax-rule (foo form ...) > ((lambda (bar) form ...) "ARG")) > > (foo "Hello") ; => returns "Hello" > > (foo bar) ; => expand: unbound identifier in module in: bar > > > I'd like access to the "bar" argument on the last line. Is this possible > with Racket macros? > Thanks, > Daniel _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
