Thank you for your kind responses. Your solutions are good ones but unfortunately don't fit my purpose. Imagine a mobile code scenario where you have no control of the definition of a closure. What I want to do is to be able to print the body of any incoming closure that arrives in a message. So if server A sends server B a closure (lambda () (displayln "hello world")), B could grab that incoming closure and capture it as the string "(lambda () (displayln "hello world"))" so it can be inspected before executing it. Does this make sense? How can I then construct a function procedure->string that transforms at runtime (without using macros) a closure's body to a string?
Thank you again and happy new year. Alegria On Tue, Dec 31, 2013 at 10:53 AM, Alexander D. Knauth <alexan...@knauth.org>wrote: > Yes, you can do it with a struct with the property prop:procedure. > > #lang racket > > (require rackunit) > > (struct my-proc (proc str) > #:property prop:procedure (struct-field-index proc)) > > (define f > (my-proc (lambda (x) (+ x 1)) > "(lambda (x) (+ x 1))")) > > (check-true (procedure? f)) > (check-equal? (f 1) 2) > (check-equal? (my-proc-str f) > "(lambda (x) (+ x 1))") > > (define-syntax-rule (my-lambda args body ...) > (my-proc (lambda args body ...) > (substring (~v '(lambda args body ...)) 1))) > > (define f2 > (my-lambda (x) (+ x 1))) > > (check-true (procedure? f2)) > (check-equal? (f2 1) 2) > (check-equal? (my-proc-str f2) > "(lambda (x) (+ x 1))") > > > On Dec 29, 2013, at 10:45 PM, Alegria Baquero wrote: > > Hello, > > is there any way to transform a function's body to a string such as > "(lambda(x)...)"? > > Thanks > > Alegria > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > > > -- --------------------------------------------------------------------------------------- PhD candidate Department of Informatics Donald Bren School of Information and Computer Sciences University of California, Irvine
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