Hi Alfred, See
http://docs.racket-lang.org/guide/eval.html#(part._namespaces) Matthew At Tue, 14 May 2013 07:01:51 -0400, Alfred Zhong wrote: > Hi Racket experts, > > I am reading SICP and trying this piece of code using Racke: > > (define (definition-value exp) > (if (symbol? (cadr exp)) > (caddr exp) > (make-lambda > (cdadr exp) ; formal parameters > (cddr exp) ; body > ) > ) > ) > > (define (make-lambda parameters body) > (cons 'lambda (cons parameters body)) > ) > > ( (eval (definition-value '(define (double x) (+ x x))) ) 10) > > In REPL, it return 20 with no problem. > > However, if I put it into a file and use racket command to run it (with > #lang scheme in the file) > > it complains: > compile: unbound identifier (and no #%app syntax transformer is bound) at: > lambda in: (lambda (x) (+ x x)) > > Do you have any idea what happened there? How can I solve this problem? > > Thanks, > Alfred > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
