[plt-scheme] namespace-variable-value

That's it.  Thanks!

Wayne
On Fri, Apr 27, 2007 at 08:26:02PM +0200, jos koot wrote:
> Hi Wayne
> Is this what you want?
> 
> (module lang1 mzscheme
>   (provide (all-defined)
>            (all-from mzscheme))
>   (define f 1))
> 
> (module test1 lang1
>   (provide (all-defined))
>   (define (test1)
>     (printf "~s~n"
>      (namespace-variable-value 'f #t (lambda () 'undefined)
>      (module->namespace 'lang1)))))
> 
> (require test1)
> (test1) ; display 1
> 
> (module lang2 mzscheme (provide (all-from mzscheme)))
> 
> (module test2 lang2
>   (provide (all-defined))
>   (define (test2)
>     (printf "~s~n"
>     (namespace-variable-value 'f #t (lambda () 'undefined)
>     (module->namespace 'lang2)))))
> 
> (require test2)
> (test2) ; --> display undefined
> 
> Jos
> 
> ((((lambda(x)((((((((x x)x)x)x)x)x)x)x))
>     (lambda(x)(lambda(y)(x(x y)))))
>    (lambda(x)(x)x))
>   (lambda()(printf "Greetings, Jos~n"))))
>   ----- Original Message ----- 
>   From: support at taxupdate.com
>   To: jos koot
>   Cc: plt-scheme at list.cs.brown.edu
>   Sent: Friday, April 27, 2007 2:37 PM
>   Subject: Re: [plt-scheme] namespace-variable-value
> 
> 
>   Jos,
> 
>   On Fri, Apr 27, 2007 at 07:30:26PM +0200, jos koot wrote:
>   > Module level variables can be assigned to only by the module itself. In this way the writer of a module is assured that the user 
> of
>   > the module cannot corrupt the variables.
> 
>   It's not clear to me whether this answers the question I'm trying to ask.  Here's
>   the original code:
> 
>   (module lang mzscheme
>     (provide (all-defined)
>              (all-from mzscheme))
>     (define f 1))
> 
>   (module test lang
>     (provide (all-defined))
>     (provide (all-from lang)
>     (define (test1)
>       (display (namespace-variable-value 'f))))
> 
>   (require test)
>   (test1)
> 
>   I don't want to set a module-level variable outside of the module, I want
>   to test whether it has been defined.  I expected the namespace-variable-value
>   call to use mapping (the default) to see that f has been imported.  Am I
>   misunderstanding how namespace-variable-value works?
> 
>   Wayne