[plt-scheme] How to get the source of procedure?

Thanks all for the replies.  I am interested on source code  
inspection from the point of view of understanding how a particular  
procedure was implemented. I understand than on relying on the  
implementation of procedure may breaks the contract. However, I think  
that inspecting is good for learning.

-- Jaime

On May 16, 2006, at 4:45 AM, Dave Herman wrote:

> Here is a module that defines a special lambda form that allows you  
> to create a procedure with a documentation string and its source  
> code represented as an S-expression.
>
> Let me warn you about the perils of source code inspection, though.  
> In JavaScript, you can access the source code of any function as a  
> string. As a result, the browser vendors get bug reports every time  
> they make even the slightest changes to the implementation of any  
> function: users have written programs that rely on the exact  
> representation of the source code, so changes to the implementation  
> break the users' code -- sometimes even as mundane as whitespace  
> changes! The situation is only marginally better with an S- 
> expression representation.
>
> Executive summary: violate abstraction boundaries, and you'll get  
> what you deserve. :)
>
> I'll add this to the Scheme Cookbook.
>
> Dave
>
> ;; --
>
> (module doc-lambda mzscheme
>   (define-values (struct:doc-lambda make-doc-lambda doc-lambda? doc- 
> lambda-ref doc-lambda-set!)
>     (make-struct-type 'doc-lambda #f 3 0 #f null #f 0))
>
>   (define doc-lambda-proc (make-struct-field-accessor doc-lambda- 
> ref 0 'proc))
>   (define doc-lambda-doc (make-struct-field-accessor doc-lambda-ref  
> 1 'doc))
>   (define doc-lambda-src (make-struct-field-accessor doc-lambda-ref  
> 2 'src))
>
>   (define (procedure-doc x)
>     (and (doc-lambda? x)
>          (doc-lambda-doc x)))
>
>   (define (procedure-source x)
>     (and (doc-lambda? x)
>          (doc-lambda-src x)))
>
>   (define-syntax doc-lambda
>     (syntax-rules ()
>       [(_ doc-string args body0 body1 ...)
>        (let ([doc-string-v doc-string])
>          (make-doc-lambda
>           (lambda args body0 body1 ...)
>           doc-string-v
>           `(doc-lambda ,doc-string-v args body0 body1 ...)))]))
>
>   (provide doc-lambda procedure-doc procedure-source))
>
> ;; --
>
> Dave
>