[plt-scheme] determine free variables

That's interesting.

A note though: that implementation doesn't handle
letrec-syntaxes+values which isn't in true fully expanded code, but
will show up in the result of local-expand with an empty stop list.
(I've talked to mflatt about this and he said there isn't a way to get
true fully expanded code.)

Jay

On Mon, Mar 24, 2008 at 7:15 PM, Sam TH <samth at ccs.neu.edu> wrote:
> On Mon, Mar 24, 2008 at 8:42 PM, Jay McCarthy <jay.mccarthy at gmail.com> wrote:
>  > Look at collects/web-server/lang/freevars.ss for a (syntax -> (listof
>  >  identifier-syntax)) function
>
>  There's also an implementation (intended for use in other libraries)
>  in syntax/free-vars (maybe the webserver should use that?).
>
>  sam th
>
>
>
>  >
>  >  (Only works on expanded code)
>  >
>  >  Jay
>  >
>  >
>  >
>  >  On Mon, Mar 24, 2008 at 5:55 PM, YC <yinso.chen at gmail.com> wrote:
>  >  > Hi all -
>  >  >
>  >  > What's the best approach to determine free variables at source level?
>  >  >
>  >  > What i am trying to accomplish is to take a scheme expression from a file,
>  >  > say
>  >  >
>  >  > (+ foo bar)
>  >  >
>  >  > and transform
>  >  >
>  >  > (lambda (foo bar)
>  >  >   (+ foo bar))
>  >  >
>  >  > for arbitrary scheme expressions.
>  >  >
>  >  > Are there procedures that would allow me to determine whether a symbol has a
>  >  > binding?  Given scheme identifier can be bound to different values, it seems
>  >  > like this would require some sort of runtime environment inspection - is
>  >  > that true?
>  >  >
>  >  > Thanks,
>  >  > yc
>  >  >
>  >  >
>  >
>  > > _________________________________________________
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>  >  >
>  >  >
>  >
>  >
>  >
>  >  --
>  >  Jay McCarthy <jay.mccarthy at gmail.com>
>  >  http://jay.teammccarthy.org
>  >
>  >
>  > _________________________________________________
>  >   For list-related administrative tasks:
>  >   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>  >
>
>
>
>  --
>  sam th
>  samth at ccs.neu.edu
>



-- 
Jay McCarthy <jay.mccarthy at gmail.com>
http://jay.teammccarthy.org