[plt-scheme] string-eval

I added the comment to StructuresReadingAndWriting, but note that "the
Scheme Cookbook folks" can mean you too.  There is no membership fee
and nobody will haze you (I think). :-)

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Daniel

On Wed, 23 Mar 2005 23:58:14 +0000, djneu at att.net <djneu at att.net> wrote:
>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> 
> Robby, Jens,
> 
> Many thanks - using ~s did it!
> 
> Any thoughts for the Scheme Cookbook folks on whether it's worth
> putting a note in one of the recipes Jens referenced or maybe
> creating a new one?
> 
> Cheers,
> David
> 
>  -------------- Original message ----------------------
> From: Robby Findler <robby at cs.uchicago.edu>
> > You need to use
> >
> >   ~s
> >
> > not ~a.
> >
> > If you look closely at the first case, you'll see that you're getting
> > back a symbol, not a string. ~s means to use `write' and ~a means to
> > use display.
> >
> > Robby
> >
> > At Wed, 23 Mar 2005 17:50:24 -0500, "David J. Neu" wrote:
> > >   For list-related administrative tasks:
> > >   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> > >
> > > Hi,
> > >
> > > I'd like to be able to store an association list in a DBMS and later
> > > retrieve it.
> > >
> > > The code below works fine for
> > > (define alist `((a . 1) (b . "foo")))
> > >
> > > but generates the error:
> > >
> > > UNKNOWN::26: read: unexpected ')'
> > >
> > > when b is "", i.e. for
> > > (define alist `((a . 1) (b . "")))
> > >
> > > Many thanks for any suggestions!
> > >
> > > Cheers,
> > > David
> > >
> > >
> > >
> > > (require (lib "string.ss")
> > >      (lib "pconvert.ss"))
> > >
> > > (define alist `((a . 1) (b . "")))
> > >
> > > ;; simulate storing alist in a DBMS and reading it back
> > > (define alist-as-string (format "~a" (print-convert alist)))
> > >
> > > (eval-string alist-as-string)
> > >
> > > UNKNOWN::26: read: unexpected ')'
> 
>