[plt-scheme] Example from "The Scheme Programming Language" fails

> The last example in chapter 8 of "TSPL" is a define-structure
> macro that has an effect similar to define-struct. I was going
> to use that example as a template and have it's backend be
> make-struct-type.
>
> If I copy and paste the example into DrScheme with the MzScheme
> language, and evaluate:
>
> 	(define-structure foo a b c)
>
> I get an error. (I won't include the error here since it really
> only makes sense when when shown the the DrScheme REPL).
>
> Any ideas on how to modify that example so that it works? Or,
> should it work as given?

Reacting purely to the nature of the error message, I tried wrapping the
four occurences of 'syntax' that are used in a list context, with a call to
syntax->list.  This seems to fix the example.  Don't assume that this is a
perfectly correct answer, though - I haven't tried to understand the
example, and I don't know much about the syntax functions.

The changed chunk of code is all contained in the following six contiguous
lines:

        (syntax->list (syntax (field ...)))))
  ((assign ...)
   (map (lambda (x) (gen-id x "set-" (syntax name) "-" x "!"))
        (syntax->list (syntax (field ...)))))
  (structure-length (+ (length (syntax->list (syntax (field ...)))) 1))
  ((index ...) (let f ((i 1) (ids (syntax->list (syntax (field ...)))))


> (I won't include the error here since it really only
> makes sense when when shown the the DrScheme REPL).

Don't let DrScheme's cool graphical wizardry throw you off: the plain text
of the error was enough to diagnose the problem - it read: "map: expects
type <list> as 2nd argument, given: #<syntax:21:17>".  The highlighted code
showed a call to map in which the 2nd argument - which should be a list -
was actually a call to 'syntax', which (apparently) does not result in a
list.  That's all I based the above fix on.

Anton