Re: problems with syntax-case and with-syntax

[Matt Wette <matt.wette@gmail.com>]

> On Aug 27, 2017, at 6:35 PM, Mark H Weaver <mhw@netris.org> wrote:
> 
> Mark H Weaver <mhw@netris.org> writes:
> 
>> The problem is that in Guile 2.2, whenever (define <id> ...) is found in
>> the expanded code, where <id> was introduced by a macro (i.e. not passed
>> as an explicit argument to the macro), Guile will rewrite the <id> into
>> a new name based on the hash of the entire definition form.
> 
> I forgot to mention that only top-level definitions are munged in this
> way.
> 
> Also, my parenthetical definition of what it means to be "introduced by
> a macro" lacked precision.  To avoid <id> being "introduced by a macro",
> it's not enough for <id> to have been passed an argument to the macro
> that generated the definition.  If that were the case, you could work
> around this by adding an additional layer of macros, where the upper
> layer generated <id> and passed it down to the lower layer which would
> generate the definition.
> 
> To avoid <id> being considered "introduced by a macro", <id> must
> ultimately occur verbatim in the source code outside of any macro
> template.

I have read through the posts, and the Guile 2.2 ref manual.  The explanations
are not quite complete in my mind.  If all top-level id's introduced by macros
were munged, then it would break a lot of existing code.  See, for example,
the `define-structure' example in "The Scheme Programming Language", 4th ed.
It seems identifiers introduced by datum->syntax are preserved, as long 
as they are not redefined.  Is that correct?

In my case, I was redefining by architecture (or convention). I was generating 
"wrap-" + <identifier> in a macro that called a another macro that made the same 
definition.  Is it bad form to assume an convention like this?

Off to do more reading on this: Dybvig's paper on syntax-case and I have the 
book too.  and R6RS ...

Matt