Am Do., 27. Aug. 2020 um 04:14 Uhr schrieb Alex Shinn <xxxxxx@gmail.com>:

>> Sorry, I didn't mean that it was difficult, least of all for you. Just
>> tedious and error-prone. My point about the relative inadequacy of
>> syntax-rules as is was: An addition of some local things (like
>> match-letrec) shouldn't lead to a global rewrite.
>
>
> You can write brittle and short-sighted code with any framework,
> I wouldn't draw too many conclusions from that.  I can imagine
> ways to write this more cleanly with syntax-rules.
>
> I'm not arguing syntax-rules is the best macro system by any
> means.  But there are two reasons to prefer a SRFI which
> at least _can_ be implemented in pure syntax-rules.  Firstly,
> because syntax-rules is the lowest common denominator.
> Secondly because, in the same spirit of the "lambda the ultimate"
> papers where we stretched how much could be done with just
> lambda as a primitive, it is interesting to see how much can be
> done with a simple macro system.  Doubtless there are better
> axioms than syntax-rules, but most efforts are in more complex,
> rather than simpler, systems.

I have thought again about my statement about the relative (!)
inadequacy of syntax-rules to maintain large macro code bases.

This had led me to the belief that my analysis of that aspect of
syntax-rules wasn't well-reasoned. While programming with syntax-rules
has its share of inconveniences (like the need for manual translation
into CPS style), I was arguing with a local-global dependence. While
it may be true that the CPS-style of syntax-rules programming
exacerbates the problem, it is by no means defining for syntax-rules.

Also in ordinary Scheme programming, we may have to globally refactor
programs when an inner-most procedure suddenly needs a value
previously only available at the outer-most level. The Scheme answer
to mitigating this problem is parameter objects. And so are syntax
parameters on the macro side. But syntax parameters are completely
orthogonal to the macro system used. And syntax parameters +
syntax-rules still has all the nice properties of syntax-rules
compared with more general macro systems about which fewer things can
be proven.