8 hours ago, Carl Eastlund wrote:
> I'm confused about so-called "identifier macros". I had thought
> that ordinary transformers bound to functions could only transform
> application-position references to themselves, and that a "set!
> transformer" was required to transform bare references and set!
> references. Turns out I was wrong, set! transformers are in fact
> only required to transform set! references. So why are they listed
> under the documentation for "identifier macros" and why does that
> documentation imply that normal transformers can't handle bare
> references?
Not an answer, but something that I always thought would be useful is
to expand the target in a `set!' expression. I implemented this in
swindle, so you can do this:
-> (define b (box 1))
-> (defsubst v (unbox b))
-> v
1
-> (set! v 10)
-> (inc! v)
-> v
11
-> b
#&11
(`defsubst' is somewhat similar to an extended version of
`define-syntax-rule', and `inc!' is the obvious macro that is possible
with generalized CL-style setters.)
--
((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay:
http://barzilay.org/ Maze is Life!
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