Re: Lexical references in DEFMACRO

[David A. Moon <Moon@SCRC-STONY-BROOK.ARPA>]

    Date: 5 May 86 15:25 PDT
    From: Gregor.pa@Xerox.COM

    Another problem with having the lexical environment of a defmacro'd
    macro be the null environment is that you can't "macroize for speed" the
    following perfecly reasonable coding style:
 
    (let ((unique-id "foo"))
      (defun make-foo () (list unique-id () () ()))

      (defun foo-p (x) (and (listp x) (eq (car x) unique-id))))

    Specifically, you couldn't turn the defun of foo-p into the seemingly
    obvious defmacro.

I think if you actually write out the seemingly obvious defmacro, you
will see that it's not so:

      (defmacro foo-p (x) `(and (listp ,x) (eq (car ,x) unique-id))))

which does not reference unique-id as a variable from the body of
the macro, only from the expansion of the macro.

Of course the inline proclamation was made to order for this.  I wonder
if it was intended to work for things not at top level.  This can of
worms should not be dealt with piecemeal.