I'm working through "Let's Build a Hygienic Macro Expander!", which is
great, but I'm confused about nested quote-syntax:
#lang racket
(require (for-syntax racket))
(define x 5)
(begin-for-syntax
(define-syntax m2
(lambda (stx)
#'#'x)))
;(let ()
(define-syntax m
(lambda (stx)
#`(let ((x 6))
#,(m2))))
(m)
;)
I think the x inside #'#'x should keep its original lexical context (prints
5). But maybe quote-syntax only keeps one layer of context, so the inside
#'x gets the context where m2 was called (prints 6)?
In DrRacket 6.9, I get 6 as shown, and uncommenting that extra let ()
changes it to output 5, which seems fishy. Other ways I can think of to
write it all return 6.
Can anyone enlighten me?
Thanks,
Dave
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