I’m working through the examples in Mythical Macros and am completely stumped on result6.
The goal is to replace the ???-pattern and ???-template in the following snippet in order to make it evaluate to true.
(define result6
(with-syntax
([???-pattern (syntax ((a (1 "alpha") (2 "beta"))
(b (3 "gamma") (4 "delta"))))])
(syntax ???-template)))
(equal? (syntax->datum result6)
'((a b) (1 2 3 4) ("alpha" "beta" "gamma" "delta")))
I think I’ve got the pattern correct but am lost for how to do the template and probably splicing. My best iteration:
(define result6
(with-syntax
([ ((l (n text) ...) ...)
#'((a (1 "alpha") (2 "beta"))
(b (3 "gamma") (4 "delta")))])
#'( (l ...) (~@ n ...) ... ) ))
This yields:
`((a b) 1 2 3 4)
I’ve not gotten the text template to work with anything I try. How do you solve this? What am I missing about this?
Got it!
I made the pattern to parse more explicit and then fiddled my way through the template.
(define syntax-example
#'((a (1 "alpha") (2 "beta")) (b (3 "gamma") (4 "delta"))))
(define result6
(with-syntax
([ ( (l (n1 t1) (n2 t2)) ...) syntax-example])
#'( (l ...) ((~@ n1 n2) ...) ((~@ t1 t2) ... ))))