Another solution: #lang racket (define-syntax (def-both-phases stx) (syntax-case stx () ((_ rest ...) #'(begin (define rest ...) (define-for-syntax rest ...))))) (def-both-phases (my-function x) (+ x 1)) (define-syntax my-macro (lambda (stx) (datum->syntax stx (my-function (cadr (syntax->datum stx)))))) (my-macro 5) (my-function 7) Jos From: Yushuo Xiao I am using syntax transformers to define macros in Racket. I want to create some helper functions to help me manipulate the syntax. However, the functions I defined outside the syntax transformer are not available inside the syntax transformer. For example, in the following code (define (my-function x) (+ x 1)) (define-syntax my-macro (lambda (stx) (datum->syntax stx (my-function (cadr (syntax->datum stx)))))) I got the error "my-function: reference to an unbound identifier at phase: 1; the transformer environment". After some searching, I am able to write the following code so that `my-function` is available inside the syntax transformer. (begin-for-syntax (define (my-function x) (+ x 1))) (provide (for-syntax my-function)) (define-syntax my-macro (lambda (stx) (datum->syntax stx (my-function (cadr (syntax->datum stx)))))) But the problem is, `my-function` is not available outside the syntax transformer this time. Sometimes I want to check those helper functions in ordinary code, so I need to be able to call it from both inside and outside the syntax transformer, just like the function `cadr`. How can I achieve that? I know my question has something to do with Racket's syntax model, in particular the concept of "phase level", but I never really understand it. If you could provide some easy-to-follow tutorials explaining it I would even be more grateful. (Also, I have asked the same question on StackOverflow before I am aware of this Google group. Is this place more suitable for asking Racket questions like this than StackOverflow? Should I delete the question on StackOverflow?) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/ADFCA8F8-72A0-4F1F-89B1-CE28BBEF4017%40hxcore.ol. |
- [racket-users] How to define a function that can be used both ... Yushuo Xiao
- RE: [racket-users] How to define a function that can be u... Jacob Jozef
- RE: [racket-users] How to define a function that can be u... Jacob Jozef
