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 [email protected]. 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
