[racket] Bindings' differences between 5.2.1 and 5.3

From: Gustavo Massaccesi (gustavo at oma.org.ar)
Date: Wed Aug 8 16:32:52 EDT 2012


I'm upgrading from version 5.2.1 to version 5.3 and I found a problem.

The idea is that the module "auto-req-lang.rkt" is like racket/base,
but when it is used as a language, it is automatically required
for-syntax. (The name is extracted automatically.) The original file
is much longer, but this is a minimal example that shows the
difference between the Racket versions.

In this case, the following "example.rkt" program works in 5.2.1 but
fails in 5.3

; version 5.2.1 ==> #f

; version 5.3   ==> Error: syntax: unbound identifier in the
transformer environment;
 also, no #%app syntax transformer is bound in: syntax


;=== file:  "auto-req-lang.rkt"
#lang racket/base
(require (for-syntax racket/base))
(provide (except-out (all-from-out racket/base) #%module-begin))
(provide (rename-out (module-begin #%module-begin)))

{define-syntax (module-begin stx)
  (syntax-case stx ()
    [(module-begin body ...)
     (let-values ([(me-name ??) (module-path-index-split (car
(identifier-binding #'module-begin)))])
       (with-syntax ([module-id (syntax-local-introduce #`#,me-name)])
            (require (for-syntax module-id))
            body ...

;=== end file:  "auto-req-lang.rkt"

;=== file:  "example.rkt"
#lang s-exp "auto-req-lang.rkt"

{define-syntax (just#f stx)
  (syntax #f)}

(display (just#f))

;=== file:  "example.rkt"

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