gistfile1.sls

(define read-js
  (lambda (ch port src line col pos)
    (datum->syntax
     #f
     (->js (read port))
     (let-values ([(l c p) (port-next-location port)])
       (list src line col pos (and pos (- p pos)))))))

(define js-readtable
  (make-readtable #f #f 'non-terminating-macro read-js))

(define (test x)
  (parameterize ([current-readtable js-readtable])
    (read (open-input-string x))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

> > > > (test "(js:lambda (x y) (js:+ x y))")
UNKNOWN::15: read: unexpected `)'

 === context ===
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
/usr/local/lib/racket/collects/racket/private/misc.rkt:74:7

> (test "'(1 2 3)")
UNKNOWN::7: read: unexpected `)'

 === context ===
stdin::8017: read-js
stdin::8017: read-js
stdin::8017: read-js
/usr/local/lib/racket/collects/racket/private/misc.rkt:74:7

> (test "1")
#<eof>
> (test "1 2")
#<eof>
> (test "(1 2)")
UNKNOWN::4: read: unexpected `)'

 === context ===
stdin::8017: read-js
stdin::8017: read-js
/usr/local/lib/racket/collects/racket/private/misc.rkt:74:7

> (test "'(1 2)")
UNKNOWN::5: read: unexpected `)'

 === context ===
stdin::8017: read-js
stdin::8017: read-js
/usr/local/lib/racket/collects/racket/private/misc.rkt:74:7

>