baklengs.rkt

#lang racket
(provide (rename-out [my-read read]
                     [my-read-syntax read-syntax]))

(define (my-read in) (syntax->datum (my-read-syntax #f in)))

(define (rev stx)
  (define l (syntax->list stx))
  (if l
      (datum->syntax stx (reverse (map rev l)) stx stx)
      stx))

(define (my-read-syntax src in)
  (define blah #'e)
  (define res
    (let loop ()
      (define stx (read-syntax src in))
      (cond [(eof-object? stx) '()]
            [else
             (set! blah stx)
             (cons (rev stx) (loop))])))
  (datum->syntax blah
                 `(module merp racket
                    ,@res)
                 blah
                 blah))

test.rkt

#lang reader "baklengs.rkt"

((x x +)
 (x double) define)

((3 2 1 list) double map)

Put both files in same dir, e.g. by downloading zip and unzipping somewhere. Run test.rkt with Racket. Should get the list '(2 4 6).