[racket] Macro in typed racket

Will this help: 

#lang typed/racket

(define-syntax (the stx)
  (syntax-case stx ()
    [(_ (define (f x) e))
     (let ((capital-x (capitalize stx #'x)))
       #`(begin 
         (: f (-> #,capital-x #,capital-x))
         (define (f x)
           e)))]))

(define-for-syntax (capitalize stx x)
  (define x:str (symbol->string (syntax-e x)))
  (datum->syntax stx (string->symbol (string-titlecase x:str))))

(define-type X Integer)

(the 
 (define (f x)
   x))

(f 10)

(f 'a) ;; <-- type check fails, comment out 





On Oct 7, 2014, at 2:38 PM, Jack Firth <jackhfirth at gmail.com> wrote:

> I read a tweet about someone wistfully wishing there was some sort of "the" operator in a typed non-parensy language such that one could write something like this:
> 
>     Customer someFunc(the customer) { ... }
> 
> and have it mean:
> 
>     Customer someFunc(Customer customer) { ... }
> 
> Basically, an operator to take care of the common case where the variable name is just the lower-camel-case form of the type. As a Racket fan, I wanted to see if I could do this with a macro in Typed Racket. After some mucking around I had a form that handled the syntax correctly, but I couldn't use it in typed racket because the type checker and type annotations run as macros *before* my macro expands. As I read further, it seems to be the case that macros in typed racket are a very thorny problem and an area of open research. So is it currently possible to implement a "the" operator like the one shown above in typed racket? And if so, how would it be done?
> ____________________
>  Racket Users list:
>  http://lists.racket-lang.org/users