0.question-about-scheme-macro.scm

; How do I implement the following macro in R5RS?
;
; (define! x)
; ==> (define x "x")
;     (define x "x!")

(define-syntax define!
  (syntax-rules ()
    [(_ name)
     (define name (symbol->string 'name))
     (define ... ...)]))

1.answer.scm

; In Gauche.
; But it's ugly.  Isn't there smarter solution?

(define-syntax define!
  (syntax-rules ()
    [(_ name)
     (let1 name!s (string-append (symbol->string 'name) "!")
       (map (cut eval <> (current-module))
            `((define ,(string->symbol name!s) ,name!s)
              (define name (symbol->string 'name)))))]))