(import (chicken type))

(define-syntax define-type-pattern
  (syntax-rules ()
    ((define-type-pattern (type-name pattern ...) type-expression)
     (define-syntax type-name
       (syntax-rules ()
         ((type-name pattern ...)
          type-expression))))))

(define-type-pattern (alist-type key-type value-type) (list-of (pair key-type value-type)))

(let ((some-alist (the (alist-type symbol number) '())))
  (print some-alist))