#lang racket
(require "semantics.rkt")
(provide greater-than
         less-than
         plus
         minus
         period
         comma
         colon
         brackets
         (rename-out [my-module-begin #%module-begin]))

;; The current-state is a parameter used by the
;; rest of this language.
(define current-state (make-parameter (new-state)))

;; Every module in this language will make sure that it
;; uses a fresh state.
(define-syntax-rule (my-module-begin body ...)
  (#%plain-module-begin
    (parameterize ([current-state (new-state)])
body ...)))

(define-syntax-rule (greater-than)
  (increment-ptr (current-state)))

(define-syntax-rule (less-than)
  (decrement-ptr (current-state)))

(define-syntax-rule (plus)
  (increment-byte (current-state)))

(define-syntax-rule (minus)
  (decrement-byte (current-state)))

(define-syntax-rule (period)
  (write-byte-to-stdout (current-state)))

(define-syntax-rule (comma)
  (read-byte-from-stdin (current-state)))

(define-syntax-rule (colon)
  (write-number-to-stdout (current-state)))

(define-syntax-rule (brackets body ...)
  (loop (current-state) body ...))

#|
(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)
(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)
(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)
(period)(minus)(minus)(minus)(period)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(period)(period)(plus)(plus)(plus)(period)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)
(minus)(plus)(plus)(plus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)
(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)
(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(plus)(plus)(plus)(plus)(plus)(plus)
(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(plus)(period)
(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)
(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)(comma)(period)(brackets(comma)(period))
|#

#|
;Hello World!
(plus)(plus)(plus)(plus)(plus) (plus)(plus)(plus)(plus)(plus)
(brackets
 (greater-than) (plus)(plus)(plus)(plus)(plus) (plus)(plus)
 (greater-than) (plus)(plus)(plus)(plus)(plus) (plus)(plus)
 (plus)(plus)(plus) (greater-than) (plus)(plus)(plus)
 (greater-than) (plus) (less-than)(less-than)(less-than)
 (less-than) (minus))
(greater-than) (plus)(plus) (period)
(greater-than) (plus) (period)
(plus)(plus)(plus)(plus)(plus) (plus)(plus) (period)
(period) (plus)(plus)(plus) (period)
(greater-than) (plus)(plus) (period)
(less-than)(less-than) (plus)(plus)(plus)(plus)(plus)
(plus)(plus)(plus)(plus)(plus) (plus)(plus)(plus)(plus)(plus)
(period) (greater-than) (period)
(plus)(plus)(plus) (period)
(minus)(minus)(minus)(minus)(minus)(minus)(period)
(minus)(minus)(minus)(minus)(minus)(minus)(minus)(minus)
(period)(greater-than) (plus) (period) (greater-than) (period)
|#