compfuck.carp

(defndynamic search-matching-bracket [s m]
  (if (or (= (String.length s) 0) (= m 0))
    0
    (let [f (String.char-at s 0)]
      (inc (search-matching-bracket (String.tail s) (if (= \] f) (dec m) (if (= \[ f) (inc m) m)))))))

(defndynamic compile-compf-char [c s i]
  (case f
    \+ (list 1 '(Array.aupdate! &t h &(fn [x] (mod (Int.inc @x) 255))))
    \- (list 1 '(Array.aupdate! &t h &(fn [x] (max 0 (Int.dec @x)))))
    \> (list 1 '(set! h (+ h 1)))
    \< (list 1 '(set! h (- h 1)))
    \. (list 1 '(IO.print &(str (Char.from-int (copy (Array.unsafe-nth &t h))))))
    \, (list 1 '(Array.aset! &t h (Char.to-int (IO.get-char))))
    \[
      (let [end (search-matching-bracket (String.suffix s (+ i 1)) 1)]
        (list (+ end 1)
          `(while (/= &0 (Array.unsafe-nth &t h))
            (do
              %@(let [subs (String.slice s (+ i 1) end)]
                  (compile-compf subs 0))))))
    '(1 ())))

(defndynamic compile-compf [p i]
  (if (= i (String.length p))
    '()
    (let [f (String.char-at p i)]
      (if (= \] f)
        '()
        (let [incr-c (compile-compf-char f p i)]
          (let [incr (car incr-c)
                compiled (cadr incr-c)]
            (cons compiled
                  (compile-compf p
                                 (+ i incr)))))))))

(defmacro compf [prog]
  (eval
    `(defn main []
      (let-do [t (Array.replicate 30000 &0)
               h 0]
        %@(compile-compf prog 0)))))