View difference between Paste ID: Tq0x0QXV and 2N51sRLP

 ;=============================================================================
 ;  Pratt's Top Down Operator Precedence Parser
 ;=============================================================================
 (def make-assoc (f)
   (fn (bind pre inf)
     (list bind (and pre (fn ()    (pre     (f bind))))
                (and inf (fn (val) (inf val (f bind)))))))
 
 (= left  (make-assoc (fn (bind) (expression bind))))
 (= right (make-assoc (fn (bind) (expression (- bind 1)))))
 
 (def literal (x)
   (list 0 (fn () x) nil))
 
 (def expression (bind)
   (withs (x    (car tokens)
           nud  (aand x (x 1) (it)))
     (zap cdr tokens)
     (while (and x (< bind (x 0)))
       (when (= x car.tokens)
         (zap cdr tokens)
         (zap (x 2) nud)))
     nud))
 
 (mac infix (n parms . body)
   `(left ,n nil (fn ,parms ,@body)))
 
 (mac prefix (n parms . body)
   `(left ,n (fn ,parms ,@body) nil))
 
 
 ;=============================================================================
 ;  ssexpand
 ;=============================================================================
 (= ssyntax-rules* (obj #\~ (prefix 10 (r)  `(complement ,r))
                        #\: (infix 10 (l r) `(compose ,l ,r))
                        #\& (infix 10 (l r) `(andf ,l ,r))
                        #\. (infix 10 (l r) `(,l ,r))
                        #\! (infix 10 (l r) `(,l ',r))))
 
 (def chars->value (x)
   (literal:read:string:rev x))
 
 (def tokenize (x)
   ((afn (x l r)
      (aif (no x)
             (rev:cons chars->value.l r)
           (ssyntax-rules* car.x)
             (self cdr.x nil (cons it (cons chars->value.l r)))
           (self cdr.x (cons car.x l) r)))
    (coerce string.x 'cons) nil nil))
 
 (def ssexpand (x)
   (= tokens tokenize.x)
   (expression -1))