View difference between Paste ID: 3MQd79ej and vPBp2BKj

 (defmacro -> (init &rest funcs)
   (cond
     ((null funcs) `,init)
     ((eql 'if (car funcs)) `(-> (if ,init ,(cadr funcs) ,(caddr funcs)) ,@(cdddr funcs)))
     ((consp (car funcs))
      (let* ((gensym (gensym))
             (func (recursive-replace '_ `,gensym (car funcs))))
        `(let ((,gensym ,init)) (-> ,func ,@(cdr funcs)))))
      (t `(-> (,(car funcs) ,init) ,@(cdr funcs)))))
 
 (defun recursive-replace (item replace form)
   (loop for form in form collect
        (if (consp form)
            (recursive-replace item replace form)
            (if (eql form item)
                replace
                form))))
 
 
 (labels ((square (x) (* x x)))
    (-> 2 square sqrt))
 
 -> 2.0
 
 (-> 2 (* _ _) (sqrt _))
 
 -> 2.0
 
 ;; signum returns the sign of the given number
 (-> -3 signum plusp (if _ (print "true")
                           (print "false")))
 
 -> false
 
 (-> 3 signum plusp (if _ (print "true")
                          (print "false")))
--> true
+
 -> true
 
 
 ;; I also just added support for a more forth-style conditional
 
 (-> 3 signum plusp if (print "true") (print "false"))
 
 -> "true"
 
 (-> -3 signum plusp if (print "true") (print "false"))
 
 -> "false"