anchor.diff:  	   (focus)
   	   (keydown (lambda (evt)
   		      (when (contains? evt.key-code (list 13 9))
  -			(defvar prev-value (chain textarea (val)))
  -			(defvar tab "  ")
  -			(defvar cursor-position
  -			  (send textarea attr 'selection-start))
  +			(defvar prev-value (chain textarea (val))
  +                          tab "  "
  +                          cursor-position (send textarea attr 'selection-start))
  +
   			(when (<= prev-value.length cursor-position)
   			  (defvar tab
   			    (repeat (determine-tab-stop prev-value) " "))
  
positive.code: 			  (send textarea val (concat prev-value tab)))
  			false)))
  	   (keyup (lambda (evt)
  		    (try (chain (jq "#output")
  				(text (sibilant.translate-all
  				       (send textarea val)))
  				(remove-class 'error))
  			 (chain (jq "#output")
  				(text e.stack)
  				(add-class 'error))))))
      (check-hash)))
  
negative.code:     	      (chain items (first) (attr 'id))))
  
      (defun calculate-height ()
  	(chain ($ "textarea, #output")
  	       (each (lambda (&rest args)
  		       (defvar block ($ this)
                                 value (+ (send block val)
  					(send block text))
                                 lines (length
  				      (or (list)
  					  (send value match /[^\s]\n/g))))
  		       (block.height (* (+ 1 lines) 20))))))
  
      (defvar textarea ($ 'textarea))
  
      (defun determine-tab-stop (value)
        (defvar lines       (send value split "\n")
                open-parens (list))
        (each (line) lines
  	  (each (char offset) (line.split "")
                  (switch char
                          ("(" (open-parens.push offset))
                          (")" (open-parens.pop)))))
        (+ 2 (last open-parens)))
  
      (defun repeat (times string)
  