(defvar *forward-index* (make-hash-table))
(defvar *inverse-index* (make-hash-table))
(defvar *x* nil)

; index a site into *forward-index*
(defun index-site (html doc-id)
	(let ((words (split-sequence #\Space html))
	      (index (make-hash-table)))
	     (dolist (word words) (if (gethash word index)
				       (incf (gethash word index))
				       (setf (gethash word index) 0)))
(setf *x* index)
(setf (gethash doc-id *forward-index*) index)))


; generate the inverse index from *forward-index* into *inverse-index*
(defun generate-inverse-index ()
 (maphash (lambda (doc-id word-map)
	   (maphash (lambda (word hits)
		     (let ((doc-hit-list (list doc-id hits)))
		     (if (gethash word *inverse-index*)
			 (push doc-hit-list (gethash word *inverse-index*))
			 (setf (gethash word *inverse-index*) (list doc-hit-list))))) word-map)) *forward-index*))