+(defun fast-string-search (substr str substr-length startpos endpos)
+ (declare (simple-string substr str)
+ (fixnum substr-length startpos endpos)
+ (optimize (speed 3) (space 0) (safety 0)))
+ (do* ((pos startpos (1+ pos))
+ (lastpos (- endpos substr-length)))
+ ((> pos lastpos) nil)
+ (declare (fixnum pos lastpos))
+ (do ((i 0 (1+ i)))
+ ((= i substr-length)
+ (return-from fast-string-search pos))
+ (declare (fixnum i))
+ (unless (char= (schar str (+ i pos)) (schar substr i))
+ (return nil)))))
+