(defvar *debug* t)

(defun my-abs (x)
	(if (< x 0) (- 0 x) x))

(defun my-try-sqrt-guess (g x &optional (last nil))
	(let* (
			(x/g (float (/ x g)))
			(avg (float (/ (+ g x/g) 2)))
			(result (- x (* avg avg)))
		)
		(if *debug* (progn (fastcgi:out "(calc X: " x ", G: " g ", X/G: " x/g ", Avg: " avg ", Result: " result ")" #\newline)) nil)
		(if (or (and (not (eq last nil)) (equal last result)) (< (my-abs result) 0.000001)) avg (my-try-sqrt-guess avg x result))
	))

(defun my-sqrt (x)
	(my-try-sqrt-guess 1 x))

(fastcgi:out "Content-type: text/plain" #\newline #\newline)
(let ((x (if (not (equal "" (fastcgi:getenv "QUERY_STRING"))) (parse-integer (fastcgi:getenv "QUERY_STRING") :radix 10) 2)))
	(fastcgi:out
		"Note: Will accept a query string parameter being a number to sqrt e.g. http://lisptests.phillipstreet.com/demo_sqrt.lisp?100" #\newline
		"System Sqrt of " x " is " (sqrt x) #\newline)
	(let ((root (my-sqrt x)))
		(fastcgi:out
			"My Sqrt of " x " is " (if (= (setf a (round root)) (float root)) (setf a (round root)) (float root)) #\newline)))