add exp function

1 files changed, 19 insertions, 5 deletions

diff --git a/stdlib/math.nxs b/stdlib/math.nxs
index f913d82..77ffc7f 100644
--- a/stdlib/math.nxs
+++ b/stdlib/math.nxs
@@ -3,18 +3,32 @@
 (bind powi (lambda (x y)
 	(if (= y 1)
 	x
-	(* x (pow x (- y 1)))
-)))
+	(* x (powi x (- y 1)))
+	)
+))
+
+(bind inv (lambda (x) (/ 1.0 x)))
+
 (bind factorial (lambda (n)
-        (if (= n 0) 1 (* n (factorial (print(- n 1)))))))
+        (if (= n 0) 1 (* n (factorial (- n 1))))))
 
 ;; complicated functions
-(bind exp (lambda (x) x))
+(bind expr (lambda (x y)
+	(if (<= y 0)
+	1
+	(+ (/ (powi x y) (factorial y)) (expr x (- y 1)))
+	)
+))
 
-(bind ln (lambda (x) x))
+(bind exp (lambda (x)
+	(expr x 13)
+))
 
 (bind sin (lambda (x) x))
 
 (bind cos (lambda (x) x))
 
 (bind tan (lambda (x) (/ (sin x) (cos x))))
+
+(print (exp 1.0))
+;(print (ln (exp 1)))