scm.mes: add expt.

scm.mes

@@ -185,6 +185,11 @@
 (define (remainder x y)
   (- x (* (/ x y) y)))
 
+(define (expt x y)
+  (let loop ((s 1) (count y))
+    (if (= 0 count) s
+        (loop (* s x) (- count 1)))))
+
 (define (max x . rest)
   (if (null? rest) x
       (let* ((y (car rest))

test.mes

@@ -104,6 +104,7 @@
 (pass-if "/" (seq? (/ 9 3) 3))
 (pass-if "remainder" (seq? (remainder 11 3) 2))
 (pass-if "modulo" (seq? (modulo 11 3) 2))
+(pass-if "expt" (seq? (expt 2 3) 8))
 
 (pass-if "=" (seq? 3 '3))
 (pass-if "= 2" (not (= 3 '4)))