Initial data commit

Task/Factorial/Janet/factorial-1.janet

@@ -0,0 +1,5 @@
+(defn factorial [x]
+    (cond
+        (< x 0) nil
+        (= x 0) 1
+        (* x (factorial (dec x)))))

Task/Factorial/Janet/factorial-2.janet

@@ -0,0 +1,7 @@
+(defn factorial-iter [product counter max-count]
+  (if (> counter max-count)
+    product
+    (factorial-iter (* counter product) (inc counter) max-count)))
+
+(defn factorial [n]
+  (factorial-iter 1 1 n))

Task/Factorial/Janet/factorial-3.janet

@@ -0,0 +1,9 @@
+(defn factorial [x]
+    (cond
+        (< x 0) nil
+        (= x 0) 1
+        (do
+            (var fac 1)
+            (for i 1 (inc x)
+                (*= fac i))
+            fac)))

Task/Factorial/Janet/factorial-4.janet

@@ -0,0 +1,5 @@
+(defn factorial [x]
+    (cond
+        (< x 0) nil
+        (= x 0) 1
+        (product (range 1 (inc x)))))