Add functions and lists

tests/fibonacci.ppl

@@ -0,0 +1,11 @@
+(let fib (function int [int y function fib]
+    (let retval 0)
+    (if (== 1 y) (set retval 0))
+    (if (== 2 y) (set retval 1))
+    (if (> y 2) 
+        (set retval (+ (fib (- y 1) fib) (fib (- y 2) fib)))
+    )
+    (return retval)
+))
+
+(print (fib 30 fib))

tests/functions.ppl

@@ -0,0 +1,6 @@
+(let x (function int [function in int num]
+    (print "recursively called" (+ num 1) "times") 
+    (in in (+ num 1))
+))
+
+(x x 1)