Data update

Task/Forward-difference/FutureBasic/forward-difference.basic

@@ -0,0 +1,26 @@
+include "NSLog.incl"
+
+CFArrayRef local fn ForwardDifference( arr as CFArrayRef )
+  CFMutableArrayRef result = fn MutableArrayNew
+  for NSUInteger i = 1 to len(arr) - 1
+    CFNumberRef diff = @(dblval(arr[i]) - dblval(arr[i-1]))
+    MutableArrayAddObject( result, diff )
+  next
+end fn = result
+
+CFArrayRef local fn NthForwardDifference( arr as CFArrayRef, n as NSInteger )
+  if ( len(arr) == 0 ) then return @[]
+  if ( n == 0 ) then return arr
+end fn = fn NthForwardDifference( fn ForwardDifference( arr ), n - 1 )
+
+void local fn DoIt
+  CFArrayRef initialArray = @[@90, @47, @58, @29, @22, @32, @55, @5, @55, @73]
+  for NSInteger i = 0 to 9
+    CFArrayRef diff = fn NthForwardDifference( initialArray, i )
+    NSLog(@"[%@]", fn ArrayComponentsJoinedByString( diff, @", " ))
+  next
+end fn
+
+fn DoIt
+
+HandleEvents