A-M baby

Task/Generator-Exponential/Fantom/generator-exponential.fantom

@@ -0,0 +1,40 @@
+class Main
+{
+  // Create and return a function which generates mth powers when called
+  |->Int| make_generator (Int m)
+  {
+    current := 0
+    return |->Int|
+    {
+      current += 1
+      return (current-1).pow (m)
+    }
+  }
+
+  |->Int| squares_without_cubes ()
+  {
+    squares := make_generator (2)
+    cubes := make_generator (3)
+    c := cubes.call
+    return |->Int|
+    {
+      while (true)
+      {
+        s := squares.call
+        while (c < s) { c = cubes.call }
+        if (c != s) return s
+      }
+      return 0
+    }
+  }
+
+  Void main ()
+  {
+    swc := squares_without_cubes ()
+    20.times { swc.call } // drop 20 values
+    10.times // display the next 10
+    {
+      echo (swc.call)
+    }
+  }
+}