Data commit

Task/Averages-Simple-moving-average/Fantom/averages-simple-moving-average.fantom

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+class MovingAverage
+{
+  Int period
+  Int[] stream
+
+  new make (Int period)
+  {
+    this.period = period
+    stream = [,]
+  }
+
+  // add number to end of stream and remove numbers from start if
+  // stream is larger than period
+  public Void addNumber (Int number)
+  {
+    stream.add (number)
+    while (stream.size > period)
+    {
+      stream.removeAt (0)
+    }
+  }
+
+  // compute average of numbers in stream
+  public Float average ()
+  {
+    if (stream.isEmpty)
+      return 0.0f
+    else
+      1.0f * (Int)(stream.reduce(0, |a,b| { (Int) a + b })) / stream.size
+  }
+}
+
+class Main
+{
+  public static Void main ()
+  { // test by adding random numbers and printing average after each number
+    av := MovingAverage (5)
+
+    10.times |i|
+    {
+      echo ("After $i numbers list is ${av.stream} average is ${av.average}")
+      av.addNumber (Int.random(0..100))
+    }
+  }
+}