Added Monoid.multiply()

orionll · orionll · commit 81daa763849a · 2015-06-12T14:23:14.000+06:00
diff --git a/core/src/main/java/fj/Monoid.java b/core/src/main/java/fj/Monoid.java
@@ -89,6 +89,18 @@ public A zero() {
     return zero;
   }
 
+  /**
+   * Returns a value summed <code>n</code> times (<code>a + a + ... + a</code>)
+   * @param n multiplier
+   * @param a the value to multiply
+   * @return <code>a</code> summed <code>n</code> times. If <code>n <= 0</code>, returns <code>zero()</code>
+   */
+  public A multiply(final int n, final A a) {
+    A m = zero();
+    for (int i = 0; i < n; i++) { m = sum(m, a); }
+    return m;
+  }
+
   /**
    * Sums the given values with right-fold.
    *
