Add NEL.minimum/maximum and safe versions of minimum/maximum for List

shimib · jbgi · commit 6ac5f9547dbb · 2017-01-23T20:22:20.000+01:00
* added minimum/maximum on NEL &amp;&amp; changed impl of minimumOption/maximumOption in List to use it

* spaces for tabs
diff --git a/core/src/main/java/fj/data/List.java b/core/src/main/java/fj/data/List.java
@@ -1465,6 +1465,16 @@ public final A maximum(final Ord<A> o) {
     return foldLeft1(o::max);
   }
 
+  /**
+   * Returns the maximum element in this list according to the given ordering.
+   *
+   * @param o An ordering for the elements of the list.
+   * @return The optional maximum element in this list according to the given ordering.
+   */
+  public final Option<A> maximumOption(final Ord<A> o) {
+    return NonEmptyList.fromList(this).map(nel -> nel.maximum(o));
+  }
+  
   /**
    * Returns the minimum element in this list according to the given ordering.
    *
@@ -1474,6 +1484,16 @@ public final A maximum(final Ord<A> o) {
   public final A minimum(final Ord<A> o) {
     return foldLeft1(o::min);
   }
+  
+  /**
+   * Returns the minimum element in this list according to the given ordering.
+   *
+   * @param o An ordering for the elements of the list.
+   * @return The optional minimum element in this list according to the given ordering.
+   */
+  public final Option<A> minimumOption(final Ord<A> o) {
+    return NonEmptyList.fromList(this).map(nel -> nel.minimum(o));
+  }
 
   public final java.util.List<A> toJavaList() {
     return new java.util.LinkedList<>(toCollection());
diff --git a/core/src/main/java/fj/data/NonEmptyList.java b/core/src/main/java/fj/data/NonEmptyList.java
@@ -226,6 +226,28 @@ public NonEmptyList<A> sort(final Ord<A> o) {
     return nel(list.head(), list.tail());
   }
 
+  
+  /**
+   * Returns the minimum element in this non empty list according to the given ordering.
+   *
+   * @param o An ordering for the elements of this non empty list.
+   * @return The minimum element in this list according to the given ordering.
+   */
+  public final A minimum(final Ord<A> o) {
+    return foldLeft1(o::min);
+  }
+  
+  /**
+   * Returns the maximum element in this non empty list according to the given ordering.
+   *
+   * @param o An ordering for the elements of this non empty list.
+   * @return The maximum element in this list according to the given ordering.
+   */
+  public final A maximum(final Ord<A> o) {
+    return foldLeft1(o::max);
+  }
+  
+  
   /**
    * Zips this non empty list with the given non empty list to produce a list of pairs. If this list and the given list
    * have different lengths, then the longer list is normalised so this function never fails.
