Add symmetricDifference to ImmutableResourceSet

RIPE-NCC · Nov 28, 2022 · 81b98cd · 81b98cd
1 parent 98a3845
commit 81b98cd
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diff --git a/src/main/java/net/ripe/ipresource/ImmutableResourceSet.java b/src/main/java/net/ripe/ipresource/ImmutableResourceSet.java
@@ -195,6 +195,14 @@ public ImmutableResourceSet minus(ImmutableResourceSet that) {
         }
     }
 
+    /**
+     * @return $this \Delta that$
+     */
+    public ImmutableResourceSet symmetricDifference(ImmutableResourceSet that) {
+        // $this \Delta that = (this \setminus that) \cup (that \setminus this)$
+        return (this.minus(that)).union((that.minus(this)));
+    }
+
     public ImmutableResourceSet complement() {
         return universal().difference(this);
     }

diff --git a/src/test/java/net/ripe/ipresource/ImmutableResourceSetTest.java b/src/test/java/net/ripe/ipresource/ImmutableResourceSetTest.java
@@ -206,6 +206,14 @@ public void test_minus() {
         assertEquals(ImmutableResourceSet.parse("AS3333-AS3334, AS3336-AS4444, 10.0.0.0-10.4.255.255, 10.6.0.0-10.255.255.255"), difference);
     }
 
+    @Test
+    public void test_symmetricDifference() {
+        ImmutableResourceSet a = ImmutableResourceSet.parse("AS64512-AS64513");
+        ImmutableResourceSet b = ImmutableResourceSet.parse("AS64513-AS64514");
+        ImmutableResourceSet symDiff = a.symmetricDifference(b);
+        assertEquals(ImmutableResourceSet.parse("AS64512, AS64514"), symDiff);
+    }
+
     @Test
     public void test_intersection() {
         ImmutableResourceSet empty = ImmutableResourceSet.parse("");