1 files changed, 73 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/util/timeline/SingletonTimeline.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/util/timeline/SingletonTimeline.java
new file mode 100644
index 00000000..526a95f5
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/util/timeline/SingletonTimeline.java
@@ -0,0 +1,73 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2019, Tamas Szabo, itemis AG, Gabor Bergmann, IncQuery Labs Ltd.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.viatra.runtime.matchers.util.timeline;
+
+import java.util.Collections;
+
+import tools.refinery.viatra.runtime.matchers.util.Direction;
+import tools.refinery.viatra.runtime.matchers.util.Signed;
+
+/**
+ * A timeline which solely consists of one timestamp value, representing a single insertion. Intuitively, a singleton
+ * timeline always represents a bump which starts at the given timestamp and lasts till plus infinity.
+ * 
+ * @author Tamas Szabo
+ * @since 2.4
+ */
+public class SingletonTimeline<Timestamp extends Comparable<Timestamp>> extends Timeline<Timestamp> {
+
+    protected final Timestamp start;
+
+    SingletonTimeline(final Timestamp timestamp) {
+        this.start = timestamp;
+    }
+
+    SingletonTimeline(final Diff<Timestamp> diff) {
+        if (diff.size() != 1 || diff.get(0).getDirection() == Direction.DELETE) {
+            throw new IllegalArgumentException("There is only a single (insert) timestamp in the singleton timestamp!");
+        } else {
+            this.start = diff.get(0).getPayload();
+        }
+    }
+
+    @Override
+    public Signed<Timestamp> getSigned(final int index) {
+        return new Signed<>(Direction.INSERT, this.getUnsigned(index));
+    }
+
+    @Override
+    public Timestamp getUnsigned(final int index) {
+        if (index != 0) {
+            throw new IllegalArgumentException("There is only a single (insert) timestamp in the singleton timestamp!");
+        } else {
+            return this.start;
+        }
+    }
+
+    @Override
+    public int size() {
+        return 1;
+    }
+
+    @Override
+    public boolean isPresentAtInfinity() {
+        return true;
+    }
+
+    @Override
+    public Iterable<Signed<Timestamp>> asChangeSequence() {
+        return Collections.singletonList(this.getSigned(0));
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return false;
+    }
+
+}