1 files changed, 27 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/resumable/Resumable.java b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/resumable/Resumable.java
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index 00000000..2861df20
--- /dev/null
+++ b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/resumable/Resumable.java
@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2016, Tamas Szabo, Istvan Rath and Daniel Varro
+ * 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.resumable;
+
+/**
+ * A resumable lazily folds its state towards higher timestamps. Folding shall be done in the increasing order of
+ * timestamps, and it shall be interrupted after each step. The resumable can then be instructed to resume the folding,
+ * one step at a time.
+ * 
+ * @author Tamas Szabo
+ * @since 2.4
+ */
+public interface Resumable<Timestamp extends Comparable<Timestamp>> {
+
+    /**
+     * Returns the smallest timestamp where lazy folding shall be resumed, or null if there is no more folding to do in this
+     * resumable.
+     */
+    public Timestamp getResumableTimestamp();
+
+}