1 files changed, 45 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/context/IInputKey.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/context/IInputKey.java
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+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/context/IInputKey.java
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+/*******************************************************************************
+ * Copyright (c) 2010-2015, Bergmann Gabor, 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.context;
+
+/**
+ * An input key identifies an input (extensional) relation, such as the instance set of a given node or edge type, or the direct containment relation.
+ * 
+ * <p> The input key, at the very minimum, is associated with an arity (number of columns), a user-friendly name, and a string identifier (for distributive purposes). 
+ * 
+ * <p> The input key itself must be an immutable data object that properly overrides equals() and hashCode(). 
+ * It must be instantiable without using the query context object, so that query specifications may construct the appropriate PQueries. 
+ * 
+ * @author Bergmann Gabor
+ *
+ */
+public interface IInputKey {
+
+    /**
+     * A user-friendly name that can be shown on screen for debug purposes, included in exceptions, etc.
+     */
+    public String getPrettyPrintableName();
+    /**
+     * An internal string identifier that can be used to uniquely identify to input key (relevant for distributed applications).
+     */
+    public String getStringID();
+    
+    /**
+     * The width of tuples in this relation.
+     */
+    public int getArity();
+    
+    /**
+     * Returns true iff instance tuples of the key can be enumerated.
+     * <p> If false, the runtime can only test tuple membership in the extensional relation identified by the key, but not enumerate member tuples in general.
+     */
+    boolean isEnumerable();
+    
+    
+}