1 files changed, 48 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/TupleValueProvider.java b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/TupleValueProvider.java
new file mode 100644
index 00000000..79193516
--- /dev/null
+++ b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/tuple/TupleValueProvider.java
@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2013, Zoltan Ujhelyi, 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.tuple;
+
+import java.util.Map;
+
+import tools.refinery.viatra.runtime.matchers.psystem.IValueProvider;
+
+/**
+ * @author Zoltan Ujhelyi
+ * @since 1.7
+ */
+public class TupleValueProvider implements IValueProvider {
+
+    final ITuple tuple;
+    final Map<String, Integer> indexMapping;
+    
+    /**
+     * Wraps a tuple with an index mapping
+     * @param tuple
+     * @param indexMapping
+     */
+    public TupleValueProvider(ITuple tuple, Map<String, Integer> indexMapping) {
+        super();
+        this.tuple = tuple;
+        this.indexMapping = indexMapping;
+    }
+
+    @Override
+    public Object getValue(String variableName) {
+        Integer index = indexMapping.get(variableName);
+        if (index == null) {
+            throw new IllegalArgumentException(String.format("Variable %s is not present in mapping.", variableName));
+        }
+        Object value = tuple.get(index);
+        if (value == null) {
+            throw new IllegalArgumentException(String.format("Variable %s is not found using index %d.", variableName, index));
+        }
+        return value;
+    }
+
+}