1 files changed, 64 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Parameter.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Parameter.java
new file mode 100644
index 000000000..b4c56346e
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/p2/metadata/expression/Parameter.java
@@ -0,0 +1,64 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Cloudsmith Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Cloudsmith Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.internal.p2.metadata.expression;
+
+import org.eclipse.equinox.p2.metadata.expression.IEvaluationContext;
+
+/**
+ * The abstract base class for the indexed and keyed parameters
+ */
+public class Parameter extends Expression {
+	final int position;
+
+	Parameter(int position) {
+		this.position = position;
+	}
+
+	public int compareTo(Expression e) {
+		int cmp = super.compareTo(e);
+		if (cmp == 0)
+			cmp = position - ((Parameter) e).position;
+		return cmp;
+	}
+
+	public boolean equals(Object o) {
+		if (o == this)
+			return true;
+		if (o == null)
+			return false;
+		return getClass() == o.getClass() && position == ((Parameter) o).position;
+	}
+
+	public Object evaluate(IEvaluationContext context) {
+		return context.getParameter(position);
+	}
+
+	public int getExpressionType() {
+		return TYPE_PARAMETER;
+	}
+
+	public String getOperator() {
+		return OPERATOR_PARAMETER;
+	}
+
+	public int getPriority() {
+		return PRIORITY_VARIABLE;
+	}
+
+	public int hashCode() {
+		return 31 * (1 + position);
+	}
+
+	public void toString(StringBuffer bld, Variable rootVariable) {
+		bld.append('$');
+		bld.append(position);
+	}
+}