visitor.ReplaceLabels: for replacing labels in an expression

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11165 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/parser/visitor/ReplaceLabels.java

@@ -0,0 +1,67 @@
+//==============================================================================
+//	
+//	Copyright (c) 2016-
+//	Authors:
+//	* Joachim Klein <klein@tcs.inf.tu-dresden.de> (TU Dresden)
+//	
+//------------------------------------------------------------------------------
+//	
+//	This file is part of PRISM.
+//	
+//	PRISM is free software; you can redistribute it and/or modify
+//	it under the terms of the GNU General Public License as published by
+//	the Free Software Foundation; either version 2 of the License, or
+//	(at your option) any later version.
+//	
+//	PRISM is distributed in the hope that it will be useful,
+//	but WITHOUT ANY WARRANTY; without even the implied warranty of
+//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//	GNU General Public License for more details.
+//	
+//	You should have received a copy of the GNU General Public License
+//	along with PRISM; if not, write to the Free Software Foundation,
+//	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//	
+//==============================================================================
+
+
+package parser.visitor;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import parser.ast.ExpressionLabel;
+
+/** Visitor for replacing some labels in an expression by other labels */
+public class ReplaceLabels extends ASTTraverseModify
+{
+	/** The replacement map */
+	private Map<String, String> replacements;
+
+	/** Constructor for multiple replacements (from -> to) */
+	public ReplaceLabels(Map<String, String> replacements)
+	{
+		this.replacements = replacements;
+	}
+
+	/** Constructor for a single replacement */
+	public ReplaceLabels(String labelFrom, String labelTo)
+	{
+		replacements = new HashMap<String,String>();
+		replacements.put(labelFrom, labelTo);
+	}
+
+	@Override
+	public Object visit(ExpressionLabel e)
+	{
+		if (e.getName() == null)
+			return e;
+
+		String replacement = replacements.get(e.getName());
+		if (replacement != null)
+			return new ExpressionLabel(replacement);
+
+		return e;
+	}
+
+}