inglorious fix: when detecting an EOF in the lexer, throw a runtime exception

  to stop the evaluation loop. 

git-svn-id: https://cobra.cs.uni-duesseldorf.de/prob/trunk/experimental/plagge/probkodkod@7393 7aec93f6-bc54-0410-ac70-7d7c9efa889a

src/de/stups/probkodkod/EOFLexer.java

@@ -19,7 +19,6 @@ import de.stups.probkodkod.parser.node.Token;
  * @author plagge
  */
 public class EOFLexer extends Lexer {
-
 	public EOFLexer(final PushbackReader in) {
 		super(in);
 	}
@@ -39,10 +38,15 @@ public class EOFLexer extends Lexer {
 	}
 
 	private Token filter(Token token) {
-		if (token instanceof TFullstop) {
+		if (token instanceof EOF)
+			throw new AbortException();
+		else if (token instanceof TFullstop) {
 			token = new EOF();
 		}
 		return token;
 	}
 
+	public static class AbortException extends RuntimeException {
+		private static final long serialVersionUID = 4042645224685292559L;
+	}
 }

src/de/stups/probkodkod/KodkodInteraction.java

@@ -48,11 +48,15 @@ public class KodkodInteraction {
 		final Lexer lexer = new EOFLexer(in);
 		final Parser parser = new Parser(lexer);
 
+		try {
 			while (!session.isStopped()) {
 				final Start tree = parser.parse();
 				tree.apply(analysis);
 				pto.flush();
 			}
+		} catch (EOFLexer.AbortException e) {
+			logger.info("EOF reached");
+		}
 
 		logger.info("Kodkod session finished");
 	}