--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plparser/PLScanner.java	Wed Sep 01 15:23:37 2010 +0900
@@ -0,0 +1,39 @@
+package plparser;
+
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public interface PLScanner<Node> {
+
+	String filename();
+	int lineno();
+
+	public Token<Node> nextToken();
+
+	public boolean hasRemaining();
+
+	public PLScanner<Node> pushScannerFile(InputStream newfile,	String prompt);
+	PLScanner<Node> prev();
+	PLScanner<Node> pushScanner(String exp);
+	PLScanner<Node> pushScannerFile(String file) throws FileNotFoundException;
+	PLScanner<Node> popScanner();
+	public PLScanner<Node> set(String exp);
+
+	/*
+	 * Read From File
+	 *    We cannot read symbol bigger than Buffersize
+	 */
+	public PLScanner<Node> setFile(String file)
+			throws FileNotFoundException;
+
+	public PLScanner<Node> set(InputStreamReader file);
+
+	public void error(String err);
+
+	public Iterable<Token<Node>> scanToken(String exp);
+
+	public Iterable<Token<Node>> scanToken(FileReader file);
+
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plparser/PLScannerImpl.java	Wed Sep 01 15:23:37 2010 +0900
@@ -0,0 +1,104 @@
+package plparser;
+
+import java.io.FileReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.Iterator;
+
+public abstract class PLScannerImpl<Node> implements PLScanner<Node> {
+
+	public int lineno;
+	public Token<Node> nextToken;
+	public Dictionary<Node> dict;
+	public PLScanner<Node> next;
+	public InputStreamReader file;
+	public String filename;
+	public PLScanner<Node> prev;
+	public Token<Node> nullToken;
+	public String prompt;
+	public static final int BufferSize = 4096;
+
+	public PLScannerImpl() {
+		super();
+	}
+
+	public PLScannerImpl(PLScannerImpl<Node> plScannerImpl,
+			Dictionary<Node> dict, Token<Node> nullToken) {
+		this.dict = dict; 
+		this.nullToken = nullToken;
+	}
+
+
+	public PLScanner<Node> popScanner() {
+		return prev;
+	}
+
+	private PLScanner<Node> findFileName() {
+		for(PLScanner<Node> s = this;s!=null ; s = s.prev()) {
+			if (s.filename()!=null) return s;
+		}
+		return null;
+	}
+	/*
+	 * Read From String
+	 */
+
+	public void error(String err) {
+		PLScanner<Node> s = findFileName();
+		if (s!=null) {
+			System.err.print(s.filename()+":"+s.lineno()+": ");
+		}
+		System.err.println("error: "+err);
+	}
+
+	public Iterable<Token<Node>> scanToken(String exp) {
+		set(exp);
+		return iterator();
+	}
+
+	public Iterable<Token<Node>> scanToken(FileReader file) {
+		set(file);
+		return iterator();
+	}
+
+	private Iterable<Token<Node>> iterator() {
+		return new Iterable<Token<Node>>() {
+			public Iterator<Token<Node>> iterator() {
+				return new Iterator<Token<Node>>() {
+					public boolean hasNext() {
+						return hasRemaining();
+					}
+					public Token<Node> next() {
+						return nextToken();
+					}
+					public void remove() {
+					}
+				};
+			}
+		};
+	}
+
+	public PLScanner<Node> setFile(InputStream newfile, String prompt) {
+		this.filename = newfile.toString();
+		nextToken = nullToken;
+		this.prompt = prompt;
+		set(new InputStreamReader(newfile));
+		return this;
+	}
+
+	@Override
+	public String filename() {
+		return filename;
+	}
+
+	@Override
+	public int lineno() {
+		return lineno;
+	}
+
+	@Override
+	public PLScanner<Node> prev() {
+		return prev;
+	}
+
+}
\ No newline at end of file

--- a/src/plparser/PropertyListParser.java	Mon Aug 30 12:35:23 2010 +0900
+++ b/src/plparser/PropertyListParser.java	Wed Sep 01 15:23:37 2010 +0900
@@ -8,7 +8,7 @@
 public class PropertyListParser<Node extends Property> {
 	PropertyListNodeFactory<Node> lf;
 	Token<Node> nextToken;
-	public PropertyListScanner<Node> scanner;
+	public PLScanner<Node> scanner;
 	private Dictionary<Node> dict;
 	// scope is necessary if you have to parse nested name scope
 //	private PropertyListScope<Node> scope;
@@ -49,7 +49,6 @@
 
 	public Node parse() {
 		if (scanner==null) return null; // internal error
-		if (scanner.cb==null) return null; // nothing to do
 		nextToken();
 		return term();
 	}
@@ -59,7 +58,7 @@
 		scanner = scanner.pushScanner(exp);
 		n = parse();
 		scanner = scanner.popScanner();
-		nextToken = scanner.nextToken;
+		nextToken = scanner.nextToken();
 		return n;
 		
 	}
@@ -90,7 +89,7 @@
 			n=parse();
 		} while(scanner.hasRemaining());
 		scanner = scanner.popScanner();
-		nextToken = scanner.nextToken;
+		nextToken = scanner.nextToken();
 		return n;
 	}
 

--- a/src/plparser/PropertyListScanner.java	Mon Aug 30 12:35:23 2010 +0900
+++ b/src/plparser/PropertyListScanner.java	Wed Sep 01 15:23:37 2010 +0900
@@ -6,11 +6,10 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.CharBuffer;
-import java.util.Iterator;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class PropertyListScanner<Node> {
+public class PropertyListScanner<Node> extends PLScannerImpl<Node> implements PLScanner<Node> {
 
 	//  We cannot make Generic Singleton pattern
 	//	static PropertyListScanner scanner = new PropertyListScanner();
@@ -31,18 +30,8 @@
 	 *     2010/8 Shinji Kono    
 	 */
 
-	public int lineno;
 	public Matcher scan;
-	public Token<Node> nextToken;
-	public Dictionary<Node> dict;
-	public PropertyListScanner<Node> next;
-	protected CharBuffer cb;
-	private InputStreamReader file;
-	private String filename;
-	public PropertyListScanner<Node> prev;
-	public Token<Node> nullToken ;
-	public String prompt;
-
+	private CharBuffer cb;
 	public PropertyListScanner(Dictionary<Node> dict) {
 		this.dict = dict;
 		nullToken = new Token<Node>("",TokenID.NULL);
@@ -59,44 +48,28 @@
 
 
 	// Pattern must contain exact 1 group
-	public static Pattern tokenPat = Pattern.compile(
+	private static Pattern tokenPat = Pattern.compile(
 			"([={}(),;])"
 	);
-	public static Pattern namePat  = Pattern.compile("([_a-zA-Z][\\@\\w]*)");
-	public static final Pattern numPat  = Pattern.compile("([0-9]+)");
-	public static final Pattern stringPat1  = Pattern.compile("\\\"([^\"]*)\\\"");
-	public static final Pattern stringPat  = Pattern.compile("\\'([^\\']*)\\'");
-	public static final Pattern stringPat1cont  = Pattern.compile("\\\"([^\"]*)$");
-	public static final Pattern stringPatCont  = Pattern.compile("\\'([^\\']*)$");
-	public static final Pattern stringPat1End  = Pattern.compile("([^\"]*)\\\"");
-	public static final Pattern stringPatEnd  = Pattern.compile("([^\\']*)\'");
-	public static final Pattern commentPat  = Pattern.compile("(//.*)");
-	public static final Pattern commentPat1  = Pattern.compile("(/\\*)");
-	public static final Pattern commentPat1End  = Pattern.compile("(.*\\*/)");
-	public static final Pattern errorPat = Pattern.compile("([^\\s])");
-	public static final Pattern anyPat = Pattern.compile("(.)");
-	private static final int BufferSize = 4096;
-
-	/*
-	 * Get next token
-	 * 
-	 *    No looking up method nor put back. It never returns null but
-	 *    may return nullToken. So nextToken.type is always valid.
-	 *    nullToken means the end of the input.
-	 *    
-	 *    Token is a syntax element and it may have macro binding as
-	 *    predicate, infix or prefix operator. To get the value, use
-	 *    makeVariable(). Operator order for infix and prefix is in
-	 *    Token.order. TokenID.order is default order for fix element and
-	 *    currently never used.
-	 *    
-	 *    When matcher hit an end of the input, hasRemaining() method try
-	 *    to extend the input using extendInput().
-	 */
-
+	private static Pattern namePat  = Pattern.compile("([_a-zA-Z][\\@\\w]*)");
+	private static final Pattern numPat  = Pattern.compile("([0-9]+)");
+	private static final Pattern stringPat1  = Pattern.compile("\\\"([^\"]*)\\\"");
+	private static final Pattern stringPat  = Pattern.compile("\\'([^\\']*)\\'");
+	private static final Pattern stringPat1cont  = Pattern.compile("\\\"([^\"]*)$");
+	private static final Pattern stringPatCont  = Pattern.compile("\\'([^\\']*)$");
+	private static final Pattern stringPat1End  = Pattern.compile("([^\"]*)\\\"");
+	private static final Pattern stringPatEnd  = Pattern.compile("([^\\']*)\'");
+	private static final Pattern commentPat  = Pattern.compile("(//.*)");
+	private static final Pattern commentPat1  = Pattern.compile("(/\\*)");
+	private static final Pattern commentPat1End  = Pattern.compile("(.*\\*/)");
+	private static final Pattern errorPat = Pattern.compile("([^\\s])");
+	private static final Pattern anyPat = Pattern.compile("(.)");
+	
+	@Override
 	public Token<Node> nextToken() {
 		String s;
 		nextToken = nullToken;
+		if (cb==null) return nextToken;
 		while(hasRemaining()) {
 			scan.reset(); // to tell CharBuffer is modified
 			if ((s=next(tokenPat))!=null) {
@@ -199,6 +172,7 @@
 		}
 	}
 
+	@Override
 	public boolean hasRemaining() {
 		return cb.hasRemaining()||extendInput();
 	}
@@ -226,35 +200,8 @@
 		return false;
 	}
 
-	protected PropertyListScanner<Node> pushScanner(String exp) {
-		// Save current matcher for nested parsing
-		return new PropertyListScanner<Node>(this,dict,nullToken).set(exp);
-	}
-
-	protected PropertyListScanner<Node> pushScannerFile(String newfile) throws FileNotFoundException {
-		// Save current matcher for nested file
-		return new PropertyListScanner<Node>(this,dict,nullToken).setFile(newfile);
-	}
-
-	public PropertyListScanner<Node> pushScannerFile(InputStream newfile,String prompt) {
-		return new PropertyListScanner<Node>(this,dict,nullToken).setFile(newfile,prompt);
-	}
-
-	protected PropertyListScanner<Node> popScanner() {
-		return prev;
-	}
-
-	private PropertyListScanner<Node> findFileName() {
-		for(PropertyListScanner<Node> s = this;s!=null ; s = s.prev) {
-			if (s.filename!=null) return s;
-		}
-		return null;
-	}
-	/*
-	 * Read From String
-	 */
-
-	public PropertyListScanner<Node> set(String exp) {
+	@Override
+	public PLScanner<Node> set(String exp) {
 		cb = CharBuffer.wrap(exp);
 		scan = tokenPat.matcher(cb);
 		filename = null; file = null;
@@ -266,14 +213,16 @@
 	 * Read From File
 	 *    We cannot read symbol bigger than Buffersize
 	 */
-	public PropertyListScanner<Node> setFile(String file) throws FileNotFoundException {
+	@Override
+	public PLScanner<Node> setFile(String file) throws FileNotFoundException {
 		this.filename = file;
 		nextToken = nullToken;
 		set(new FileReader(file));
 		return this;
 	}
 
-	public PropertyListScanner<Node> set(InputStreamReader file) {
+	@Override
+	public PLScanner<Node> set(InputStreamReader file) {
 		this.file = file;
 		cb = CharBuffer.allocate(BufferSize);
 		try {
@@ -293,52 +242,20 @@
 		return this;
 	}
 
-	public void error(String err) {
-		PropertyListScanner<Node> s = findFileName();
-		if (s!=null) {
-			System.err.print(s.filename+":"+s.lineno+": ");
-		}
-		System.err.println("error: "+err);
-	}
 
-	/*
-	 * Iterator for Test Routing
-	 *    for(Token<Node> t: scanner.scanToken(FileReader(file)) { ... }
-	 */
-
-	public Iterable<Token<Node>> scanToken(String exp) {
-		set(exp);
-		return iterator();
-	}
-
-	public Iterable<Token<Node>> scanToken(FileReader file) {
-		set(file);
-		return iterator();
+	@Override
+	public PLScanner<Node> pushScannerFile(InputStream newfile, String prompt) {
+		return new PropertyListScanner<Node>(this,dict,nullToken).setFile(newfile,prompt);
 	}
 
-	private Iterable<Token<Node>> iterator() {
-		return new Iterable<Token<Node>>() {
-			public Iterator<Token<Node>> iterator() {
-				return new Iterator<Token<Node>>() {
-					public boolean hasNext() {
-						return hasRemaining();
-					}
-					public Token<Node> next() {
-						return nextToken();
-					}
-					public void remove() {
-					}
-				};
-			}
-		};
+	@Override
+	public PLScanner<Node> pushScanner(String exp) {
+		return new PropertyListScanner<Node>(this,dict,nullToken).set(exp);
 	}
 
-	private PropertyListScanner<Node> setFile(InputStream newfile,String prompt) {
-		this.filename = newfile.toString();
-		nextToken = nullToken;
-		this.prompt = prompt;
-		set(new InputStreamReader(newfile));
-		return this;
+	@Override
+	public PLScanner<Node> pushScannerFile(String newfile)
+			throws FileNotFoundException {
+		return new PropertyListScanner<Node>(this,dict,nullToken).setFile(newfile);
 	}
-
 }

--- a/src/plparser/TestScanner.java	Mon Aug 30 12:35:23 2010 +0900
+++ b/src/plparser/TestScanner.java	Wed Sep 01 15:23:37 2010 +0900
@@ -6,7 +6,7 @@
 
 public class TestScanner {
 	
-	public static PropertyListScanner<Property> scan;
+	public static PLScanner<Property> scan;
 
 	public static void main(String arg[]) {
 		initScanner();