- /** a sequence of input tokens; returns null when EOF is reached */
- public static interface Stream<Tok> {
- public Tok next(int numstates, int resets, int waits) throws IOException;
- public abstract Location getLocation();
- }
+ /** the current location within the input stream */
+ public Location<Token> getLocation();
+
+ /** returns the token just beyond the current location and advances beyond it */
+ public Token next() throws IOException;
+
+ /** a short string describing where the input is coming from, such as a filename */
+ public String getName();
+
+ /**
+ * <b>Optional:</b> <i>If possible</i>, this method will return a
+ * rendering of the input region (for example, if the input is a
+ * region of characters, it would be those characters) --
+ * otherwise, returns null. In any case, the string returned
+ * will be no more than <tt>maxLength</tt> characters long;
+ * typically ellipses will be inserted to perform truncation.
+ */
+ public abstract String showRegion(Region<Token> r, int maxLength);
+
+ /** <font color=purple>a location (position) in the input stream <i>between tokens</i></font> */
+ public static interface Location<Token> extends Comparable<Location> {
+
+ /** return the region between this location and <tt>loc</tt> */
+ public Region<Token> createRegion(Location<Token> loc);