X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=6e4b0eefb63de68177f1fb80a286d07bedb18aff;hp=9948ae40a2b69bf8cf42cd7198a214a35ef019b6;hb=2c05c84a714f54b3bc026f51416492ddb13f33b1;hpb=82f9b8d4a2fadb14cb004e5cc9f14944458f2e6c

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index 9948ae4..6e4b0ee 100644
--- a/src/edu/berkeley/sbp/Input.java
+++ b/src/edu/berkeley/sbp/Input.java
@@ -1,3 +1,5 @@
+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp;
 import java.io.*;
 import java.util.*;
@@ -6,7 +8,7 @@ import java.lang.ref.*;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
 
-/** a stream of tokens to be parsed */
+/** <font color=purple>a stream of <tt>Token</tt>s to be parsed</font> */
 public interface Input<Token> {
 
     /** returns the token just beyond the current location and advances beyond it */
@@ -15,13 +17,47 @@ public interface Input<Token> {
     /** returns the location the input stream is currently at */
     public Location<Token> getLocation();
 
-    /** a location <i>between tokens<i> in the input stream */
-    public static interface Location<Tok> extends Comparable<Location> {
+    /**
+     *  <b>Optional:</b> <i>If possible</i>, this method will return a
+     *  <60 char long rendering of the input region (for example, if
+     *  the input is a region of characters, it would be those
+     *  characters, possibly with ellipses in the middle to truncate
+     *  the length) -- otherwise, returns null.
+     */
+    public abstract String showRegion(Region<Token> r);
+
+    /** <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);
+
         public String toString();
-        public Region<Tok> createRegion(Location<Tok> loc);
+
+        /** the location following this one */
+        public Location next();
+
+        /** the location preceding this one */
+        public Location prev();
+    }
+
+    /** <font color=purple>a contiguous set of <tt>Location</tt>s</font> */
+    public static interface Region<Token> /* implements Topology<Location<Tok>> */ {
+
+        /**
+         *  the toString() method of Region should return a <80char
+         *  "rendition" of the input region, if possible
+         */
+        public abstract String toString();
+        
+        /** The location of the start of this region */
+        public abstract Location<Token> getStart();
+
+        /** The location of the end of this region */
+        public abstract Location<Token> getEnd();
+
     }
 
-    public static interface Region<Tok> /* implements Topology<Location<Tok>> */ { }
 }