X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=7a2df1aee721d512ea2acce0f85bb1c52b7cdadd;hp=c16947d24f18600ae7b0c4ee0bd0e76fa0fd1e49;hb=dc9bb3a45ed306e2e35549076842b3e74efecb48;hpb=3ee451bce342d4bb61ad6235ba57bdf817bfdd1a

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index c16947d..7a2df1a 100644
--- a/src/edu/berkeley/sbp/Input.java
+++ b/src/edu/berkeley/sbp/Input.java
@@ -1,33 +1,61 @@
-// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+// (C) 2006-2007 all rights reserved; see LICENSE file for BSD-style license
 
 package edu.berkeley.sbp;
 import java.io.*;
 import java.util.*;
-import java.lang.reflect.*;
-import java.lang.ref.*;
-import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
 
+// FEATURE: Region implements Topology<Location<Tok>>
+
 /** <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 */
-    public Token           next() throws IOException;
-
-    /** returns the location the input stream is currently at */
+    /** the current location within the input stream */
     public Location<Token> getLocation();
 
-    /** <font color=purple>a location (position) in the input stream -- <i>between tokens</i></font> */
+    /** 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);
 
         public String toString();
+
+        /** 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>> */ {
+    public static interface Region<Token> {
+
+        /** should return less than 80 chars 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();
+
     }
 
 }