X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=6e4b0eefb63de68177f1fb80a286d07bedb18aff;hp=d8374cdf08e35af3a76c9023e76708841f0f692f;hb=2c05c84a714f54b3bc026f51416492ddb13f33b1;hpb=a7b84506c2e1ed63343db215f76afced082e2826

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index d8374cd..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.*;
@@ -6,16 +8,56 @@ import java.lang.ref.*;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
 
-/** a token of input -- note that this represents an <i>actual input token</i> rather than an <tt>Element</tt> which <i>matches</i> a token */
-public interface Input<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 */
+    public Location<Token> getLocation();
+
+    /**
+     *  <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);
 
-    public Tok next(int numstates, int resets, int waits) throws IOException;
-    public abstract Location getLocation();
+    /** <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);
 
-    /** a location *between tokens* in the input stream */
-    public static interface Location {
         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>> */ {
+
+        /**
+         *  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();
+
+    }
+
 }