X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=407d843a51f0651d32e51214cf83df36199fb767;hb=aaa5d101e054dc548e7ef7831b1fcb7913a4d4d4;hp=eeb3cc1cff339f67ffa0402d4aaf3ff568fc9e07;hpb=e74711e9cb411d80137ebd1f8d9b3bc9a0886f60;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index eeb3cc1..407d843 100644
--- a/src/edu/berkeley/sbp/Input.java
+++ b/src/edu/berkeley/sbp/Input.java
@@ -10,15 +10,29 @@ import edu.berkeley.sbp.util.*;
 public interface Input<Token> {
 
     /** returns the token just beyond the current location and advances beyond it */
-    public Token    next() throws IOException;
+    public Token           next() throws IOException;
 
     /** returns the location the input stream is currently at */
-    public Location getLocation();
+    public Location<Token> getLocation();
 
-    /** a location *between tokens* in the input stream */
-    public static interface Location {
+    /** a location <i>between tokens<i> in the input stream */
+    public static interface Location<Tok> extends Comparable<Location> {
         public String toString();
     }
+
+    public static class Region<Loc extends Location> /* implements Topology<Location<Tok>> */ {
+        public final Loc start;
+        public final Loc end;
+        public String toString() { return start+"-"+end; }
+        public Region(Loc a, Loc b) {
+            switch(a.compareTo(b)) {
+                case -1:
+                case  0: start=a; end=b; return;
+                case  1: start=b; end=a; return;
+                default: throw new Error("impossible");
+            }
+        }
+    }
 }