X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=407d843a51f0651d32e51214cf83df36199fb767;hb=f699bd804e3216b451aba17bc79f94504ff98612;hp=b326468aff26137e5e4a56ffcad3741c87d76b3d;hpb=6a2ea790f843e058c7e67d3c7d1deebadcfe1fd5;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index b326468..407d843 100644
--- a/src/edu/berkeley/sbp/Input.java
+++ b/src/edu/berkeley/sbp/Input.java
@@ -6,22 +6,33 @@ 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 {
+/** a stream of tokens to be parsed */
+public interface Input<Token> {
 
-    /** this is declared abstract as a way of forcing subclasses to provide a thoughtful implementation */
-    public abstract String toString();
+    /** returns the token just beyond the current location and advances beyond it */
+    public Token           next() throws IOException;
 
-    /** 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();
-    }
+    /** returns the location the input stream is currently at */
+    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");
+            }
+        }
+    }
 }