checkpoint

[sbp.git] / src / edu / berkeley / sbp / Input.java

diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index b326468..d19b208 100644 (file)
--- a/src/edu/berkeley/sbp/Input.java
+++ b/src/edu/berkeley/sbp/Input.java
@@ -6,22 +6,28 @@ 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 {
+/** <font color=purple>a stream of <tt>Token</tt>s to be parsed</font> */
+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();
+
+    /** <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();
     }
+
+    /** <font color=purple>a contiguous set of <tt>Location</tt>s</font> */
+    public static interface Region<Token> /* implements Topology<Location<Tok>> */ {
+    }
+
 }