X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FInput.java;h=13c45d49de0476210819bc76befe901ce5c7e653;hb=f8adfc66d98670be6553965d7ee9e6c998a4e0a6;hp=407d843a51f0651d32e51214cf83df36199fb767;hpb=c8a17fdd2e149fe5feecd96c71b7f2cab286ab96;p=sbp.git
diff --git a/src/edu/berkeley/sbp/Input.java b/src/edu/berkeley/sbp/Input.java
index 407d843..13c45d4 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.*;
@@ -6,7 +8,7 @@ import java.lang.ref.*;
import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
-/** a stream of tokens to be parsed */
+/** a stream of Tokens to be parsed */
public interface Input {
/** returns the token just beyond the current location and advances beyond it */
@@ -14,25 +16,51 @@ public interface Input {
/** returns the location the input stream is currently at */
public Location getLocation();
+
+ /** should return a short string describing where the input is coming from */
+ public String getName();
+
+ /**
+ * Optional: If possible, 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 r);
+
+ /** a location (position) in the input stream -- between tokens */
+ public static interface Location extends Comparable {
+
+ /** return the region between this location and loc */
+ public Region createRegion(Location loc);
- /** a location between tokens in the input stream */
- public static interface Location extends Comparable {
public String toString();
+
+ /** the location following this one */
+ public Location next();
+
+ /** the location preceding this one */
+ public Location prev();
}
- public static class Region /* implements Topology> */ {
- 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");
- }
- }
+ /** a contiguous set of Locations */
+ public static interface Region /* implements Topology> */ {
+
+ /**
+ * 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 getStart();
+
+ /** The location of the end of this region */
+ public abstract Location getEnd();
+
}
+
}