Update tape interface

This adds a seekTo method, among other things

3 files changed, 22 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/esodata/DoubleTape.java b/base/src/main/java/bjc/utils/esodata/DoubleTape.java
index 520ab5e..e32045e 100644
--- a/base/src/main/java/bjc/utils/esodata/DoubleTape.java
+++ b/base/src/main/java/bjc/utils/esodata/DoubleTape.java
@@ -134,6 +134,10 @@ public class DoubleTape<T> implements Tape<T>, DoubleSided {
 		return succ;
 	}
 
+	public boolean seekTo(int tgtPos) {
+		return front.seekTo(tgtPos);
+	}
+
 	@Override
 	public void flip() {
 		final Tape<T> tmp = front;
diff --git a/base/src/main/java/bjc/utils/esodata/SingleTape.java b/base/src/main/java/bjc/utils/esodata/SingleTape.java
index 636c04c..d57bc7f 100644
--- a/base/src/main/java/bjc/utils/esodata/SingleTape.java
+++ b/base/src/main/java/bjc/utils/esodata/SingleTape.java
@@ -163,6 +163,22 @@ public class SingleTape<T> implements Tape<T> {
 		return true;
 	}
 
+	public boolean seekTo(int tgtPos) {
+		if(tgtPos < 0)
+			return false;
+
+		if(tgtPos >= backing.size() - 1)
+			if(autoExtend)
+				while(tgtPos >= backing.size() - 1)
+					backing.add(null);
+			else
+				return false;
+
+		pos = tgtPos;
+
+		return true;
+	}
+
 	@Override
 	public int hashCode() {
 		final int prime = 31;
diff --git a/base/src/main/java/bjc/utils/esodata/Tape.java b/base/src/main/java/bjc/utils/esodata/Tape.java
index ae218ac..2c7f517 100644
--- a/base/src/main/java/bjc/utils/esodata/Tape.java
+++ b/base/src/main/java/bjc/utils/esodata/Tape.java
@@ -112,4 +112,6 @@ public interface Tape<T> {
 	 * @return Whether the cursor was moved right.
 	 */
 	boolean right(int amt);
+
+	boolean seekTo(int pos);
 }