Start splitting into maven modules

1 files changed, 255 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/esodata/SingleTape.java b/base/src/main/java/bjc/utils/esodata/SingleTape.java
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index 0000000..c50be92
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+++ b/base/src/main/java/bjc/utils/esodata/SingleTape.java
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+package bjc.utils.esodata;
+
+import java.util.ArrayList;
+
+/**
+ * A tape is a one-dimensional array that can only be accessed in one position
+ * at a time.
+ *
+ * A tape is essentially a 1D array with a cursor attached to it, and you can
+ * only affect elements at that cursor. The size of the array is theoretically
+ * unbounded to the right, but in practice bounded by available memory.
+ *
+ * You can choose whether or not you want the tape to automatically extend
+ * itself to the right with null elements by specifying its auto-extension
+ * policy.
+ *
+ * @param <T>
+ *                The element type of the tape.
+ *
+ * @author bjculkin
+ */
+public class SingleTape<T> implements Tape<T> {
+	protected ArrayList<T>	backing;
+	protected int		pos;
+
+	protected boolean autoExtend;
+
+	/**
+	 * Create a new tape with the specified contents that doesn't
+	 * autoextend.
+	 */
+	public SingleTape(T... vals) {
+		autoExtend = false;
+
+		backing = new ArrayList(vals.length);
+
+		for(T val : vals) {
+			backing.add(val);
+		}
+	}
+	/**
+	 * Create a new empty tape that doesn't autoextend.
+	 */
+	public SingleTape() {
+		this(false);
+	}
+
+	/**
+	 * Create a new empty tape that follows the specified auto-extension
+	 * policy.
+	 *
+	 * @param autoExtnd
+	 *                Whether or not to auto-extend the tape to the right w/
+	 *                nulls.
+	 */
+	public SingleTape(final boolean autoExtnd) {
+		autoExtend = autoExtnd;
+
+		backing = new ArrayList<>();
+	}
+
+	/**
+	 * Get the item the tape is currently on.
+	 *
+	 * @return The item the tape is on.
+	 */
+	@Override
+	public T item() {
+		return backing.get(pos);
+	}
+
+	/**
+	 * Set the item the tape is currently on.
+	 *
+	 * @param itm
+	 *                The new value for the tape item.
+	 */
+	@Override
+	public void item(final T itm) {
+		backing.set(pos, itm);
+	}
+
+	/**
+	 * Get the current number of elements in the tape.
+	 *
+	 * @return The current number of elements in the tape.
+	 */
+	@Override
+	public int size() {
+		return backing.size();
+	}
+
+	@Override
+	public int position() {
+		return pos;
+	}
+
+	/**
+	 * Insert an element before the current item.
+	 *
+	 * @param itm
+	 *                The item to add.
+	 */
+	@Override
+	public void insertBefore(final T itm) {
+		backing.add(pos, itm);
+	}
+
+	/**
+	 * Insert an element after the current item.
+	 */
+	@Override
+	public void insertAfter(final T itm) {
+		if (pos == backing.size() - 1) {
+			backing.add(itm);
+		} else {
+			backing.add(pos + 1, itm);
+		}
+	}
+
+	/**
+	 * Remove the current element.
+	 *
+	 * Also moves the cursor back one step if possible to maintain relative
+	 * position.
+	 *
+	 * @return The removed item.
+	 */
+	@Override
+	public T remove() {
+		final T res = backing.remove(pos);
+		if (pos != 0) {
+			pos -= 1;
+		}
+		return res;
+	}
+
+	/**
+	 * Move the cursor to the left-most position.
+	 */
+	@Override
+	public void first() {
+		pos = 0;
+	}
+
+	/**
+	 * Move the cursor the right-most position.
+	 */
+	@Override
+	public void last() {
+		pos = backing.size() - 1;
+	}
+
+	/**
+	 * Move the cursor one space left.
+	 *
+	 * The cursor can't go past zero.
+	 *
+	 * @return True if the cursor was moved left.
+	 */
+	@Override
+	public boolean left() {
+		return left(1);
+	}
+
+	/**
+	 * Move the cursor the specified amount left.
+	 *
+	 * The cursor can't go past zero. Attempts to move the cursor by amounts
+	 * that would exceed zero don't move the cursor at all.
+	 *
+	 * @param amt
+	 *                The amount to attempt to move the cursor left.
+	 *
+	 * @return True if the cursor was moved left.
+	 */
+	@Override
+	public boolean left(final int amt) {
+		if (pos - amt < 0) return false;
+
+		pos -= amt;
+		return true;
+	}
+
+	/**
+	 * Move the cursor one space right.
+	 *
+	 * Moving the cursor right will auto-extend the tape if that is enabled.
+	 *
+	 * @return Whether the cursor was moved right.
+	 */
+	@Override
+	public boolean right() {
+		return right(1);
+	}
+
+	/**
+	 * Move the cursor the specified amount right.
+	 *
+	 * Moving the cursor right will auto-extend the tape if that is enabled.
+	 *
+	 * @param amt
+	 *                The amount to move the cursor right by.
+	 *
+	 * @return Whether the cursor was moved right.
+	 */
+	@Override
+	public boolean right(final int amt) {
+		if (pos + amt >= backing.size() - 1) {
+			if (autoExtend) {
+				while (pos + amt >= backing.size() - 1) {
+					backing.add(null);
+				}
+			} else return false;
+		}
+
+		pos += amt;
+		return true;
+	}
+
+	@Override
+	public boolean isDoubleSided() {
+		return false;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+
+		int result = 1;
+		result = prime * result + (backing == null ? 0 : backing.hashCode());
+
+		return result;
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj) return true;
+		if (obj == null) return false;
+		if (!(obj instanceof SingleTape<?>)) return false;
+
+		final SingleTape<?> other = (SingleTape<?>) obj;
+
+		if (backing == null) {
+			if (other.backing != null) return false;
+		} else if (!backing.equals(other.backing)) return false;
+
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return String.format("SingleTape [backing=%s, pos=%s, autoExtend=%s]", backing, pos, autoExtend);
+	}
+}