TreeNode.java

package edu.northwestern.cbits.purple_robot_manager.models.trees;

import java.util.Map;

/**
 * Abstract class that defines the required elements of a tree node class.
 */

public abstract class TreeNode
{
    public static final String NAME = "name";

    private String _name = null;

    public TreeNode(String name)
    {
        this._name = name;
    }

    public String getName()
    {
        return this._name;
    }

    /**
     * Returns a prediction for the given state of the world as interpreted by
     * the model
     * 
     * @param features
     *            Features representing the current state of the world.
     * 
     * @return Map containing the prediction generated by the model as well as
     *         any associated metadata.
     * 
     * @throws TreeNodeException
     *             Thrown if an error occurs evaluating the model. Refer to the
     *             exception's message for details.
     */

    public abstract Map<String, Object> fetchPrediction(Map<String, Object> features) throws TreeNodeException;

    /**
     * Encapsulates tree-related exceptions.
     */

    public static class TreeNodeException extends Exception
    {
        public TreeNodeException(String message)
        {
            super(message);
        }

        private static final long serialVersionUID = 3671610661977748070L;
    }

    /**
     * Returns a nested presentation of the tree node and any descendants (if
     * applicable.
     * 
     * @param indent
     *            Number of levels to indent the tree. 1 level corresponds to 2
     *            spaces.
     * 
     * @return String representation of the tree suitable for human
     *         interpretation.
     * 
     * @throws TreeNodeException
     *             Thrown on an error encountered evaluating the tree.
     */

    public abstract String toString(int indent) throws TreeNodeException;

    /**
     * Equivalent to calling toString(0).
     * 
     * @see java.lang.Object#toString()
     */

    public String toString()
    {
        try
        {
            return this.toString(0);
        }
        catch (TreeNodeException e)
        {
            throw new RuntimeException(e);
        }
    }
}