VTable.java

/**
 * Copyright (C) 2010-14 diirt developers. See COPYRIGHT.TXT
 * All rights reserved. Use is subject to license terms. See LICENSE.TXT
 */
package org.diirt.vtype;

import java.util.List;
import org.diirt.util.array.ListNumber;

/**
 * A table. Tables are collections of columns, each of which is composed
 * of a String representing the name of the column and a list of a particular
 * type (all elements of the same column must be of the same type).
 *
 * @author carcassi
 */
public interface VTable extends VType {

    /**
     * The number of columns in the table.
     *
     * @return the number of columns
     */
    int getColumnCount();

    /**
     * The number of rows in the table.
     * <p>
     * Currently, it is not clear whether all columns actually have the same
     * number of rows, that is if all arrays have the same length. In the
     * case of variable row, this will return the maximum row count, that is
     * the length of the longest array/column.
     *
     * @return the number of rows
     */
    int getRowCount();

    /**
     * The type of the elements in the column. The column array will be
     * an array of the given type. For primitive types, this function will return
     * the TYPE class (such as {@link Double#TYPE}, while {@link #getColumnData(int) }
     * will return a {@link ListNumber}.
     *
     * @param column the column index
     * @return the type of this column
     */
    Class<?> getColumnType(int column);

    /**
     * The name of the given column.
     *
     * @param column the column index
     * @return the name of the column
     */
    String getColumnName(int column);

    /**
     * The data for the given column.
     * <p>
     * The data is going to be a {@link List} in case of objects
     * or a {@link ListNumber} in case of a numeric primitive.
     *
     * @param column the column index
     * @return the data of the column
     */
    Object getColumnData(int column);
}