ColumnEqualTo.java

package com.github.lwhite1.tablesaw.filtering.columnbased;

import com.github.lwhite1.tablesaw.api.ColumnType;
import com.github.lwhite1.tablesaw.api.IntColumn;
import com.github.lwhite1.tablesaw.api.LongColumn;
import com.github.lwhite1.tablesaw.api.ShortColumn;
import com.github.lwhite1.tablesaw.api.Table;
import com.github.lwhite1.tablesaw.columns.Column;
import com.github.lwhite1.tablesaw.columns.ColumnReference;
import com.github.lwhite1.tablesaw.filtering.ColumnFilter;
import com.github.lwhite1.tablesaw.util.Selection;
import com.google.common.base.Preconditions;

/**
 *
 */
public class ColumnEqualTo extends ColumnFilter {

    private final ColumnReference otherColumn;

    public ColumnEqualTo(ColumnReference a, ColumnReference b) {
        super(a);
        otherColumn = b;
    }

    public Selection apply(Table relation) {

        Column column = relation.column(columnReference().getColumnName());
        Column other = relation.column(otherColumn.getColumnName());

        Preconditions.checkArgument(column.type() == other.type());

        if (column.type() == ColumnType.INTEGER)
            return apply((IntColumn) column, (IntColumn) other);

        if (column.type() == ColumnType.LONG_INT)
            return apply((LongColumn) column, (LongColumn) other);

        if (column.type() == ColumnType.SHORT_INT)
            return apply((ShortColumn) column, (ShortColumn) other);

        throw new UnsupportedOperationException("Not yet implemented for this column type");
    }

    private static Selection apply(IntColumn column1, IntColumn column2) {
        return column1.isEqualTo(column2);
    }

    private static Selection apply(ShortColumn column1, ShortColumn column2) {
        return column1.isEqualTo(column2);
    }

    private static Selection apply(LongColumn column1, LongColumn column2) {
        return column1.isEqualTo(column2);
    }
}