Interface Decimal

core/src/main/java/io/questdb/std/Decimal.java:45–176

Common interface for all decimal types (Decimal64, Decimal128, Decimal256). This interface defines the core operations required for decimal parsing and manipulation. All decimal types in QuestDB implement this interface to provide consistent behavior across different precision levels. T

 * @see DecimalParser
 */
public interface Decimal {
    /**
     * Adds a specific digit multiplied by a power of ten to the current decimal value.
     * <p>
     * This method is used during decimal parsing to build up the value digit by digit.
     * It modifies the decimal in-place by adding (multiplier × 10^pow) to the current value.
     * </p>
     * <p>
     * Example: To add the digit 5 at position 10^2 (hundreds place):
     * <pre>
     * decimal.addPowerOfTenMultiple(2, 5);  // Adds 500 to the value
     * </pre>
     *
     * @param pow        the power of ten position (0 for ones, 1 for tens, 2 for hundreds, etc.)
     * @param multiplier the digit to add (0-9); 0 is a no-op for efficiency
     * @throws NumericException if the operation would cause overflow
     */
    void addPowerOfTenMultiple(int pow, int multiplier);

    /**
     * Returns the maximum precision (total number of significant digits) supported by this decimal type.
     * <p>
     * Precision limits vary by implementation:
     * <ul>
     * <li>Decimal64: 18 digits</li>
     * <li>Decimal128: 38 digits</li>
     * <li>Decimal256: 76 digits</li>
     * </ul>
     *
     * @return the maximum number of significant digits this type can represent
     */
    int getMaxPrecision();

    /**
     * Returns the maximum scale (number of digits after the decimal point) supported by this decimal type.
     * <p>
     * Scale limits vary by implementation:
     * <ul>
     * <li>Decimal64: 18</li>
     * <li>Decimal128: 38</li>
     * <li>Decimal256: 76</li>
     * </ul>
     *
     * @return the maximum number of decimal places this type can represent
     */
    int getMaxScale();

    /**
     * Returns true if this decimal represents the null value.
     */
    boolean isNull();

    /**
     * Negates this decimal value in-place, changing its sign.
     * <p>
     * If the decimal is positive, it becomes negative; if negative, it becomes positive.
     * Zero remains zero. Null values remain null.
     * <p>