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libraries/vendor/brick/math/src/RoundingMode.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Brick\Math;
+
+/**
+ * Specifies a rounding behavior for numerical operations capable of discarding precision.
+ *
+ * Each rounding mode indicates how the least significant returned digit of a rounded result
+ * is to be calculated. If fewer digits are returned than the digits needed to represent the
+ * exact numerical result, the discarded digits will be referred to as the discarded fraction
+ * regardless the digits' contribution to the value of the number. In other words, considered
+ * as a numerical value, the discarded fraction could have an absolute value greater than one.
+ */
+enum RoundingMode
+{
+    /**
+     * Asserts that the requested operation has an exact result, hence no rounding is necessary.
+     *
+     * If this rounding mode is specified on an operation that yields a result that
+     * cannot be represented at the requested scale, a RoundingNecessaryException is thrown.
+     */
+    case UNNECESSARY;
+
+    /**
+     * Rounds away from zero.
+     *
+     * Always increments the digit prior to a nonzero discarded fraction.
+     * Note that this rounding mode never decreases the magnitude of the calculated value.
+     */
+    case UP;
+
+    /**
+     * Rounds towards zero.
+     *
+     * Never increments the digit prior to a discarded fraction (i.e., truncates).
+     * Note that this rounding mode never increases the magnitude of the calculated value.
+     */
+    case DOWN;
+
+    /**
+     * Rounds towards positive infinity.
+     *
+     * If the result is positive, behaves as for UP; if negative, behaves as for DOWN.
+     * Note that this rounding mode never decreases the calculated value.
+     */
+    case CEILING;
+
+    /**
+     * Rounds towards negative infinity.
+     *
+     * If the result is positive, behave as for DOWN; if negative, behave as for UP.
+     * Note that this rounding mode never increases the calculated value.
+     */
+    case FLOOR;
+
+    /**
+     * Rounds towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.
+     *
+     * Behaves as for UP if the discarded fraction is >= 0.5; otherwise, behaves as for DOWN.
+     * Note that this is the rounding mode commonly taught at school.
+     */
+    case HALF_UP;
+
+    /**
+     * Rounds towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.
+     *
+     * Behaves as for UP if the discarded fraction is > 0.5; otherwise, behaves as for DOWN.
+     */
+    case HALF_DOWN;
+
+    /**
+     * Rounds towards "nearest neighbor" unless both neighbors are equidistant, in which case round towards positive infinity.
+     *
+     * If the result is positive, behaves as for HALF_UP; if negative, behaves as for HALF_DOWN.
+     */
+    case HALF_CEILING;
+
+    /**
+     * Rounds towards "nearest neighbor" unless both neighbors are equidistant, in which case round towards negative infinity.
+     *
+     * If the result is positive, behaves as for HALF_DOWN; if negative, behaves as for HALF_UP.
+     */
+    case HALF_FLOOR;
+
+    /**
+     * Rounds towards the "nearest neighbor" unless both neighbors are equidistant, in which case rounds towards the even neighbor.
+     *
+     * Behaves as for HALF_UP if the digit to the left of the discarded fraction is odd;
+     * behaves as for HALF_DOWN if it's even.
+     *
+     * Note that this is the rounding mode that statistically minimizes
+     * cumulative error when applied repeatedly over a sequence of calculations.
+     * It is sometimes known as "Banker's rounding", and is chiefly used in the USA.
+     */
+    case HALF_EVEN;
+}