first commit

class/class.DecimalConstants.php

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+<?php
+
+/**
+ * git statu class that holds many important numeric constants.
+ *
+ * @author Andreu Correa Casablanca <castarco@litipk.com>
+ */
+final class DecimalConstants
+{
+    private static $ZERO;
+    private static $ONE;
+    private static $NEGATIVE_ONE;
+    private static $HUNDRED;
+
+    private static $PI;
+    private static $EulerMascheroni;
+
+    private static $GoldenRatio;
+
+    private static $LightSpeed;
+
+    /**
+     * Private constructor.
+     */
+    private function __construct()
+    {
+    }
+
+    /**
+     * Private clone method.
+     */
+    private function __clone()
+    {
+    }
+
+    public static function zero()
+    {
+        if (self::$ZERO === null) {
+            self::$ZERO = Decimal::fromInteger(0);
+        }
+
+        return self::$ZERO;
+    }
+
+    public static function one()
+    {
+        if (self::$ONE === null) {
+            self::$ONE = Decimal::fromInteger(1);
+        }
+
+        return self::$ONE;
+    }
+
+    public static function negativeOne()
+    {
+        if (self::$NEGATIVE_ONE === null) {
+            self::$NEGATIVE_ONE = Decimal::fromInteger(-1);
+        }
+
+        return self::$NEGATIVE_ONE;
+    }
+
+    public static function hundred()
+    {
+        if (self::$HUNDRED === null) {
+            self::$HUNDRED = Decimal::fromInteger(100);
+        }
+
+        return self::$HUNDRED;
+    }
+
+    /**
+     * Returns the Pi number.
+     *
+     * @return Decimal
+     */
+    public static function pi()
+    {
+        if (self::$PI === null) {
+            self::$PI = Decimal::fromString(
+                '3.14159265358979323846264338327950'
+            );
+        }
+
+        return self::$PI;
+    }
+
+    /**
+     * Returns the Euler's E number.
+     *
+     * @param int $scale
+     *
+     * @return Decimal
+     */
+    public static function e($scale = 32)
+    {
+        if (!is_int($scale)) {
+            throw new InvalidArgumentTypeException(['integer'], gettype($scale));
+        }
+        if ($scale < 0) {
+            throw new \InvalidArgumentException('$scale must be positive.');
+        }
+
+        return self::$ONE->exp($scale);
+    }
+
+    /**
+     * Returns the Euler-Mascheroni constant.
+     *
+     * @return Decimal
+     */
+    public static function eulerMascheroni()
+    {
+        if (self::$EulerMascheroni === null) {
+            self::$EulerMascheroni = Decimal::fromString(
+                '0.57721566490153286060651209008240'
+            );
+        }
+
+        return self::$EulerMascheroni;
+    }
+
+    /**
+     * Returns the Golden Ration, also named Phi.
+     *
+     * @return Decimal
+     */
+    public static function goldenRatio()
+    {
+        if (self::$GoldenRatio === null) {
+            self::$GoldenRatio = Decimal::fromString(
+                '1.61803398874989484820458683436564'
+            );
+        }
+
+        return self::$GoldenRatio;
+    }
+
+    /**
+     * Returns the Light of Speed measured in meters / second.
+     *
+     * @return Decimal
+     */
+    public static function lightSpeed()
+    {
+        if (self::$LightSpeed === null) {
+            self::$LightSpeed = Decimal::fromInteger(299792458);
+        }
+
+        return self::$LightSpeed;
+    }
+}