Start work on breaking down some of the Financial Excel functions

src/PhpSpreadsheet/Calculation/Calculation.php

@@ -875,12 +875,12 @@ class Calculation
         ],
         'DOLLARDE' => [
             'category' => Category::CATEGORY_FINANCIAL,
-            'functionCall' => [Financial::class, 'DOLLARDE'],
+            'functionCall' => [Financial\Dollar::class, 'decimal'],
             'argumentCount' => '2',
         ],
         'DOLLARFR' => [
             'category' => Category::CATEGORY_FINANCIAL,
-            'functionCall' => [Financial::class, 'DOLLARFR'],
+            'functionCall' => [Financial\Dollar::class, 'fractional'],
             'argumentCount' => '2',
         ],
         'DPRODUCT' => [

src/PhpSpreadsheet/Calculation/Financial.php

@@ -997,30 +997,18 @@ public static function DISC($settlement, $maturity, $price, $redemption, $basis
      * Excel Function:
      *        DOLLARDE(fractional_dollar,fraction)
      *
+     * @Deprecated 1.18.0
+     *
+     * @see Use the decimal() method in the Financial\Dollar class instead
+     *
      * @param float $fractional_dollar Fractional Dollar
      * @param int $fraction Fraction
      *
      * @return float|string
      */
     public static function DOLLARDE($fractional_dollar = null, $fraction = 0)
     {
-        $fractional_dollar = Functions::flattenSingleValue($fractional_dollar);
-        $fraction = (int) Functions::flattenSingleValue($fraction);
-
-        // Validate parameters
-        if ($fractional_dollar === null || $fraction < 0) {
-            return Functions::NAN();
-        }
-        if ($fraction == 0) {
-            return Functions::DIV0();
-        }
-
-        $dollars = floor($fractional_dollar);
-        $cents = fmod($fractional_dollar, 1);
-        $cents /= $fraction;
-        $cents *= 10 ** ceil(log10($fraction));
-
-        return $dollars + $cents;
+        return Financial\Dollar::decimal($fractional_dollar, $fraction);
     }
 
     /**
@@ -1033,30 +1021,18 @@ public static function DOLLARDE($fractional_dollar = null, $fraction = 0)
      * Excel Function:
      *        DOLLARFR(decimal_dollar,fraction)
      *
+     * @Deprecated 1.18.0
+     *
+     * @see Use the fractional() method in the Financial\Dollar class instead
+     *
      * @param float $decimal_dollar Decimal Dollar
      * @param int $fraction Fraction
      *
      * @return float|string
      */
     public static function DOLLARFR($decimal_dollar = null, $fraction = 0)
     {
-        $decimal_dollar = Functions::flattenSingleValue($decimal_dollar);
-        $fraction = (int) Functions::flattenSingleValue($fraction);
-
-        // Validate parameters
-        if ($decimal_dollar === null || $fraction < 0) {
-            return Functions::NAN();
-        }
-        if ($fraction == 0) {
-            return Functions::DIV0();
-        }
-
-        $dollars = floor($decimal_dollar);
-        $cents = fmod($decimal_dollar, 1);
-        $cents *= $fraction;
-        $cents *= 10 ** (-ceil(log10($fraction)));
-
-        return $dollars + $cents;
+        return Financial\Dollar::fractional($decimal_dollar, $fraction);
     }
 
     /**

src/PhpSpreadsheet/Calculation/Financial/Dollar.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheet\Calculation\Financial;
+
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+
+class Dollar
+{
+    /**
+     * DOLLARDE.
+     *
+     * Converts a dollar price expressed as an integer part and a fraction
+     *        part into a dollar price expressed as a decimal number.
+     * Fractional dollar numbers are sometimes used for security prices.
+     *
+     * Excel Function:
+     *        DOLLARDE(fractional_dollar,fraction)
+     *
+     * @param float $fractionalDollar Fractional Dollar
+     * @param int $fraction Fraction
+     *
+     * @return float|string
+     */
+    public static function decimal($fractionalDollar = null, $fraction = 0)
+    {
+        $fractionalDollar = Functions::flattenSingleValue($fractionalDollar);
+        $fraction = (int) Functions::flattenSingleValue($fraction);
+
+        // Validate parameters
+        if ($fractionalDollar === null || $fraction < 0) {
+            return Functions::NAN();
+        }
+        if ($fraction == 0) {
+            return Functions::DIV0();
+        }
+
+        $dollars = floor($fractionalDollar);
+        $cents = fmod($fractionalDollar, 1);
+        $cents /= $fraction;
+        $cents *= 10 ** ceil(log10($fraction));
+
+        return $dollars + $cents;
+    }
+
+    /**
+     * DOLLARFR.
+     *
+     * Converts a dollar price expressed as a decimal number into a dollar price
+     *        expressed as a fraction.
+     * Fractional dollar numbers are sometimes used for security prices.
+     *
+     * Excel Function:
+     *        DOLLARFR(decimal_dollar,fraction)
+     *
+     * @param float $decimalDollar Decimal Dollar
+     * @param int $fraction Fraction
+     *
+     * @return float|string
+     */
+    public static function fractional($decimalDollar = null, $fraction = 0)
+    {
+        $decimalDollar = Functions::flattenSingleValue($decimalDollar);
+        $fraction = (int) Functions::flattenSingleValue($fraction);
+
+        // Validate parameters
+        if ($decimalDollar === null || $fraction < 0) {
+            return Functions::NAN();
+        }
+        if ($fraction == 0) {
+            return Functions::DIV0();
+        }
+
+        $dollars = floor($decimalDollar);
+        $cents = fmod($decimalDollar, 1);
+        $cents *= $fraction;
+        $cents *= 10 ** (-ceil(log10($fraction)));
+
+        return $dollars + $cents;
+    }
+}