Support Math Function

.gitignore

@@ -1 +1,6 @@
-vendor
+vendor
+
+# Netbeans
+/nbproject/private/
+project.properties
+project.xml

lib/PHPMathParser/Expressions/MathFunction.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * The PHP Math Parser library
+ *
+ * @author     Mohamed BOUDAOUI (motionSeed) <dev@motionseed.com>
+ * @copyright  2017 The Authors
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    Build @@version@@
+ */
+namespace PHPMathParser\Expressions;
+
+use PHPMathParser\Stack;
+
+class MathFunction extends Operator
+{
+    protected $precedence = 10;
+
+    protected static $functions = [
+        'ABS',
+        'COS', 'COSH', 'SIN', 'SINH', 'TAN', 'TANH', 'ACOS', 'ACOSH', 'ASIN', 'ASINH', 'ATAN', 'ATAN2', 'ATANH',
+        'DEG2GRAD', 'RAD2DEG', 'PI',
+        'CEIL', 'FLOOR', 'ROUND', 'SQRT', 'LOG10'
+    ];
+
+    public static function isFunction($value)
+    {
+        return in_array($value, self::$functions);
+    }
+
+    public function operate(Stack $stack)
+    {
+        $value = $stack->pop()->operate($stack);
+
+        $function = strtolower($this->value);
+
+        $result = new Number($function($value));
+
+        return $result->operate($stack);
+    }
+}

lib/PHPMathParser/TerminalExpression.php

@@ -18,6 +18,7 @@
 use PHPMathParser\Expressions\Power;
 use PHPMathParser\Expressions\Subtraction;
 use PHPMathParser\Expressions\Unary;
+use PHPMathParser\Expressions\MathFunction;
 
 abstract class TerminalExpression
 {
@@ -48,6 +49,8 @@ public static function factory($value)
             return new Parenthesis($value);
         } elseif ($value == '^') {
             return new Power($value);
+        } elseif (MathFunction::isFunction($value)) {
+            return new MathFunction($value);
         }
         throw new \Exception('Undefined Value ' . $value);
     }

test.php

@@ -98,4 +98,25 @@
 	$math->registerVariable('a', -5.5);
 	$answer = $math->evaluate('($a + $a) * 4');
 	var_dump($answer);echo "<br /><br />";
-	// float(-44)
+	// float(-44)
+
+    // TEST added by motionSeed 
+    $math->registerVariable('a', 5);
+	$answer = $math->evaluate('10 + CEIL($a / 4)');
+	var_dump($answer);echo "<br /><br />";
+	// int(12)
+
+    $math->registerVariable('a', 5);
+	$answer = $math->evaluate('10 + FLOOR($a / 4)');
+	var_dump($answer);echo "<br /><br />";
+	// int(11)
+
+    $math->registerVariable('a', 9);
+	$answer = $math->evaluate('10 + SQRT($a)');
+	var_dump($answer);echo "<br /><br />";
+	// int(13)
+
+    $math->registerVariable('a', 10);
+	$answer = $math->evaluate('10 + CEIL(SQRT($a))');
+	var_dump($answer);echo "<br /><br />";
+	// int(14)