Fixed function argument ordering and default parameter type for addFunction

Updated unit tests
Fixed docs

2 files changed, 2 insertions, 2 deletions

diff --git a/src/NXP/Classes/Token/TokenFunction.php b/src/NXP/Classes/Token/TokenFunction.php
index b2866c3..d61bb5d 100644
--- a/src/NXP/Classes/Token/TokenFunction.php
+++ b/src/NXP/Classes/Token/TokenFunction.php
@@ -32,7 +32,7 @@ class TokenFunction extends AbstractContainerToken implements InterfaceFunction
         $args = [];
         list($places, $function) = $this->value;
         for ($i = 0; $i < $places; $i++) {
-            array_push($args, array_pop($stack)->getValue());
+            $args[] = array_shift($stack)->getValue();
         }
         $result = call_user_func_array($function, $args);
 
diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index 29c6a64..6325d35 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -174,7 +174,7 @@ class MathExecutor
      * @return MathExecutor
      * @throws \ReflectionException
      */
-    public function addFunction($name, $function = null, $places = 1)
+    public function addFunction($name, $function = null, $places = null)
     {
         $this->tokenFactory->addFunction($name, $function, $places);