Fixed function parameter order

Corrected $places default value for addFunction to match TokenFactory
Added function order test and put expected order first in assertEquals
If else blocks in calculator
Updated docs

3 files changed, 7 insertions, 11 deletions

diff --git a/src/NXP/Classes/Calculator.php b/src/NXP/Classes/Calculator.php
index 1ceac84..62dbc17 100644
--- a/src/NXP/Classes/Calculator.php
+++ b/src/NXP/Classes/Calculator.php
@@ -38,22 +38,18 @@ class Calculator
         foreach ($tokens as $token) {
             if ($token instanceof TokenNumber) {
                 array_push($stack, $token);
-            }
-            if ($token instanceof TokenStringDoubleQuoted) {
+            } else if ($token instanceof TokenStringDoubleQuoted) {
                 array_push($stack, $token);
-            }
-            if ($token instanceof TokenStringSingleQuoted) {
+            } else if ($token instanceof TokenStringSingleQuoted) {
                 array_push($stack, $token);
-            }
-            if ($token instanceof TokenVariable) {
+            } else if ($token instanceof TokenVariable) {
                 $variable = $token->getValue();
                 if (!array_key_exists($variable, $variables)) {
                     throw new UnknownVariableException($variable);
                 }
                 $value = $variables[$variable];
                 array_push($stack, new TokenNumber($value));
-            }
-            if ($token instanceof InterfaceOperator || $token instanceof TokenFunction) {
+            } else if ($token instanceof InterfaceOperator || $token instanceof TokenFunction) {
                 array_push($stack, $token->execute($stack));
             }
         }
diff --git a/src/NXP/Classes/Token/TokenFunction.php b/src/NXP/Classes/Token/TokenFunction.php
index b2866c3..04eae30 100644
--- a/src/NXP/Classes/Token/TokenFunction.php
+++ b/src/NXP/Classes/Token/TokenFunction.php
@@ -32,9 +32,9 @@ 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());
+            $args[] = array_pop($stack)->getValue();
         }
-        $result = call_user_func_array($function, $args);
+        $result = call_user_func_array($function, array_reverse($args));
 
         return new TokenNumber($result);
     }
diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index 29c6a64..6325d35 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -174,7 +174,7 @@ class MathExecutor
      * @return MathExecutor
      * @throws \ReflectionException
      */
-    public function addFunction($name, $function = null, $places = 1)
+    public function addFunction($name, $function = null, $places = null)
     {
         $this->tokenFactory->addFunction($name, $function, $places);