4 files changed, 53 insertions, 21 deletions

diff --git a/src/NXP/Classes/Calculator.php b/src/NXP/Classes/Calculator.php
index 10adc24..6b63503 100644
--- a/src/NXP/Classes/Calculator.php
+++ b/src/NXP/Classes/Calculator.php
@@ -74,7 +74,7 @@ class Calculator
                 if (! \array_key_exists($token->value, $this->functions)) {
                     throw new UnknownFunctionException($token->value);
                 }
-                $stack[] = $this->functions[$token->value]->execute($stack);
+                $stack[] = $this->functions[$token->value]->execute($stack, $token->paramCount);
             } elseif (Token::Operator === $token->type) {
                 if (! \array_key_exists($token->value, $this->operators)) {
                     throw new UnknownOperatorException($token->value);
diff --git a/src/NXP/Classes/CustomFunction.php b/src/NXP/Classes/CustomFunction.php
index 843cf82..1ebdd2c 100644
--- a/src/NXP/Classes/CustomFunction.php
+++ b/src/NXP/Classes/CustomFunction.php
@@ -2,6 +2,7 @@
 
 namespace NXP\Classes;
 
+use NXP\Exception\IncorrectFunctionParameterException;
 use NXP\Exception\IncorrectNumberOfFunctionParametersException;
 use ReflectionException;
 use ReflectionFunction;
@@ -15,41 +16,48 @@ class CustomFunction
      */
     public $function;
 
-    public int $places = 0;
+    private ReflectionFunction $reflectionFunction;
 
     /**
      * CustomFunction constructor.
      *
      * @throws ReflectionException
-     * @throws IncorrectNumberOfFunctionParametersException
      */
-    public function __construct(string $name, callable $function, ?int $places = null)
+    public function __construct(string $name, callable $function)
     {
         $this->name = $name;
         $this->function = $function;
+        $this->reflectionFunction = new ReflectionFunction($function);
 
-        if (null === $places) {
-            $reflection = new ReflectionFunction($function);
-            $this->places = $reflection->getNumberOfParameters();
-        } else {
-            $this->places = $places;
-        }
     }
 
     /**
      * @param array<Token> $stack
      *
-     * @throws IncorrectNumberOfFunctionParametersException
+     * @throws IncorrectNumberOfFunctionParametersException|IncorrectFunctionParameterException
      */
-    public function execute(array &$stack) : Token
+    public function execute(array &$stack, int $paramCountInStack) : Token
     {
-        if (\count($stack) < $this->places) {
+        if ($paramCountInStack < $this->reflectionFunction->getNumberOfRequiredParameters()) {
             throw new IncorrectNumberOfFunctionParametersException($this->name);
         }
         $args = [];
 
-        for ($i = 0; $i < $this->places; $i++) {
-            \array_unshift($args, \array_pop($stack)->value);
+        if ($paramCountInStack > 0) {
+            $reflectionParameters = $this->reflectionFunction->getParameters();
+
+            for ($i = 0; $i < $paramCountInStack; $i++) {
+                $value = \array_pop($stack)->value;
+                $valueType = \gettype($value);
+                $reflectionParameter = $reflectionParameters[\min(\count($reflectionParameters) - 1, $i)];
+                //TODO to support type check for union types (php >= 8.0) and intersection types (php >= 8.1), we should increase min php level in composer.json
+                // For now, only support basic types. @see testFunctionParameterTypes
+                if ($reflectionParameter->hasType() && $reflectionParameter->getType()->getName() !== $valueType){
+                    throw new IncorrectFunctionParameterException();
+                }
+
+                \array_unshift($args, $value);
+            }
         }
 
         $result = \call_user_func_array($this->function, $args);
diff --git a/src/NXP/Classes/Token.php b/src/NXP/Classes/Token.php
index e75b17e..7532e77 100644
--- a/src/NXP/Classes/Token.php
+++ b/src/NXP/Classes/Token.php
@@ -28,6 +28,8 @@ class Token
 
     public ?string $name;
 
+    public ?int $paramCount = null;//to store function parameter count in stack
+
     /**
      * Token constructor.
      *
diff --git a/src/NXP/Classes/Tokenizer.php b/src/NXP/Classes/Tokenizer.php
index 32404a2..23e1cc9 100644
--- a/src/NXP/Classes/Tokenizer.php
+++ b/src/NXP/Classes/Tokenizer.php
@@ -20,7 +20,7 @@ use SplStack;
  */
 class Tokenizer
 {
-    /** @var array<Token>  */
+    /** @var array<Token> */
     public array $tokens = [];
 
     private string $input = '';
@@ -31,7 +31,7 @@ class Tokenizer
 
     private bool $allowNegative = true;
 
-    /** @var array<Operator>  */
+    /** @var array<Operator> */
     private array $operators = [];
 
     private bool $inSingleQuotedString = false;
@@ -99,8 +99,8 @@ class Tokenizer
 
                         break;
                     }
-                    // no break
-                    // Intentionally fall through
+                // no break
+                // Intentionally fall through
                 case $this->isAlpha($ch):
                     if (\strlen($this->numberBuffer)) {
                         $this->emptyNumberBufferAsLiteral();
@@ -196,8 +196,8 @@ class Tokenizer
     }
 
     /**
-     * @throws IncorrectBracketsException
      * @throws UnknownOperatorException
+     * @throws IncorrectBracketsException
      * @return Token[] Array of tokens in revers polish notation
      */
     public function buildReversePolishNotation() : array
@@ -205,6 +205,10 @@ class Tokenizer
         $tokens = [];
         /** @var SplStack<Token> $stack */
         $stack = new SplStack();
+        /**
+         * @var SplStack<int> $paramCounter
+         */
+        $paramCounter = new SplStack();
 
         foreach ($this->tokens as $token) {
             switch ($token->type) {
@@ -213,9 +217,21 @@ class Tokenizer
                 case Token::String:
                     $tokens[] = $token;
 
+                    if ($paramCounter->count() > 0 && 0 === $paramCounter->top()) {
+                        $paramCounter->push($paramCounter->pop() + 1);
+                    }
+
                     break;
 
                 case Token::Function:
+                    if ($paramCounter->count() > 0 && 0 === $paramCounter->top()) {
+                        $paramCounter->push($paramCounter->pop() + 1);
+                    }
+                    $stack->push($token);
+                    $paramCounter->push(0);
+
+                    break;
+
                 case Token::LeftParenthesis:
                     $stack->push($token);
 
@@ -228,6 +244,7 @@ class Tokenizer
                         }
                         $tokens[] = $stack->pop();
                     }
+                    $paramCounter->push($paramCounter->pop() + 1);
 
                     break;
 
@@ -270,7 +287,12 @@ class Tokenizer
                     }
 
                     if ($stack->count() > 0 && Token::Function == $stack->top()->type) {
-                        $tokens[] = $stack->pop();
+                        /**
+                         * @var Token $f
+                         */
+                        $f = $stack->pop();
+                        $f->paramCount = $paramCounter->pop();
+                        $tokens[] = $f;
                     }
 
                     break;