code: public function apply(Scope $scope, GenericList $arguments) {
  		$nargs = count($arguments);
  		if ($nargs == 0) throw new \BadFunctionCallException("ArrayWalk: No target specified.");
  		elseif ($nargs == 1) throw new \BadFunctionCallException("ArrayWalk: No callback specified.");
  		$target = $arguments[0];
  		if (!($target instanceof Symbol))
  			throw new \InvalidArgumentException(sprintf("ArrayWalk: Expected symbol as first argument but %s was found instead.", substr(strtolower(strstr(get_class($arguments[0]), '\\')), 1)));
  		$ref = $target->symbol;
  		
  		if (is_array($scope->symbols[$ref]) || $scope->symbols[$ref] instanceof \ArrayObject) {
  			$op = $arguments[1]->evaluate($scope);
  			if (is_callable($op)) return array_walk($scope->symbols[$ref], $op, $nargs > 2 ? $arguments[2]->evaluate($scope) : null);
  			throw new \InvalidArgumentException("ArrayWalk: Expected callable as second argument.");
  		}
  		
  		throw new \InvalidArgumentException(sprintf("ArrayWalk: Expected array as first argument but %s was found instead.", gettype($scope->symbols[$ref])));
  	}
docs: Applies the user-defined callback function to each element of an array.
  Usage: (Array::walk _arr _callback)
  Returns: boolean
  (non-PHPdoc)
  @see \eMacros\Applicable::apply()