getCallable example

public function compile(Compiler $compiler): void
    {
        $name = $this->getNode('filter')->getAttribute('value');
        $filter = $compiler->getEnvironment()->getFilter($name);

        $this->setAttribute('name', $name);
        $this->setAttribute('type', 'filter');
        $this->setAttribute('needs_environment', $filter->needsEnvironment());
        $this->setAttribute('needs_context', $filter->needsContext());
        $this->setAttribute('arguments', $filter->getArguments());
        $this->setAttribute('callable', $filter->getCallable());
        $this->setAttribute('is_variadic', $filter->isVariadic());

        $this->compileCallable($compiler);
    }
}

parent::__construct($nodes, ['name' => $name], $lineno);
    }

    public function compile(Compiler $compiler): void
    {
        $name = $this->getAttribute('name');
        $test = $compiler->getEnvironment()->getTest($name);

        $this->setAttribute('name', $name);
        $this->setAttribute('type', 'test');
        $this->setAttribute('arguments', $test->getArguments());
        $this->setAttribute('callable', $test->getCallable());
        $this->setAttribute('is_variadic', $test->isVariadic());

        $this->compileCallable($compiler);
    }
}

    private function getMetadata(string $type, mixed $entity): mixed
    {
        if ('globals' === $type) {
            return $entity;
        }
        if ('tests' === $type) {
            return null;
        }
        if ('functions' === $type || 'filters' === $type) {
            $cb = $entity->getCallable();
            if (null === $cb) {
                return null;
            }
            if (\is_array($cb)) {
                if (!method_exists($cb[0], $cb[1])) {
                    return null;
                }
                $refl = new \ReflectionMethod($cb[0], $cb[1]);
            } elseif (\is_object($cb) && method_exists($cb, '__invoke')) {
                $refl = new \ReflectionMethod($cb, '__invoke');
            } elseif (\function_exists($cb)) {
                

public function compile(Compiler $compiler)
    {
        $name = $this->getAttribute('name');
        $function = $compiler->getEnvironment()->getFunction($name);

        $this->setAttribute('name', $name);
        $this->setAttribute('type', 'function');
        $this->setAttribute('needs_environment', $function->needsEnvironment());
        $this->setAttribute('needs_context', $function->needsContext());
        $this->setAttribute('arguments', $function->getArguments());
        $callable = $function->getCallable();
        if ('constant' === $name && $this->getAttribute('is_defined_test')) {
            $callable = 'twig_constant_is_defined';
        }
        $this->setAttribute('callable', $callable);
        $this->setAttribute('is_variadic', $function->isVariadic());

        $this->compileCallable($compiler);
    }
}