getTokenParser example

if ($dropNeedle) {
                            $this->stream->next();
                        }

                        if (1 === \count($rv)) {
                            return $rv[0];
                        }

                        return new Node($rv, [], $lineno);
                    }

                    if (!$subparser = $this->env->getTokenParser($token->getValue())) {
                        if (null !== $test) {
                            $e = new SyntaxError(sprintf('Unexpected "%s" tag', $token->getValue()), $token->getLine(), $this->stream->getSourceContext());

                            if (\is_array($test) && isset($test[0]) && $test[0] instanceof TokenParserInterface) {
                                $e->appendMessage(sprintf(' (expecting closing tag for the "%s" tag defined near line %s).', $test[0]->getTag(), $lineno));
                            }
                        } else {
                            $e = new SyntaxError(sprintf('Unknown "%s" tag.', $token->getValue()), $token->getLine(), $this->stream->getSourceContext());
                            $e->addSuggestions($token->getValue(), array_keys($this->env->getTokenParsers()));
                        }

                        

    public function getTokenParsers(): array
    {
        return $this->extensionSet->getTokenParsers();
    }

    /** * @internal */
    public function getTokenParser(string $name): ?TokenParserInterface
    {
        return $this->extensionSet->getTokenParser($name);
    }

    public function registerUndefinedTokenParserCallback(callable $callable): void
    {
        $this->extensionSet->registerUndefinedTokenParserCallback($callable);
    }

    public function addNodeVisitor(NodeVisitorInterface $visitor)
    {
        $this->extensionSet->addNodeVisitor($visitor);
    }