built-in function

hello ,I like zephir.but I don't know the built-in function documentation . In php documentation ,I can find such as curl_init,echo,ereg ,asn so on. does zephir has some build-in function like that or we can use the same function name like php‘s build-in function in zephir

You can call all functions available in PHP. Some functions are specially optimized (like str_replace, echo, ..) which therefore provide higher performance.

and how can I ues curl in zephir ,I use it in zephir but it has a lots of errors