IlyaM, why should you care how long the library code is? What matters is whether the client code is more concise, or more readable, or allows users to be more expressive and efficient.

I have no idea which API is better in that regard, I'm only commenting on your rather misguided measure of how good an API is based on its implementation details. If the two provide exactly equivalent features with neither having any advantage for the user, then it makes sense to question the benefit of the additional complexity in the implementation.