call: A nucleus for a web of open functions

In our recent work we envisioned a Web where functions, like Linked Data, can be openly published and available to all the users of any remote sparql endpoint. The resulting Web of Functions can be realized by introducing a call sparql extension that can invoke any remote function (custom third-party extensions) by only knowing its corresponding URI, while the implementation and the computational resources are made available by the function publisher. In this paper we demo our framework with a set of functions showing (1) advanced use of its higher-order expressivity power featuring, e.g., function composition of third-party functions, and (2) a possible bridge between hundreds of standard Web APIs and the Web of Functions. In our view these functions found an initial nucleus to which anyone can contribute within the decentralized Web of Functions, made available through call.