Specification

f(x):[g(x)->h(j(x))->i(x)]

Description

The black box composition pattern consists of a structured assembly of services and inter-related URI requests. The complex functional assembly is abstracted behind a single 'black-box' service interface. Higher order applications may integrate the abstracted service into a higher-order assembly which itself may then be abstracted behind a black-box interface. One of the essential properties of NetKernel's layered URI address space is that local complexity may always be abstracted and this process may be repeated at any level of granularity.

Usage

Generally the black-box interface is presented on the public interface of a module. However it can also be implemented as a rule for a mapper function.

This pattern is very frequently used. It is most often used for providing data processing services over an underlying data management layer.