2.16.3 Rationale

This SRFI defines an interface for sources of random bits computed by a pseudo random number generator. The interface provides range–limited integer and real numbers. It allows accessing the state of the underlying generator. Moreover, it is possible to obtain a large number of independent generators and to invoke a mild form of true randomization.

The design aims at sufficient flexibility to cover the usage patterns of many applications as diverse as discrete structures, numerical simulations, and cryptographic protocols. At the same time, the interface aims at simplicity, which is important for occasional use. As there is no “one size fits all” random number generator, the design necessarily represents some form of compromise between the needs of the various applications.

Although strictly speaking not part of the specification, the emphasis of this proposal is on high quality random numbers and on high performance. As the state of the art in pseudo random number generators is still advancing considerably, the choice of method for the reference implementation should essentially be considered preliminary.