The talk has been accepted at the eighth RacketCon held from 2018-09-29 to 2018-09-30 in St. Louis, Missouri.

Petri Net Flavored Places: An Advanced Transition System for Distributed Computing in Racket

Places provide a way to specify parallel and distributed computation in Racket. Using places we can set up independent services that communicate via channels. Often state machines are used in this setting to model session state, resource allocation, or service start order. However, plain state machines often suffer from the explosion of the state space as soon as multiple state variables appear in combination. Also some applications have only an infinite representation, if modeled as a state machine.

In this talk, we address these challenges by introducing pnet, a Racket library that allows to define Racket places as Petri nets. Petri nets are a class of transition systems representing state as tokens produced and consumed by transitions. We consider several examples for Petri nets as Racket places such as a worker pool and consider the possibility of driving the pnet library from a tailor-made DSL or using it to construct distributed programming languages.