Predicting resource consumption of higher-order workflows

Abstract

We present a type and effect system for static analysis of programs written in a simplified version of iTasks. iTasks is a workflow specification language embedded in Clean, a general-purpose functional programming language. Given costs for basic tasks, our analysis calculates an upper bound of the total cost of a workflow. The analysis has to deal with the domain-specific features of iTasks, in particular parallel and sequential composition of tasks, as well as the general-purpose features of Clean, in particular let-polymorphism, higher-order functions, recursion and lazy evaluation. Costs are vectors of natural numbers where every element represents some resource, either consumable or reusable.