Short note: Strict unwraps make worker/wrapper fusion totally correct

Abstract

Abstract The worker/wrapper transformation is a general way of changing the type of a recursive definition, usually applied with an eye to increasing algorithmic efficiency. This note identifies an infelicity in the program transformations presented by Gill & Hutton (The worker/wrapper transformation, J. Funct. Program ., vol. 19, 2009, pp. 227–251) and proposes a new totally correct worker/wrapper fusion rule.