In programs written in lazy functional languages such as for example Clean and Haskell, the programmer can choose freely whether particular subexpressions will be evaluated lazily (the default) or strictly (must be specified explicitly). It is widely known that this choice affects program behavior, resource consumption and semantics in several ways. However, not much experience is available abo...

We extend an existing first-order typing system for strictness analysis to the fully higher-order case, covering both the derivation system and the inference algorithm. The resulting strictness typing system has expressive capabilities far beyond that of traditional strictness analysis systems. This extension is developed with the explicit aim of formally proving soundness of higher-order stric...

This paper proves correctness of Nöcker’s method of strictness analysis, implemented for Clean, which is an effective way for strictness analysis in lazy functional languages based on their operational semantics. We improve upon the work of Clark, Hankin and Hunt, which addresses correctness of the abstract reduction rules. Our method also addresses the cycle detection rules, which are the main...

This report deals with strictness types, a way of recording whether a function needs its argument(s) or not. We shall present an inference system for assigning strictness types to expressions and subsequently we transform this system into an algorithm capable of annotating expressions with strictness types. We give an example of a transformation which can be optimized by means of these annotati...

We deene an inference system for modular strictness analysis of functional programs by extending a conjunctive strictness logic with polymorphic and conditional properties. This extended set of properties is used to deene a syntax-directed, polymorphic strictness analysis based on polymorphic recur-sion whose soundness is established via a translation from the polymorphic system into the conjun...