Call Arity. (June 2018)

• Record Type: Journal Article
• Authors: Breitner, Joachim
• Is Part Of: Computer languages, systems & structures. Volume 52(2017)
• Page Start: 65
• Page End: 91
• Publication Date: 2018-06
• Subjects: Programming languages (Electronic computers) -- Periodicals; Computer networks -- Periodicals; Computer architecture -- Periodicals; Computer systems -- Periodicals; Langage de programmation; Réseau d'ordinateurs; Architecture d'ordinateur; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 005.13
• DOI: 10.1016/j.cl.2017.03.001
• Languages: English
• ISSNs: 1477-8424

Abstract

Highlights: A new arity analysis, precise in the precense of recursion, due to a novel cardinality analysis. Solves a long-standing open problem with list fusion. Program performance benchmark results that demonstrate its usefulness. Notes on the implementation of Call Arity in the Haskell compiler GHC. Abstract: Higher order combinators in functional programming languages can lead to code that would be considerably more efficient if some functions' definitions were eta-expanded. Previous analyses were not always precise enough to allow that. In particular, this has preventedfoldl from efficiently taking part in list fusion. Call Arity is an analysis that eta-expands functions according to how they are used. By virtue of using a new cardinality analysis based on the notion of co-call graphs, it is sufficiently precise even in the presence of recursion, and its inclusion in the Haskell compiler GHC now enables the fusion offoldl -based combinators.