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arXiv · 1407.3892

Verified Subtyping with Traits and Mixins

Asankhaya Sharma
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Abstract

Traits allow decomposing programs into smaller parts and mixins are a form of composition that resemble multiple inheritance. Unfortunately, in the presence of traits, programming languages like Scala give up on subtyping relation between objects. In this paper, we present a method to check subtyping between objects based on entailment in separation logic. We implement our method as a domain specific language in Scala and apply it on the Scala standard library. We have verified that 67% of mixins used in the Scala standard library do indeed conform to subtyping between the traits that are used to build them.

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Asankhaya Sharma. 2014-07-15. Verified Subtyping with Traits and Mixins. https://doi.org/10.4204/eptcs.156.8

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