Abstract
In many domains, classes have highly regular internal structure. For example, so-called business objects often contain boilerplate code for mapping database fields to class members. The boilerplate code must be repeated per-field for every class, because existing mechanisms for constructing classes do not provide a way to capture and reuse such member-level structure. As a result, programmers often resort to ad hoc code generation. This paper presents a lightweight mechanism for specifying and reusing member-level structure in Java programs. The proposal is based on a modest extension to traits that we have termed trait-based metaprogramming. Although the semantics of the mechanism are straightforward, its type theory is difficult to reconcile with nominal subtyping. We achieve reconciliation by introducing a hybrid structural/nominal type system that extends Java’s type system. The paper includes a formal calculus defined by translation to Featherweight Generic Java.
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Reppy, J., Turon, A. (2007). Metaprogramming with Traits. In: Ernst, E. (eds) ECOOP 2007 – Object-Oriented Programming. ECOOP 2007. Lecture Notes in Computer Science, vol 4609. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-73589-2_18
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DOI: https://doi.org/10.1007/978-3-540-73589-2_18
Publisher Name: Springer, Berlin, Heidelberg
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