External Uniqueness Is Unique Enough
نویسندگان
چکیده
External uniqueness is a surprising new way to add unique references to an OOPL. The idea is that an externally unique reference is the only reference into an aggregate from outside the aggregate. Internal references which do not escape the boundary of the aggregate are innocuous and therefore permitted. Based on ownership types, our proposal not only overcomes an abstraction problem from which existing uniqueness proposals suffer, it also enables many examples which are inherently not unique, such as a unique reference to a set of links in a doubly-linked list, without losing the benefits of uniqueness.
منابع مشابه
External Uniqueness
External uniqueness is a novel form of unique pointers that fit more natural with object-oriented programming. External uniqueness enforces the structural property that a unique pointer is a dominating node to the aggregate it references—there may be no other pointer from outside the aggregate to objects in it in the rest of the system. This paper completes previous work by the authors (Clarke ...
متن کاملCapabilities for External Uniqueness
Unique object references have many important applications in object-oriented programming. For instance, with su cient encapsulation properties they enable safe and e cient transfer of message objects between concurrent processes. However, it is a long-standing challenge to integrate unique references into practical object-oriented programming languages. This paper introduces a new approach to e...
متن کاملA Uniqueness Theorem of the Solution of an Inverse Spectral Problem
This paper is devoted to the proof of the unique solvability ofthe inverse problems for second-order differential operators withregular singularities. It is shown that the potential functioncan be determined from spectral data, also we prove a uniquenesstheorem in the inverse problem.
متن کاملNonlinear Fuzzy Volterra Integro-differential Equation of N-th Order: Analytic Solution and Existence and Uniqueness of Solution
This paper focuses on the fuzzy Volterra integro-differential equation of nth order of the second-kind with nonlinear fuzzy kernel and initial values. The derived integral equations are solvable, the solutions of which are unique under certain conditions. The existence and uniqueness of the solutions are investigated in a theorem and an upper boundary is found for solutions. Comparison of the e...
متن کاملA Uniqueness Criterion for the Signorini Problem with Coulomb Friction
The purpose of this paper is to study the solutions to the Signorini problem with Coulomb friction (the so-called Coulomb problem). Some optimal a priori estimates are given and a uniqueness criterion is exhibited. Recently, nonuniqueness examples have been presented in the continuous framework. It is proven, here, that if a solutions satisfies a certain hypothesis on the tangential displacemen...
متن کامل