The Challenge of Transforming State in the Adaptation Objects

摘要

When a provided interface and an expected interface need to be connected with each other, this connection is sometimes hindered by signature mismatches. In the world of object-oriented programming where objects play a key role, one important signature mismatch problem occurs when the expected interface expects an object data type that is per se incompatible, although semantically equal, to the object data type delivered by the provided interface. For example, suppose a birthday calendar is the parameter type expected by the expected interface, but another birthday calendar from another developer is the provided parameter type, then a mismatch on object data type occurs. To solve this problem, adaptation is one potential solution. However, because some programming language constructs are not amenable to adaptation, a mechanism based on transformation can be used instead to complement the adaptation process. The challenge is to retrieve the state of the object instance delivered by the provided interface, and to set it to an instance of the object type by the expected interface. In the literature, this problem, however, has been not tackled so far by the object-oriented community. This position paper aims to highlight this challenge and motivate the development of future adaptation tools to solve this problem fully automatically. The challenge is illustrated by typical transformation examples, ranging from more or less trivial to quite challenging tasks.