Title
Refactoring and representation independence for class hierarchies
Abstract
Refactoring transformations are important for productivity and quality in software evolution. Modular reasoning about semantics preserving transformations is difficult even in typed class-based languages because transformations can change the internal representations for multiple interdependent classes and because encapsulation can be violated by pointers to mutable objects. In this paper, an existing theory of representation independence for a single class, based on a simple notion of ownership confinement, is generalized to a hierarchy of classes and used to prove refactoring rules that embody transformations of complete class trees. This allows us to formalize refactorings that inherently involve class inheritance, such as Pull Up or Push Down Field; moreover, this makes it possible to generalize refactorings previously restricted to change of data representation of private attributes (like Extract Class and Encapsulate Field) to address data refinement of protected attributes, dealing with the impact that the corresponding transformations may cause in the subclasses. The utility of the proposed rules is shown in a relatively extensive case study. Shortcomings of the theory are described as a challenge to other approaches to heap encapsulation and relational reasoning for classes.
Year
DOI
Venue
2012
10.1016/j.tcs.2012.02.009
Theor. Comput. Sci.
Keywords
DocType
Volume
single class,internal representation,class inheritance,existing theory,Encapsulate Field,representation independence,class hierarchy,data refinement,heap encapsulation,multiple interdependent class,data representation,complete class tree
Journal
433,
ISSN
Citations 
PageRank 
0304-3975
4
0.44
References 
Authors
24
3
Name
Order
Citations
PageRank
David Naumann1110184.12
Augusto Sampaio29613.42
Leila Silva37810.11