Locality metrics and program physical structures

Years of programming experience has convinced us that the physical structur e of a program, such as the locations of the program's components, their ca lls, and the depth of nested calls, is important in determining how effecti ve and efficient the program can be debugged and maintained. This paper int roduces a new class of physical metrics, known as locality metric, that mea sures the relative positions of components in a program listing and reveals useful attributes that may affect programmer productivity. The placement o f the components can be determined by a simple algorithm that is of polynom ial time complexity. The paper compares the performance of the algorithm wi th that of an exhaustive search approach and also reports various character istics of the locality metric based on the collected statistical data. The performance shows the feasibility of the algorithm and closeness of its out put to the optimal result found by the exhaustive approach. (C) 2000 Elsevi er Science Inc. All rights reserved.