Supporting Software Sustainability with Lightweight Specifications

Lightweight specifications support software maintainability

by providing a way to verify that any changes to a code

base preserve certain program properties. We give two examples

of lightweight specifications for numerical code: units-of-measure

types which specify the physical units of numerical quantities in

a program; and stencil specifications which describe the pattern

of data access used in array computations. Not only can we

automatically verify that a program correctly implements these

requirements but specifications provide documentation for future

developers. Specifications can also be inferred and generated

automatically in some cases, further reducing programmer effort.

We finish by identifying future potential specification techniques

to ease the maintenance and comprehension of scientific code.