Interface compilation: steps toward compiling program interfaces as languages

Interfaces-the collection of procedures and data structures that define a library, a subsystem, a module-are syntactically poor programming languages. They have state (defined both by the interface's data structures and internally), operations on this state (defined by the interface's procedures), and semantics associated with these operations. Given a way to incorporate interface semantics into compilation, interfaces can be compiled in the same manner as traditional languages such as ANSI C or FORTRAN. The article makes two contributions. First, it proposes and explores the metaphor of interface compilation, and provides the beginnings of a programming methodology for exploiting it. Second, it presents MAGIK, a system built to support interface compilation. Using MAGIK, software developers can build optimizers and checkers for their interface languages, and have these extensions incorporated into compilation, with a corresponding gain in efficiency and safety. This organization contrasts with traditional compilation, which relegates programmers to the role of passive consumers, rather than active exploiters of a compiler's transformational abilities.