Interface compilation: Steps toward compiling program interfaces as languages

Interfaces-the collection of procedures and data structures that define a l ibrary, a subsystem, a module-are syntactically poor programming languages. They have state (defined both by the interface's data structures and inter nally), operations on this state (defined by the interface's procedures), a nd semantics associated with these operations. Given a way to incorporate i nterface semantics into compilation, interfaces can be compiled in the same manner as traditional languages such as ANSI C or FORTRAN. This paper make s two contributions. First, ii proposes and explores the metaphor of interf ace compilation, and provides the beginnings of a programming methodology f or exploiting it. Second, ii presents MAGIK, a system built to support inte rface compilation. Using MAGIK, software developers call build optimizers a nd checkers for their interface languages, and have these extensions incorp orated 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 exploiter s of a complier's transformational abilities.