Scoping Constructs for Software Generators

A well-known problem in program generation is scoping. When identifiers (i.e., symbolic names) are used to refer to variables, types, or functions, program generators must ensure that generated identifiers are bound to their intended declarations. This is the standard scoping issue in programming languages, only automatically generated programs can quickly become too complex and maintaining bindings manually is hard. In this paper we present generation scoping: a language mechanism to facilitate the handling of scoping concerns. Generation scoping offers control over identifier scoping beyond the scoping mechanism of the target programming language (i.e., the language in which the generator output is expressed). Generation scoping was originally implemented as an extension of the code template operators in the Intentional Programming platform, under development by Microsoft Research. Subsequently, generation scoping has also been integrated in the JTS language extensibility tools. The capabilities of generation scoping were invaluable in the implementation of two actual software generators: DiSTiL (implemented using the Intentional Programming system), and P3 (implemented using JTS).