A Reuse Mechanism of Transformation Rules for the SC Language System

Abstract

We are developing the SC language system, which facilitates language extensions by translation into C. SC languages are extended/plain C languages with an S-expression based syntax. This paper shows those problems in this system that we have found during our process of the development of extended languages using this system and our improvement of this system as our solutions to them. In particular, we focus on additional features to extend existing translation phases (transformation rule-sets) between languages. These features employ a mechanism that dynamically determines the transformation function to apply for a single code fragment. We implemented this mechanism by using CLOS and dynamic variables in Common Lisp. The proposed reuse mechanism enables us to implement extended languages only by writing the difference from existing translators including the identity translators into the base languages. It also helps us reuse a commonly-used rule-set as part of the entire translation. We implemented various features as extensions to C including multithreading, garbage collection, and load balancing. This paper discusses the multithreading case and shows the effectiveness of the proposed mechanism.