Using Overloading to Express Distinctions Between Evaluators

. Evaluators, also called "interpreters", play a variety of roles in the study of programming languages. Given this, it's surprising that we don't have a better framework for developing evaluators and specifying their relationship to each other. This paper shows that type classes in HASKELL provide an excellent framework for exploring relationships between evaluators, using abstract interpretation as a motivating example. 1. Introduction Evaluators, also called "interpreters", play a variety of roles in the study of programming languages. They define the meaning of programs [7], support the development of new language paradigms [3], relate abstract semantics of programs to the corresponding concrete semantics [2], provide debugging information [5], and yet are simple enough to teach students about the implementation of programming languages. Given this, it's surprising that we don't have a better framework for developing evaluators and specifying their relationship to each other. For ..