Polymorphic Types in ACL2

Abstract

This paper describes a tool suite for the ACL2 programming language which incorporates certain ideas from the Hindley-Milner paradigm of functional programming (as exemplified in popular languages like ML and Haskell), including a "typed" style of programming with the ability to define polymorphic types. These ideas are introduced via macros into the language of ACL2, taking advantage of ACL2's guard-checking mechanism to perform type checking on both function definitions and theorems. Finally, we discuss how these macros were used to implement features of Specware [1], a software specification and implementation system.

Fix Your Types

“…Selfridge and Smith [17] created a macro library that supports a form of polymorphism by automating the creation of instances of the defsum macro. Polymorphic functions are then supported by another set of macros that allow one to instantiate a template function definition with different substitutions for type variables.…”