Executable semantics for PLEXIL : simulating a task-scheduling language in Haskell

Abstract

An interdisciplinary study into the theory of design decisions has yielded a model for tracking design changes in hardware/software systems, but it still needs to be applied to a larger system to test its efficiency at tracking important data. This thesis creates an implementation of PLEXIL, a language in development at NASA for controlling various hardware systems, as a testbed for applying the model of design decisions. This PLEXIL implementation is embedded in the functional language Haskell to take advantage of its static typing and lazy evaluation, and it accurately follows the semantics defined by NASA. The external world representation in this thesis improves upon NASA’s current simulator through the definition of new data types for more dynamic runtime behavior.