Title:
Extending Moth to Support Types as Objects

Authors:
Erin Greenwood-Thessman
     Victoria University of Wellington, Wellington, New Zealand
     erin.greenwood-thessman@ecs.vuw.ac.nz
Michael Homer
     Victoria University of Wellington, Wellington, New Zealand
     mwh@ecs.vuw.ac.nz
James Noble
     Victoria University of Wellington, Wellington, New Zealand
     kjx@ecs.vuw.ac.nz

Abstract:
Grace is a gradually typed language. Moth is an implementation of Grace that extends SOMns, an implementation of Newspeak built using Truffle and the GraalVM. Previous work has shown that transient type checks are almost free when types are determined statically and enforced dynamically. Our work has been to implement types as objects that get passed around at runtime. This enables the name resolution for types to use the same mechanism as the rest of the language. Type checks performed on these objects have used several optimisation techniques to match previous performance in most cases.