The Ts Type System

The Typed Smalltalk project is building an optimizing compiler for a variant of Smalltalk. Typed Smalltalk differs from Smalltalk in that programs can be annotated with type information, which the compiler can use to optimize programs. The type system for Typed Smalltalk is the first type system for a Smalltalk-like language that is both type-safe and flexible enough to handle the kind of polymorphic procedures used in Smalltalk. There is also a type inference system that can infer the type of each procedure. Previous papers have focused on the specification of the type system. This thesis describes the design and implementation of the current Typed Smalltalk (TS) type system. iii ACKNOWLEDGEMENTS I would like to thank Professor Ralph Johnson, my advisor, for his help and guidance; and Professor Justin Graver for his comments and previous work on the type system. Many of the classes he wrote are reused in the type system in this thesis. In addition, I would also like to express my th..