Publication Date

Fall 2012

Degree Type

Master's Project

Degree Name

Master of Science (MS)


Computer Science


This project presents the static type checkers that I developed for the optional type system of the Dart programming language. Dart is an optionally typed language and as a result has an unsound type system. In this project I have created the static type checker tools for dart. The first static type checker tool ensures mandatory typing of Dart code. This checker can be invoked by giving a new compiler option that I have added to the compiler configuration. This checker will help in catching any type errors early at compile time rather than at run time. The second static type checker improves the Dart’s support for covariant generics. This static checker issues warnings at compile time if the covariant use of generics is followed by a modification of the collection passed covariantly. I have also introduced three annotations that will add more type safety to the Dart programming language. The @notnull annotation is to ensure that null values are not passed as arguments to method parameters. This nullness checker ensures that a running program will never throw a null pointer exception. The @modifies annotation supports the covariance check. The @linear annotation is used to prevent unexpected modification of objects by aliasing. The @linear annotation can be used in conjunction with Dart isolates for concurrent programming.